Test Bank for Karp’s Cell and Molecular Biology, 9th Edition, Gerald Karp, Janet Iwasa, Wallace Mars

Package Title: Test Bank Course Title: Karp9e Chapter Number: 1

Question Type: Multiple Choice

1) Who was the first person to name what he thought were single cells? a) Leeuwenhoek b) Hooke c) Schleiden d) Schwann e) Virchow Answer: b Difficulty: Easy Learning Objective: LO 1.1 Identify the three tenets of cell theory.

Section Reference: Section 1.1 The Discovery of Cells

2) The first compound light microscopes were constructed by the end of the sixteenth century.

What characteristic defines a compound microscope? a) It has a moveable stage. b) It has multiple lenses. c) Its lens is double the size of simple microscopes. d) The lens has two different colors. e) It has two different light sources.

Answer: b Difficulty: Easy Learning Objective: LO 1.1 Identify the three tenets of cell theory.

Section Reference: Section 1.1 The Discovery of Cells

3) Who was the first scientist to examine and describe living cells? a) Leeuwenhoek

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b) Hooke c) Schleiden d) Schwann e) Virchow Answer: a Difficulty: Easy Learning Objective: LO 1.1 Identify the three tenets of cell theory.

Section Reference: Section 1.1 The Discovery of Cells

4) Who is generally credited with the discovery of cells? a) Leeuwenhoek b) Hooke c) Schleiden d) Schwann e) Virchow Answer: b Difficulty: Easy Learning Objective: LO 1.1 Identify the three tenets of cell theory.

Section Reference: Section 1.1 The Discovery of Cells

5) Despite being correct about the first two tenets of the Cell Theory, Schleiden and Schwann made an error about another central feature of cells. What was their mistaken claim? a) They believed that all cells were smaller than 2 µ in diameter. b) They claimed that all cells were exactly the same in every detail. c) They described cells as immortal. d) They agreed that cells could arise from noncellular materials. e) They stated that all cells had nuclei through their entire existence.

Answer: d Difficulty: Medium Learning Objective: LO 1.1 Identify the three tenets of cell theory.

Section Reference: Section 1.1 The Discovery of Cells

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6) Which of the following characteristics is NOT a basic property of cells? a) Cells carry out a variety of emotional reactions. b) Cells engage in numerous mechanical activities. c) Cells generally respond to stimuli. d) Cells are capable of self-regulation. e) Cells evolve.

Answer: a Difficulty: Easy Learning Objective: LO 1.2 Explain the importance of the fundamental properties shared by all cells.

Section Reference: Section 1.2 Basic Properties of Cells

7) Which of the following statements accurately characterize cells? a) Cells are highly complex and organized. b) Cells possess a genetic program and the means to use it. c) Cells are capable of producing more of themselves. d) Cells acquire and utilize energy. e) All choices are correct.

Answer: e Difficulty: Easy Learning Objective: LO 1.2 Explain the importance of the fundamental properties shared by all cells.

Section Reference: Section 1.2 Basic Properties of Cells

8) The first culture of human cells was begun by George and Martha Gey of Johns Hopkins University in 1951. The cells were obtained from a malignant tumor and named ______ cells after the donor, _________. a) MaLe, Mary Leeds b) HeLa, Henrietta Lacks c) Roberts, John Roberts d) MaLe, Martin Lewis e) HeLa, Helen Lassiter Answer: b

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Difficulty: Medium Learning Objective: LO 1.2 Explain the importance of the fundamental properties shared by all cells.

Section Reference: Section 1.2 Basic Properties of Cells

9) Cells grown in culture, outside the body are described as cells grown ________. a) in vivo b) live c) in vitro d) in culturo e) vivacious Answer: c Difficulty: Medium Learning Objective: LO 1.2 Explain the importance of the fundamental properties shared by all cells.

Section Reference: Section 1.2 Basic Properties of Cells

10) A high powered microscope that allows cellular organelles to be examined in great detail is called ___________. a) a refractive microscope b) an electron microscope c) a fluorescence microscope d) a scanning tunneling microscope e) a confocal laser scanning microscope Answer: b Difficulty: Easy Learning Objective: LO 1.2 Explain the importance of the fundamental properties shared by all cells.

Section Reference: Section 1.2 Basic Properties of Cells

11) Which list shows the correct order for cellular complexity from largest to smallest units? a) organelles, polymers, atoms, complexes, molecules b) organelles, complexes, polymers, molecules, atoms

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c) organelles, molecules, complexes, atoms, polymers d) organelles, atoms, molecules, complexes, polymers Answer: b Difficulty: Easy Learning Objective: LO 1.2 Explain the importance of the fundamental properties shared by all cells.

Section Reference: Section 1.2 Basic Properties of Cells

12) The apical ends of intestinal cells face the intestinal channel and have long processes that facilitate the absorption of nutrients. What is the name of these processes and what cytoskeletal element forms their internal skeleton? a) microvilli, microtubules b) villi, microtubules c) microvilli, actin filaments d) villi, actin filaments e) microvilli, intermediate filaments Answer: c Difficulty: Medium Learning Objective: LO 1.2 Explain the importance of the fundamental properties shared by all cells.

Section Reference: Section 1.2 Basic Properties of Cells

13) Virtually all chemical changes that take place in cells require ________, molecules that greatly increase the rate at which a chemical reaction occurs. a) DNAs b) carbohydrates c) ligands d) enzymes Answer: d Difficulty: Easy Learning Objective: LO 1.2 Explain the importance of the fundamental properties shared by all cells.

Section Reference: Section 1.2 Basic Properties of Cells

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14) You are conducting an experiment by trying to reproduce the work performed in 1891 by Hans Driesch, a German embryologist. Working with a fertilized sea urchin egg, you allow it to complete the first cell division after fertilization. You then carefully separate the two cells of the embryo and allow their development to continue. Based on Driesch's experiment, which result below would you expect to happen? a) Both of the cells will die. b) Both of the cells will develop into complete and normal embryos. c) One cell will develop into a normal, though smaller, embryo; the other dies. d) One cell will develop into half an embryo; the other will develop into the other half of the embryo. e) One cell will develop into a defective embryo and the other will die.

Answer: b Difficulty: Hard Learning Objective: LO 1.2 Explain the importance of the fundamental properties shared by all cells.

Section Reference: Section 1.2 Basic Properties of Cells

15) The original cell which arose billions of years ago is referred to by some evolutionary biologists as the __________. a) first universal common ancestor b) last universal common ancestor c) evolutionary tree root d) evolutionary shrub e) first eukaryote Answer: b Difficulty: Medium Learning Objective: LO 1.2 Explain the importance of the fundamental properties shared by all cells.

Section Reference: Section 1.2 Basic Properties of Cells

16) What characteristics distinguish prokaryotic and eukaryotic cells? a) Eukaryotes have membrane-bound organelles; prokaryotes do not. b) Prokaryotes have relatively little DNA; eukaryotes generally have much more.

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c) Eukaryotic chromosomes are linear; prokaryotic chromosomes are circular. d) Eukaryotic DNA is usually heavily associated with protein to form a nucleoprotein complex called chromatin, which is not seen in prokaryotic genetic material. e) All of these are correct.

Answer: e Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

17) Which of the following are NOT considered to belong to the Archaea? a) Methanogens b) Halophiles c) Acidophiles d) Thermophiles e) Eubacteria Answer: e Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

18) Which of the following are considered to be eukaryotes? a) amoebae b) yeast c) holly d) starfish e) all choices are eukaryotic Answer: e Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

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19) The genetic material of a prokaryotic cell is present in the _________, a poorly defined region of the cell that lacks a boundary membrane to separate it from the surrounding cytoplasm. a) nucleus b) chromatic region c) nucleoid d) pharmacopeia e) genetome Answer: c Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

20) Some bacteria can pass a piece of DNA from a donor bacterial cell to a recipient bacterial cell through a structure called a pilus. What is this process called? a) confirmation b) transduction c) transformation d) conjugation e) fission Answer: d Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

21) Cyanobacteria are capable of photosynthesis, but many of them also convert nitrogen gas into reduced forms of nitrogen (such as ammonia) that can be used by cells in the synthesis of nitrogen-containing organic compounds, including amino acids and nucleotides. This process is called ______. a) nitrogen fixation b) denitrification c) nitrification

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d) respiration e) ammoniation Answer: a Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

22) The process by which a relatively unspecialized cell becomes highly specialized is called _______. a) differentiation b) determination c) degeneracy d) denaturation e) renaturation Answer: a Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

23) Bacteria often live in complex, multi-species communities, like the layer of plaque that grows on your teeth; such a community is called _________. a) a biotome b) a microtome c) a biofilm d) an anatome Answer: c Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

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24) The rapidity and cost-efficiency of DNA sequencing has made it possible to sequence virtually all of the genes present in the microbes of a given habitat. This generates a collective genome for that habitat, which has come to be called _________. a) a metachron b) a metagenome c) a netagenome d) a megagene e) an exogenome Answer: b Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

25) The collection of bacteria that live on and within the human body are being isolated, identified and characterized; they are referred to as the human ______. It has been demonstrated that these organisms differ based upon the age, diet, geography and state of health of the human from which they were obtained. a) macrobiome b) metagenome c) minibiome d) microbiome e) homobiome Answer: d Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

26) Studies on mice suggest that bacterial species predominating in obese individuals differ from those in the digestive tracts of lean individuals and that they play a role in weight gain in obese individuals. What are these bacteria in obese individuals proposed to do that increases weight gain in obese individuals? a) They make obese mice eat more food.

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b) They release chemicals that increase the caloric intake by the mice. c) The bacteria in obese individuals may release more calories from digested food than their counterparts in leaner individuals. d) The bacteria in obese individuals turn the food in the intestines to fat. e) The bacteria in obese individuals produce gas that makes their hosts obese.

Answer: c Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

27) Which of the following is NOT a model organism used for understanding basic processes of life? a) Mus musculus b) Drosophila melanogaster c) Homo sapiens d) Arabidopsis thaliana e) Caenorhabditis elegans Answer: c Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

28) The field of biological research in which biologists are attempting to create a living cell in the laboratory, essentially from scratch is known as __________. More modestly, this branch of biology also has a goal of developing novel life forms, beginning with existing organisms, that have a unique value in medicine, industry or in cleaning up the environment. a) megalomaniacal biology b) synthetic biology c) production-grade biology d) industrial biology e) pharmaceutical biology Answer: b

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Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

29) What is the most appropriate unit of measurement for macromolecular complexes including ribosomes and microfilaments? a) picometers b) angstroms c) nanometers d) micrometers e) centimeters Answer: c Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

30) What is the most appropriate unit of measurement for most types of cells? a) picometers b) angstroms c) nanometers d) micrometers e) centimeters Answer: d Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

31) Which statement is NOT correct regarding Archaea? a) They are considered more closely related to bacteria than to eukarya.

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b) Some are able to generate methane from carbon dioxide and hydrogen gases. c) Some are halophiles capable of surviving in a 5M osmolality. d) Some can survive temperatures above 120oC. Answer: a Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

32) The flagellum of E. coli is chemically most similar to the flagellum of _______________. a) a human sperm cell b) a protist c) green algae like Euglena d) the bacterium Salmonella e) all are made of the same molecules Answer: d Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

33) Which of the following is NOT a feature shared by all cells? a) plasma membrane with similar chemical construction b) genetic information encoded in DNA nucleotides c) shared metabolic pathways d) division of cells into nucleus and cytoplasm e) similar energy storing chemicals such as ATP Answer: d Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

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34) Which feature is unique to some eukaryotic cells and never seen in prokaryotic cells? a) plasma membrane with similar chemical construction b) phagocytic ability c) shared metabolic pathways d) genetic information encoded in DNA nucleotides e) cytoskeletal filaments built of proteins such as actin and tubulin Answer: b Difficulty: Hard Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

35) Which feature is shared by both prokaryotic and eukaryotic cells? a) complex chromosomes capable of forming condensed chromatin b) complex cilia and flagella c) photosystems housed in chloroplast membranes d) cell division employing a mitotic spindle e) diploid chromosomes inherited from several parents Answer: b Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

36) Which organelle is found in both eukaryotes and prokaryotes? a) nucleus b) mitochondria c) endoplasmic reticulum d) proteasome e) Golgi apparatus Answer: d

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Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

37) Which statement is NOT correct when describing eukaryotic and bacterial flagella? a) they generate movement by different mechanisms b) the bacterial flagellum is more complex c) the eukaryotic flagellum is not found on all cells d) the bacterial flagellum can rotate at speeds greater than 1,000 rotations per second e) all flagella allow cells possessing them to exhibit motility Answer: b Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

38) The term used to describe the life forms capable of withstanding a variety of harsh environments is: a) methanogen b) halophile c) extremophile d) thermophile e) normophile Answer: c Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

39) Which of these cell types does NOT possess membrane-bound organelles? a) human cells b) Volvox cells

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c) E. coli d) yeast cells e) plant cells Answer: c Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

40) Which of the following statements about viruses is NOT true? a) All viruses are obligatory intracellular parasites. b) All viruses are obligatory intercellular parasites. c) Viruses occur in a wide variety of very different shapes, sizes and constructions. d) A viral host may be a plant, animal or bacterial cell. e) Viral genetic material can be either RNA or DNA. Answer: b Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

41) Outside of a living cell, the virus exists as a particle called ________, which is little more than a macromolecular package. a) a virulent b) a virusette c) a virulant d) a virion e) an infectoid Answer: d Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

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42) Viruses like adenovirus, which causes respiratory infections in mammals, have a 20-sided polyhedral capsid. What is this polyhedral shape called? a) a tetrahedron b) a dodechedron c) a polygon d) an icosahedron e) an octahedron Answer: d Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

43) Usually, a virus infects a cell and arrests the normal synthetic activities of the host, redirecting the cell to use its available materials to manufacture viral nucleic acids and proteins, which assemble into new viruses. Ultimately, the infected cell ruptures and releases a new generation of viral particles that can infect neighboring cells. This type of infection is called _________ infection. a) a lytic b) a proviral c) an eluctable d) a virulent e) an avirulent Answer: a Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

44) In some cases, an infecting virus does not lead to the death of the host cell, but instead integrates its DNA into the DNA of the host cell's chromosomes. Integration of the viral DNA can have different effects; for example, the infected cell might exhibit normal behavior until exposure to a stimulus that activates the dormant viral DNA, triggering production of viral progeny that bud off of the infected cell or a loss of control over growth and division leading to malignancy. Such an infection is referred to as ______ infection. a) a lytic b) a proviral

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c) an eluctable d) a virulent e) an avirulent Answer: b Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

45) From what is the lipid-containing outer envelope surrounding the viral capsid of many animal viruses usually derived? a) the nuclear envelope b) the outer mitochondrial membrane c) the plasma membrane d) the lysosomal membrane e) the outer membrane of the chloroplast Answer: c Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

46) Which of the following is NOT typically a behavior exhibited by a cell with a proviral infection? a) Immediate production of new viruses and subsequent lysis of the host cell. b) Normal behavior until exposure to a stimulus, like UV radiation, that activates dormant viral DNA, leading to lysis of the host cell and release of viral progeny. c) Production of new viral progeny that bud at the cell surface without lysing the infected cell. d) Loss of control in animal cells over their growth and division followed by malignancy.

Answer: a Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

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47) What advantageous uses have viruses been shown to have? a) The activities of viral genes mimic those of host genes so they are useful for studying mechanisms of DNA replication and gene expression in their much more complex hosts. b) They can be used as a means to introduce foreign genes into human cells, which may serve as a basis for treatment of human diseases by gene therapy. c) Insect-killing viruses may play an increasing role in the war against insect pests. d) Bacteria-killing viruses may play an increasing role in the war against bacterial pathogens. e) All of these are correct.

Answer: e Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

48) Potato spindle-tuber disease, which causes potatoes to become gnarled and cracked, is caused by an infectious agent consisting of a small circular RNA molecule that totally lacks a protein coat. These infectious agents are thought to exert their effects by interfering with the cell's normal path of gene expression. Such an infectious agent is known as __________. a) a provirous b) a bacteriophage c) a viroid d) a virunette e) an eviscerion Answer: c Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

49) What major feature distinguishes the theoretical first eukaryotic common ancestor (FECA) from prokaryotes? a) DNA b) closed internal compartments c) plasma membrane d) ribosomes e) heterotrophy

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Answer: b Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

50) Prokaryotic cells have been identified in rock dated at ____________. a) 2.7 million years old b) 2.7 billion years old c) 2.4 million years old d) 2.4 billion years old e) 4 billion years old Answer: b Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

51) Evidence of prokaryotes in the fossil record precedes eukaryotic cells by: a) around 1 billion years b) 4 billion years c) 10 billion years d) both appear at the same time in the fossil record Answer: a Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

52) Lynn Margulis’s resurrected hypothesis that eukaryotic evolution was partly a result of the internal residence of prokaryotic organisms is termed the _________________ theory. a) phagocytosis b) ingestion

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c) endosymbiont d) invasive e) digestion Answer: c Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

53) The term _____________ describes the ability of a life form to synthesize its organic molecules from other organic nutrients. a) autotroph b) heterotroph c) phototroph d) chemotroph e) lithotroph Answer: b Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

54) Which of these terms describes an organism which metabolizes by using oxygen and builds cellular materials from other organic compounds? a) anaerobic heterotroph b) aerobic heterotroph c) anaerobic autotroph d) aerobic autotroph Answer: b Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

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55) The ancestral cell which had characteristics including mitochondria, evolutionarily derived functions such as intron splicing, ability to undergo meiosis, and cytoskeletal elements has been termed the _________________. a) LUCA (last universal common ancestor) b) FECA (first eukaryotic common ancestor) c) LECA (last eukaryotic common ancestor) d) FUCA (first universal common ancestor) Answer: c Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

56) Which organelle is believed to have been acquired by eukaryotic cells most recently? a) mitochondria b) Golgi apparatus c) chloroplasts d) lysosomes e) endoplasmic reticulum Answer: c Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

57) What is thought to explain why Preaxostyla is a eukaryote without mitochondria? a) this lineage of eukaryotic cells never inherited mitochondria b) the mitochondria mutated into another organelle c) the mitochondria are digested by lysosomes d) the mitochondria were lost Answer: d Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

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58) Who proposed that life forms should be categorized into three distinct evolutionary lines rather than the traditionally accepted two lines of prokaryotes and eukaryotes? a) Lynn Margulis b) Carl Woese c) Charles Darwin d) Gregor Mendel e) Watson and Crick Answer: b Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

59) Which term is now used to describe the three distinct evolutionary lines proposed by Carl Woese and his colleagues? a) Kingdoms b) Domains c) Phyla d) Clades e) Species Answer: b Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

60) Supergroups of eukaryotic organisms are mostly separate groups of: a) animals b) plants c) protists d) viruses e) algae Answer: c

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Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

61) The major lineages derived from LECA (last eukaryotic common ancestor) are termed _______________________. a) kingdoms b) domains c) phyla d) supergroups e) species Answer: d Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

62) The supergroup containing animals is __________________. a) Opisthokonta b) Amoebozoa c) Excavata d) Archaeplastida e) SAR Answer: a Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

63) The supergroup containing fungi is __________________. a) Opisthokonta b) Amoebozoa c) Excavata d) Archaeplastida e) SAR

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Answer: a Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

64) The supergroup containing plants is __________________. a) Opisthokonta b) Amoebozoa c) Excavata d) Archaeplastida e) SAR Answer: d Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

65) The supergroup containing protozoan parasites such as Giardia is __________________. a) Opisthokonta b) Amoebozoa c) Excavata d) Archaeplastida e) SAR Answer: c Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

66) The supergroup containing ciliated protozoa is __________________. a) Opisthokonta b) Amoebozoa c) CCTH

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d) Archaeplastida e) SAR Answer: e Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

67) The supergroup containing the most obscure and poorly understood protozoa is __________________. a) Opisthokonta b) Amoebozoa c) Excavata d) CCTH e) SAR Answer: d Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

68) Which of these pairs of life forms are considered to be most closely related? a) animals and plants b) plants and fungi c) animals and fungi d) Giardia and ciliated protozoa e) amoebae and ciliated protozoa Answer: c Difficulty: Hard Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

69) Which of these pairs of life forms are considered to be most closely related?

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a) green algae and brown algae b) plants and fungi c) plants and green algae d) Giardia and ciliated protozoa e) amoebae and ciliated protozoa Answer: c Difficulty: Hard Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

70) Given that cells possess genes from a variety of different ancestral sources, deciding which to use for evolutionary relatedness comparisons can be complicated. The best candidates for determining phylogenetic relationships tend to be ________________. a) informational genes because they operate singly and uniquely b) metabolic activity-related genes because they operate singly and uniquely c) informational genes because they encode components which are parts of large complexes and conservation of structure is required d) metabolic activity-related genes because they encode enzymes which are parts of large complexes and conservation of structure is required e) all gene types provide the same phylogenetic accuracy Answer: c Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

71) Yeast genome analysis has revealed a mixed ancestry of eubacterial and archaebacterial gene inheritance. Studies presently show: a) archaeal character in metabolic genes and eubacterial character in the informational genes b) eubacterial character in metabolic genes and archaeal character in the informational genes c) eubacterial character in informational and metabolic genes and archaeal character in cell wall genes d) archaeal character in informational and metabolic genes and eubacterial character in cell wall genes e) eubacterial character in informational and metabolic genes and archaeal character in motility genes

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Answer: b Difficulty: Hard Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

72) The best explanation of what defines a multicellular organism, as opposed to a colonial one, is that: a) a multicellular organism can exist and propagate as both a single-celled or a multicelled form. b) a multicellular organism can only exist and propagate as a multicelled form. c) a multicellular organism can only exist and propagate as a single-celled form. d) a multicellular organism shows signs of cellular differentiation throughout its life cycle.

Answer: b Difficulty: Medium Learning Objective: LO 1.5 Differentiate a colony of individual single-celled organisms from a multicellular organism.

Section Reference: Section 1.5 Green Cells: Volvox, an Experiment in Multicellularity 73) Volvox is characterized by possessing ____________ cells. a) 4 b) around 100 c) 1,000 or more d) millions of Answer: c Difficulty: Easy Learning Objective: LO 1.5 Differentiate a colony of individual single-celled organisms from a multicellular organism.

Section Reference: Section 1.5 Green Cells: Volvox, an Experiment in Multicellularity

74) Volvox is a member of the supergroup __________________. a) Opisthokonta b) Amoebozoa c) CCTH d) Archaeplastida e) SAR

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Answer: d Difficulty: Easy Learning Objective: LO 1.5 Differentiate a colony of individual single-celled organisms from a multicellular organism.

Section Reference: Section 1.5 Green Cells: Volvox, an Experiment in Multicellularity

75) It is believed that _____________ and ________________ evolved from _________________. a) plants, Volvox, a common ancestor b) land plants, aquatic plants, Volvox c) land plants, Volvox, aquatic plants d) Volvox, aquatic plants, land plants Answer: a Difficulty: Medium Learning Objective: LO 1.5 Differentiate a colony of individual single-celled organisms from a multicellular organism.

Section Reference: Section 1.5 Green Cells: Volvox, an Experiment in Multicellularity

76) Volvox possesses enlarged cells called _____________ which have a reproductive function. a) gametes b) ova c) gonidia d) spermatogonia e) oogonia Answer: c Difficulty: Easy Learning Objective: LO 1.5 Differentiate a colony of individual single-celled organisms from a multicellular organism.

Section Reference: Section 1.5 Green Cells: Volvox, an Experiment in Multicellularity

77) What characteristic of collagen makes it a suitable material for inclusion in tissue engineering experiments?

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a) elasticity b) degradability c) adhesiveness d) immunogenicity e) good electrical conductivity Answer: b Difficulty: Easy Learning Objective: LO 1.6 Describe how tissue engineering can create cell-based replacement organs.

Section Reference: Section 1.6 Engineering Linkage: Tissue Engineering

78) Which of these is a man-made biodegradable polymer? a) collagen b) poly-lactic acid c) lactate d) silk fiber e) all choices are correct Answer: b Difficulty: Easy Learning Objective: LO 1.6 Describe how tissue engineering can create cell-based replacement organs.

Section Reference: Section 1.6 Engineering Linkage: Tissue Engineering

Question Type: Multiple Select

79) Which of the following is a tenet of the Cell Theory? (Select all correct choices) a) All organisms are composed of one or more cells. b) The cell is the structural unit of life. c) Cells can arise only by division from a preexisting cell. d) Cells divide only by fission.

Answer: a, b, c

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Difficulty: Medium Learning Objective: LO 1.1 Identify the three tenets of cell theory.

Section Reference: Section 1.1 The Discovery of Cells

80) What factor or factors discovered with electron microscopy distinguished prokaryotic from eukaryotic cells? (Select all correct choices) a) their size b) their color c) the types of their internal structures or organelles d) their fragility Answer: a, c Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

Question type: Multiple Choice

81) Archaea are found in environments with which characteristics? a) extreme salinity b) low pH c) extreme heat d) normal temperature ranges e) All of the choices are correct.

Answer: e Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

Question type: Multiple Select

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82) You find a single-celled organism which you believe is a new eukaryotic life form. Which features might it possess if it is average in most of its characteristics? (Select all correct choices) a) genome encoding around 1,000 proteins b) genome encoding more than 6,000 proteins c) 4 million base pairs of DNA d) 8 million base pairs of DNA e) 16 million base pairs of DNA Answer: b, e Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

83) According to the text, in which environments have bacteria been isolated? (Select all correct choices) a) Antarctic ice shelves b) dry deserts c) mile-deep rock layers d) molten magma e) human intestines Answer: a, b, c, e Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

84) Why are viruses NOT considered to be organisms and not described as being alive? (Select all correct choices) a) Viruses are unable to reproduce by themselves. b) Viruses are not able to metabolize by themselves. c) Viruses are not able to synthesize DNA by themselves. d) Viruses are not able to assemble spontaneously.

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Answer: a, b, c Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

85) Among the most complex viruses are the ________, which are also the most abundant biological entities on Earth. (Select all correct descriptive terms) a) mammalian viruses b) bacterial viruses c) vibriovirions d) bacteriophages Answer: b, d Difficulty: Easy Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

86) Acquisition of cyanobacterium-like cells by an early heterotrophic anaerobe changed the cell’s ability to _______________. (Select all correct choices) a) acquire its organic building blocks b) live in an oxygen containing environment c) create ATP in mitochondria d) synthesize DNA in a nucleus e) traffic molecules through membranous organelles like the Golgi apparatus Answer: a, b Difficulty: Hard Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

87) Which abilities/characteristics are thought to have been possessed by LECA (last eukaryotic common ancestor) but NOT by FECA (first eukaryotic common ancestor)? (Select all correct choices) a) ability to synthesize internal membranes

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b) phagocytic ability c) ability to splice introns d) development of meiosis e) possession of mitochondria Answer: c, d, e Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

88) Which abilities/characteristics are thought to have been possessed by both LECA (last eukaryotic common ancestor) and by FECA (first eukaryotic common ancestor)? (Select all correct choices) a) ability to synthesize internal membranes b) phagocytic ability c) ability to splice introns d) development of meiosis e) possession of mitochondria Answer: a, b Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

89) Gene transfer from one organism to another within the same generation of cells is termed _____________. (Select all correct choices) a) parental gene transfer b) horizontal gene transfer c) vertical gene transfer d) lateral gene transfer e) endosymbiont gene transfer Answer: b, d Difficulty: Medium Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

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90) Examples of the types of informational gene which provide accurate phylogenetic relationship determinations include: (Select all correct choices) a) ribosomal RNA genes b) genes encoding cell membrane signal proteins c) DNA polymerase genes d) transfer RNA genes e) genes encoding metabolic activities Answer: a, c, d Difficulty: Hard Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

91) Which of these are viable suggestions to explain the mixed character of the eukaryotic genome? (Select all correct choices) a) an archaebacterial cell fused with a eubacterial cell and the genomes integrated b) eubacterial genes migrated from chloroplasts and mitochondria to become nuclear genes c) eukaryotic genes migrated from chloroplasts and mitochondria to become nuclear genes d) eukaryotic cells evolved from archaebacterial ancestors and then picked up eubacterial genes e) archaebacterial genes migrated from chloroplasts and mitochondria to become nuclear genes Answer: a, b, d Difficulty: Hard Learning Objective: LO 1.4 Distinguish the structures and functions of viruses and viroids.

Section Reference: Section 1.4 Viruses and Viroids

92) A typical example of a colonial organism is: (Select all correct choices) a) plasmodial slime mold b) Volvox c) Dictyostelium d) Gonium e) Pleodornium Answer: a, c

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Difficulty: Easy Learning Objective: LO 1.5 Differentiate a colony of individual single-celled organisms from a multicellular organism.

Section Reference: Section 1.5 Green Cells: Volvox, an Experiment in Multicellularity

93) What materials are found in fully artificial organs? (Select all correct choices) a) plastics b) ceramics c) electronics d) heavy metals e) recombinant cells Answer: a, c Difficulty: Easy Learning Objective: LO 1.6 Describe how tissue engineering can create cell-based replacement organs.

Section Reference: Section 1.6 Engineering Linkage: Tissue Engineering

94) What materials are being researched in constructing cell-based replacement organs? (Select all correct choices) a) plastic 3-D scaffolds b) tissue cells from the patient requiring the organ replacement c) collagen fibrils d) electronics e) blood cells from the patient requiring the organ replacement Answer: a, b, c, e Difficulty: Easy Learning Objective: LO 1.6 Describe how tissue engineering can create cell-based replacement organs.

Section Reference: Section 1.6 Engineering Linkage: Tissue Engineering

95) Scaffolds for tissue engineering need to be porous because: (Select all correct choices) a) this creates more surface area for cell adhesion b) this will allow access for electronic circuitry to be connected to cells in the replacement organ

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c) nutrient and waste diffusion will be more effective d) the scaffold will be more rigid and strong e) the scaffold will be more likely to be accepted by the immune defenses of the body Answer: a, c Difficulty: Medium Learning Objective: LO 1.6 Describe how tissue engineering can create cell-based replacement organs.

Section Reference: Section 1.6 Engineering Linkage: Tissue Engineering

96) How have scientists attempted to create a porous scaffold for tissue engineering? (Select all correct choices) a) through a process known as electrospinning b) by using spider web silk c) by use of ultraviolet light-induced degradation of plastics d) by electron bombardment of plastics e) by forcing gases through a liquid matrix material Answer: a, e Difficulty: Easy Learning Objective: LO 1.6 Describe how tissue engineering can create cell-based replacement organs.

Section Reference: Section 1.6 Engineering Linkage: Tissue Engineering

97) Viable adult stem cells have been located in _________________ tissue. (Select all correct choices) a) muscle b) nervous c) bone marrow d) fat e) dead Answer: a, b, c, d Difficulty: Easy Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Page 37

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

98) Types of stem cells include: (Select all correct choices) a) adult stem cells b) undifferentiated embryonic stem cells c) induced pluripotent stem cells d) undifferentiated pluripotent stem cells e) induced adult stem cells Answer: a, b, c Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

99) Likely potential benefits from research using induced pluripotent stem cells include: (Select all correct choices) a) advances in individualized cell replacement therapies b) creating cells with disease specific phenotypes to better understand some clinical conditions c) creating designer drugs for treating disease d) advances in gene therapy e) advances in bacteriophage therapy Answer: a, b Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

100) Risks associated with embryonic stem cell therapies include: (Select all correct choices) a) development of cancer b) immunological rejection of transplants created for unrelated organ recipients c) development of teratomas d) complications with the use of non-human biological materials e) competition with the technology used in employing induced pluripotent stem cell technology

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Answer: b, c, d Difficulty: Medium Learning Objective: LO 1.3 Compare the structures and functions of prokaryotic and eukaryotic cells.

Section Reference: Section 1.3 Two Fundamentally Different Classes of Cells

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Package Title: Test Bank Course Title: Karp9e Chapter Number: 2

Question Type: Multiple Choice

1) Elements are likely to exhibit similar properties if: a) they have the same number of electrons in their innermost orbital b) they have the same number of electrons in their outermost orbital c) they have the same number of electrons in their innermost electron shell d) they have the same number of electrons in their outermost electron shell Answer: d Difficulty: Easy

Learning Objective: LO 2.1 Describe the role of electrons in the formation of covalent bonds.

Section Reference: Section 2.1 Covalent Bonds

2) The two elements most likely to exhibit similar reactive properties are: a) lithium and neon b) carbon and chlorine c) oxygen and sulfur d) sodium and fluorine Answer: c Difficulty: Medium

Learning Objective: LO 2.1 Describe the role of electrons in the formation of covalent bonds.

Section Reference: Section 2.1 Covalent Bonds

3) Which of these atoms is the LEAST likely to form bonds with others? a) neon

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b) carbon c) fluorine d) lithium e) hydrogen Answer: a Difficulty: Easy Learning Objective: LO 2.1 Describe the role of electrons in the formation of covalent bonds.

Section Reference: Section 2.1 Covalent Bonds

4) The electronegativity of an atom is related to the: a) number of electrons in its nucleus b) number of neutrons in its nucleus c) number of protons in its nucleus d) the combined number of neutrons and protons in its nucleus

Answer: c Difficulty: Medium Learning Objective: LO 2.1 Describe the role of electrons in the formation of covalent bonds.

Section Reference: Section 2.1 Covalent Bonds

5) Inert biological molecules like fats and waxes are chemically characterized by possessing many: a) non-polar covalent bonds b) ionic bonds c) polar covalent bonds d) oxygen, nitrogen or sulfur atoms

Answer: a Difficulty: Medium Learning Objective: LO 2.1 Describe the role of electrons in the formation of covalent bonds.

Section Reference: Section 2.1 Covalent Bonds

6) Extremely high levels of electronegativity can result in the formation of: a) non-polar covalent bonds b) ionic bonds c) polar covalent bonds d) oxygen, nitrogen or sulfur atoms

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Answer: b Difficulty: Easy Learning Objective: LO 2.1 Describe the role of electrons in the formation of covalent bonds.

Section Reference: Section 2.1 Covalent Bonds

7) Which statement does NOT support the theory that aging may occur in response to cellular damage by free radicals? a) Mice genetically engineered to express higher levels of catalase lived 20% longer than control mice. b) Mice lacking mitochondrial superoxide dismutase died after a few weeks of life. c) Bacteria and yeast cells incapable of expressing superoxide dismutase cannot live in an oxygen-containing environment. d) Rats and mice fed high levels of antioxidants age at the same rate as those on a standard diet.

Answer: d Difficulty: Medium Learning Objective: LO 2.1 Describe the role of electrons in the formation of covalent bonds.

Section Reference: Section 2.1 Covalent Bonds

8) Which of these bonds results from an unequal sharing of electrons? a) ionic bond b) polar covalent bond c) triple bond d) nonpolar covalent bond Answer: b Difficulty: Easy

Learning Objective: LO 2.1 Describe the role of electrons in the formation of covalent bonds.

Section Reference: Section 2.1 Covalent Bonds

9) Under which circumstances would electrons be most likely to be shared equally? a) when they are equidistant from nuclei b) when they are equidistant from each other c) when atoms of the same element are sharing them d) when the atoms sharing them are different Answer: c

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Difficulty: Easy

Learning Objective: LO 2.1 Describe the role of electrons in the formation of covalent bonds.

Section Reference: Section 2.1 Covalent Bonds

10) Which of the following elements are commonly found in biological molecules and strongly electronegative? a) oxygen and carbon b) oxygen and phosphorus c) oxygen and nitrogen d) carbon and nitrogen e) carbon and sodium Answer: c Difficulty: Easy

Learning Objective: LO 2.1 Describe the role of electrons in the formation of covalent bonds.

Section Reference: Section 2.1 Covalent Bonds

11) The most stable atoms, and thus those that are typically nonreactive, are the atoms that have _______. a) equal numbers of electrons and protons b) equal numbers of electrons and neutrons c) full inner electron shells d) full outer electron shells e) all covalent bonds Answer: d Difficulty: Easy

Learning Objective: LO 2.1 Describe the role of electrons in the formation of covalent bonds.

Section Reference: Section 2.1 Covalent Bonds

12) The isotope of hydrogen which is radioactive ________________________. a) possesses three neutrons and is called tritium b) possesses two neutrons and is called tritium c) possesses three neutrons and is called deuterium d) possesses two neutrons and is called deuterium Answer: b Difficulty: Easy Page 4

Learning Objective: LO 2.2 Explain the chemical basis of the use of radionuclides in imaging and treatment.

Section Reference: Section 2.2 Engineering Linkage: Radionuclides for Imaging and Treatment

13) Which of these isotope emissions is LEAST likely to be useful for radiation therapy in cancer patients? a) alpha particles b) gamma rays c) X-rays d) beta particles Answer: a Difficulty: Medium

Learning Objective: LO 2.2 Explain the chemical basis of the use of radionuclides in imaging and treatment.

Section Reference: Section 2.2 Engineering Linkage: Radionuclides for Imaging and Treatment

14) A highly focused treatment for brain cancer relies upon _____________________. a) 125I nuggets hemisperically arranged around the tumor, emitting convergent alpha particle beams which create the so-called alpha knife. b) 99Tc nuggets hemisperically arranged around the tumor, emitting convergent X ray beams which create the so-called X ray knife. c) 60Co nuggets hemisperically arranged around the tumor, emitting convergent gamma ray beams which create the so-called gamma knife. d) 99Mo nuggets hemisperically arranged around the tumor, emitting convergent beta ray beams which create the so-called beta knife.

Answer: c Difficulty: Medium

Learning Objective: LO 2.2 Explain the chemical basis of the use of radionuclides in imaging and treatment.

Section Reference: Section 2.2 Engineering Linkage: Radionuclides for Imaging and Treatment

15) Which of the groups participates exclusively in hydrophobic interactions?

Page 5

OH

a..

d.

b.

CH2

OH

H

H

SH H

H

C

C

C

C

C

H

H

H

H

H

H

H

H

C

C

C

H

H

H

e..

CH 3 H

c..

H

H

CH 2

C

C

C

H

H

NH2

H

H

a) a b) b c) c d) d e) e Answer: e Difficulty: Medium

Learning Objective: LO 2.3 Describe the role of noncovalent bonds in the structure of molecules such as water.

Section Reference: Section 2.3 Noncovalent Bonds

16) Which of the groups participates exclusively in hydrophilic interactions?

CH 3 a.

H

H

H

H

H

C

C

C

C

C

H

H

H

H

H

d.

OH H

b.

c.

C O

OH

e.

a) a b) b c) c d) d e) e Answer: b Difficulty: Medium

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H

H

C

O

C

C

C

H

H

H

SH

H

H

NH 2

C

C

C

H

H

OH

H

Learning Objective: LO 2.3 Describe the role of noncovalent bonds in the structure of molecules such as water.

Section Reference: Section 2.3 Noncovalent Bonds

17) Why are free ionic bonds of little relevance and relatively unlikely to form in living organisms?

1) Cells are composed mostly of water, which interferes with ionic bonds between free ions.

2) Cells are largely hydrophobic and exclude ions.

3) Cells incorporate ions into larger molecules and prevent the formation of ionic bonds.. a) 1 b) 2 c) 3 d) 1 and 2 e) 2 and 3 Answer: a Difficulty: Medium

Learning Objective: LO 2.3 Describe the role of noncovalent bonds in the structure of molecules such as water.

Section Reference: Section 2.3 Noncovalent Bonds

18) In a cell, where are strong ionic bonds most likely to be found? a) in the cytoplasm b) between DNA strands c) deep in a protein's core where water is excluded d) on the surface of a protein e) on the surface of a lipid Answer: c Difficulty: Medium

Learning Objective: LO 2.3 Describe the role of noncovalent bonds in the structure of molecules such as water.

Section Reference: Section 2.3 Noncovalent Bonds

19) Which interaction is most important in enhancing the solubility of macromolecules in water? a) hydrophobic interactions b) nonpolar covalent bonds c) hydrogen bonds d) van der Waals forces

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e) Both hydrophobic interactions and nonpolar covalent bonds Answer: c Difficulty: Hard

Learning Objective: LO 2.3 Describe the role of noncovalent bonds in the structure of molecules such as water.

Section Reference: Section 2.3 Noncovalent Bonds

20) Where are hydrophobic interactions most likely to occur? a) on the surface of a water-soluble protein b) the core of a water-soluble protein c) in contact with water molecules d) between two charged molecules e) between two ions Answer: b Difficulty: Medium

Learning Objective: LO 2.3 Describe the role of noncovalent bonds in the structure of molecules such as water.

Section Reference: Section 2.3 Noncovalent Bonds

21) What kind of noncovalent interaction is typified by interactions between two molecules that are so close together that they can experience weak attractive forces bonding them together? a) hydrogen bond b) ionic bond c) hydrophobic interaction d) polar covalent bond e) van der Waals forces Answer: e Difficulty: Easy

Learning Objective: LO 2.3 Describe the role of noncovalent bonds in the structure of molecules such as water.

Section Reference: Section 2.3 Noncovalent Bonds

22) Chemists describe ionic bonds as strong bonds while cell biologists consider them relatively weak bonds. This can be explained due to the fact that: a) chemists are usually considering free ionic bonds between charged atoms.

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b) cell biologists are usually comparing ionic bonds to much stronger hydrogen bonds. c) chemists examine ionic bonds only in the context of an aqueous cellular environment. d) cell biologists overlook the role of water in reducing the strength of ionic bonds.

Answer: a Difficulty: Medium

Learning Objective: LO 2.3 Describe the role of noncovalent bonds in the structure of molecules such as water.

Section Reference: Section 2.3 Noncovalent Bonds

23) Van der Waals forces are the result of: a) ionic attractions b) hydrophilic molecular attractions to one another c) aggregation to exclude water from hydrophobic molecular faces d) transient asymmetric electron density shifts Answer: d Difficulty: Medium

Learning Objective: LO 2.3 Describe the role of noncovalent bonds in the structure of molecules such as water.

Section Reference: Section 2.3 Noncovalent Bonds

24) The optimal interatomic distance for strong Van der Waals interactions between atoms of two molecules is about: a) 1 angstrom b) 2 angstroms c) 4 angstroms d) greater than 8 angstroms Answer: c Difficulty: Easy

Learning Objective: LO 2.3 Describe the role of noncovalent bonds in the structure of molecules such as water.

Section Reference: Section 2.3 Noncovalent Bonds

25) Water’s life-supporting properties include all of the following EXCEPT:

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a) high boiling point compatible with temperate extremes of summer allowing energy to be released through sweat b) protection from cold and damaging radiation by providing the matrix around which the cellular framework is constructed. c) high probability of bonding with nonpolar molecules d) ability to dissociate into OH- and H+ units within the cell Answer: c Difficulty: Easy

Learning Objective: LO 2.3 Describe the role of noncovalent bonds in the structure of molecules such as water.

Section Reference: Section 2.3 Noncovalent Bonds

26) A molecule that is capable of releasing or donating a hydrogen ion is termed _______. a) a base b) a hydrion c) an acid d) an anachronism e) an amphipath Answer: c Difficulty: Easy

Learning Objective: LO 2.4 Explain the characteristics of acids, bases, and buffers.

Section Reference: Section 2.4 Acids, Bases, and Buffers

27) A release of hydrogen ions to a solution would most likely ____________. a) raise pH b) lower pH c) buffer pH d) change salinity e) not affect pH Answer: b Difficulty: Easy

Learning Objective: LO 2.4 Explain the characteristics of acids, bases, and buffers.

Section Reference: Section 2.4 Acids, Bases, and Buffers

28) Reactions in which a proton may participate include:

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a) formation of an amine group by combining with a sugar hydroxyl group b) formation of an amine group by combining with a hydronium ion c) formation of water by combining with a sugar hydroxyl group d) formation of water by combining with a free hydroxyl group Answer: d Difficulty: Medium

Learning Objective: LO 2.4 Explain the characteristics of acids, bases, and buffers.

Section Reference: Section 2.4 Acids, Bases, and Buffers

29) A pH shift from 4 to 7 creates a solution which is a) 100 times more acidic b) 1000 times more basic c) 3 times more acidic d) 300 times more basic Answer: b Difficulty: Medium

Learning Objective: LO 2.4 Explain the characteristics of acids, bases, and buffers.

Section Reference: Section 2.4 Acids, Bases, and Buffers

30) A pH shift from 10 to 8 creates a solution which is a) 100 times more acidic b) 1000 times more basic c) 2 times more acidic d) 200 times more basic Answer: a Difficulty: Medium

Learning Objective: LO 2.4 Explain the characteristics of acids, bases, and buffers.

Section Reference: Section 2.4 Acids, Bases, and Buffers

31) A buffer has all of the following characteristics EXCEPT: a) the ability to protect cells from fluctuations in pH b) the ability to protect cells from fluctuations in temperature c) able to react with hydrogen ions d) able to react with hydroxyl ions

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Answer: b Difficulty: Medium

Learning Objective: LO 2.4 Explain the characteristics of acids, bases, and buffers.

Section Reference: Section 2.4 Acids, Bases, and Buffers

32) The main buffer system operating to maintain stable blood pH is made up of: a) Carbonic acid/bicarbonate ions b) H2PO4-/HPO42c) acetate/acetic acid d) chloride ions/ HCl Answer: a Difficulty: Easy

Learning Objective: LO 2.4 Explain the characteristics of acids, bases, and buffers.

Section Reference: Section 2.4 Acids, Bases, and Buffers

33) Hyperventilation can create the potential for blood pH to rise to a harmful level. Why are hyperventilating individuals suffering from panic attacks advised to breathe in and out from within a paper bag? a) the bag increases the air pressure, allowing more hydrogen ions to dissolve in the blood b) the additional CO2 combines with water to produce carbonic acid, which, in turn dissociates to bicarbonate and protons, thereby lowering pH c) the additional CO2 combines with water to produce bicarbonate, which, in turn dissociates to carbonic acid and protons, thereby lowering pH d) the additional CO2 combines with water to produce carbonic acid, which, in turn dissociates to bicarbonate and protons, thereby raising pH Answer: b Difficulty: Hard

Learning Objective: LO 2.4 Explain the characteristics of acids, bases, and buffers.

Section Reference: Section 2.4 Acids, Bases, and Buffers

34) At higher proton concentrations, proteins are likely to possess: a) more NH2 groups and more NH3+ groups b) fewer NH2 groups and fewer NH3+ groups c) more NH2 groups and fewer NH3+ groups

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d) fewer NH2 groups and more NH3+ groups Answer: d Difficulty: Easy

Learning Objective: LO 2.4 Explain the characteristics of acids, bases, and buffers.

Section Reference: Section 2.4 Acids, Bases, and Buffers

35) If you want a solution which is basic to be neutralized by adding the smallest volume of an acid as possible, which of these choices would you use? a) acetic acid b) carbonic acid c) hydrochloric acid d) water Answer: c Difficulty: Medium

Learning Objective: LO 2.4 Explain the characteristics of acids, bases, and buffers.

Section Reference: Section 2.4 Acids, Bases, and Buffers

36) The low-molecular-weight building blocks of polymers are called _______. a) minipolymers b) monoblocks c) monomers d) portions e) octamers Answer: c Difficulty: Easy

Learning Objective: LO 2.5 Describe the general structure and functions of biological molecules.

Section Reference: Section 2.5 The Nature of Biological Molecules

37) Why is silicon not suitable for making covalent bonds stable and strong enough to form the basis of living organisms, even though it is just below carbon on the periodic table? a) Silicon is too large for its nucleus to attract the valence electrons of neighboring atoms in order to form covalent bonds. b) Silicon is too small for its nucleus to attract the valence electrons of neighboring atoms in order to form covalent bonds.

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c) Silicon is too large for its nucleus to attract the protons of neighboring atoms in order to form covalent bonds. d) Silicon is too small for its nucleus to attract the protons of neighboring atoms in order to form covalent bonds.

Answer: a Difficulty: Hard

Learning Objective: LO 2.5 Describe the general structure and functions of biological molecules.

Section Reference: Section 2.5 The Nature of Biological Molecules

38) Which of the following is NOT a macromolecule formed by polymerization? a) proteins b) lipids c) polynucleotides d) polysaccharides e) DNA Answer: b Difficulty: Medium

Learning Objective: LO 2.5 Describe the general structure and functions of biological molecules.

Section Reference: Section 2.5 The Nature of Biological Molecules

39) Which of the following tripeptides would be most likely to be soluble in an organic (hydrophobic) solvent like benzene? a) N - phenylalanine - alanine - glycine – C b) N - leucine - alanine - lysine - C c) N - proline - phenylalanine - leucine - C d) N - arginine - lysine - proline - C e) N - glutamate - aspartate - glycine – C Answer: c Difficulty: Hard

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

40) Organic molecules are currently defined by which characteristic? a) derived from a living organism

Page 14

b) based on C-C bonds c) possessing C-O bonds d) containing C-H bonds Answer: b Difficulty: Easy

Learning Objective: LO2.5 Describe the general structure and functions of biological molecules.

Section Reference: Section 2.5 The Nature of Biological Molecules

41) The historic meaning of an organic molecule was that the molecule was derived from a living organism and contained carbon. Today we call such molecules __________________. a) inorganics b) polymers c) biochemicals d) cyclic Answer: c Difficulty: Easy

Learning Objective: LO2.5 Describe the general structure and functions of biological molecules.

Section Reference: Section 2.5 The Nature of Biological Molecules

42) Carbon’s suitability as the molecular framework for biochemicals stems from its: a) large nucleus containing a high ratio of neutrons b) almost full outer shell of electrons, allowing for the formation of linear, branched and cyclic molecules c) ability to form elongated polymers d) high electronegativity Answer: c Difficulty: Medium

Learning Objective: LO2.5 Describe the general structure and functions of biological molecules.

Section Reference: Section 2.5 The Nature of Biological Molecules

43) Which of these functional groups is the LEAST polar? Refer to Table 2.2 in the text for more information if you are uncertain of the molecular structure of each one. a) CH3 b) OH c) COOH d) SH

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Answer: a Difficulty: Medium

Learning Objective: LO2.5 Describe the general structure and functions of biological molecules.

Section Reference: Section 2.5 The Nature of Biological Molecules

44) Select the order in which you might expect molecules involved in the synthesis of a polymer to be present as a cell grows. a) precursor, metabolic intermediate, miscellaneous molecule b) metabolic intermediate, miscellaneous molecule, macromolecule c) precursor, metabolic intermediate, macromolecule d) macromolecule, precursor, miscellaneous molecule Answer: c Difficulty: Easy

Learning Objective: LO2.5 Describe the general structure and functions of biological molecules.

Section Reference: Section 2.5 The Nature of Biological Molecules

45) Which organism would be a good candidate for researching genes related to nitrogen fixation? a) rhizobia b) algae c) leguminous plants d) non-leguminous plants Answer: d Difficulty: Medium

Learning Objective: LO 2.6 Identify the chemicals in fertilizer that are crucial to plant growth.

Section Reference: Section 2.6 Green Cells: Chemical Fertilizers

46) Which element can only be obtained by plants through mineral uptake, rather than via atmospheric fixation by the plant or its symbiont? a) phosphorus b) carbon c) nitrogen

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d) oxygen Answer: a Difficulty: Easy

Learning Objective: LO 2.6 Identify the chemicals in fertilizer that are crucial to plant growth.

Section Reference: Section 2.6 Green Cells: Chemical Fertilizers

47) Which group of plants have nitrogen fixing symbionts? a) monocots b) dicots c) legumes d) rhizobia e) bacteroids Answer: c Difficulty: Easy

Learning Objective: LO 2.6 Identify the chemicals in fertilizer that are crucial to plant growth.

Section Reference: Section 2.6 Green Cells: Chemical Fertilizers

48) The endosymbiotic theory proposes that bacteria were engulfed by ancestral eukaryotic cells and sheltered within their cytoplasm whilst providing a survival advantage to the eukaryotic cell as well.

Mitochondria and chloroplasts, now organelles, possess DNA with sequence homology to rickettsia and cyanobacteria, respectively. Which of the choices below best describes an organelle-like structure with a similar beneficial relationship when considering plant growth in nitrogen-limited soils? a) rhizobia b) bacteroids c) legumes d) cyanobacteria e) all are possible correct choices Answer: b Difficulty: Hard

Learning Objective: LO 2.6 Identify the chemicals in fertilizer that are crucial to plant growth.

Section Reference: Section 2.6 Green Cells: Chemical Fertilizers

49) What bond is responsible for the branch points in glycogen and amylopectin? a) a(1—>4) glycosidic linkages b) b(1—>4) glycosidic linkages Page 17

c) a(1—>6) glycosidic linkages d) b(1—>6) glycosidic linkages e) 3'-5' phosphodiester linkages Answer: c Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

50) Which polysaccharide bond cannot be broken by mammalian enzymes that normally digest polysaccharides? a) a(1—>4) glycosidic linkages b) b(1—>4) glycosidic linkages c) a(1—>6) glycosidic linkages d) b(1—>6) glycosidic linkages e) phosphate ester linkages Answer: b Difficulty: Hard

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

51) Why do sugars tend to be highly water soluble? a) they have only a few hydroxyl groups b) they have large numbers of hydroxyl groups c) they have large numbers of sulfhydryl groups d) they have large numbers of methyl groups e) they have small molecular weights Answer: b Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

52) If a polypeptide is 100 amino acids long, and could be made of any of the 20 amino acids in any

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order, what is the total number of possible variations for this polypetide? a) 10020 b) 2,000 c) 20100 d) 20101 e) 20 Answer: c Difficulty: Hard

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

53) How do amino acids like hydroxylysine and thyroxine, which are not among the 20 amino acids inserted into amino acid chains, get into proteins? a) They are inserted due to mutations. b) They are the result of the alteration of R groups of the 20 amino acids after their incorporation into the polypeptide. c) They occur as carboxyl groups are altered, reversing the chirality of the molecules. d) Insertion of the amino acid into the polypeptide causes bonds to break and new amino acids to form.

Answer: b Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules 54) Which of these amino acids is most likely to be found in the core of a protein? a) methionine b) asparagine c) serine d) threonine e) glutamic acid Answer: a Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

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55) What type of protein secondary structure is characterized as being highly extensible because of its coiled structure? a) b-pleated sheet b) proline kink c) a-helix d) globular Answer: c Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

56) The b-pleated sheet is characterized by the orientation of ______ to the molecular axis. a) H bonds parallel b) H bonds perpendicular c) ionic bonds parallel d) ionic bonds perpendicular e) peptide bonds perpendicular Answer: b Difficulty: Easy

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

57) Proteins are often composed of two or more distinct modules that fold up independently of one another. They often represent parts of a protein that function in a semi-independent manner. These modules are called ______. a) protein motifs b) functionals c) domains d) dominoes Answer: c Difficulty: Easy

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

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58) What level of structure in proteins is held together by R group interactions between different polypeptides? a) primary structure b) secondary structure c) tertiary structure d) quaternary structure Answer: d Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

59) Which of the following is a nucleotide? a) phosphate + ribose + deoxyribose b) adenine + deoxyribose c) sugar + nitrogenous base d) adenine + ribose + phosphate Answer: d Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

60) An informative test for the diagnosis of diabetes is to monitor levels of Hemoglobin A1c, produced through the reaction of hemoglobin and __________________. a) the linear aldose form of glucose b) the cyclic isoform of glucose c) the chair form of glucose d) the Haworth projection form of glucose Answer: a Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

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61) Which of these statements regarding glyceraldehyde is NOT correct? a) glyceraldehyde stereoisomers exhibit optical activity by rotating plane-polarized light in opposite directions b) glyceraldehyde stereoisomers cannot be superimposed on one another c) glyceraldehyde is one of several three-carbon aldoses d) glyceraldehyde’s second carbon is covalently bound to H, OH, CHO and COOH groups Answer: c Difficulty: Hard

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

62) Fatty acids with a polar carboxyl group and a nonpolar hydrocarbon chain are considered ___________________ molecules. a) entirely hydrophobic b) entirely hydrophilic c) amphipathic d) non-reactive Answer: c Difficulty: Easy

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

63) Examine the structures of cholesterol, testosterone and estrogen shown in Figure 2.23 in the text (Or provide the figure for the Q). If we know that cholesterol is the precursor for synthesizing the other sex hormones, which of the statements below is likely to be CORRECT? a) cholesterol will require demethylation to be converted into testosterone but not to be converted into estrogen b) cholesterol will require demethylation to be converted into both testosterone and estrogen c) cholesterol will require demethylation to be converted into estrogen but not to be converted into testosterone d) all statements are incorrect Answer: b

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Difficulty: Hard

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

64) In a phospholipid, the end of the molecule likely to face towards a nonpolar environment is ________________. a) the end with the choline group b) the end with the phosphate group c) the region with the glycerol backbone d) the end with the fatty acid chains Answer: d Difficulty: Easy

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

65) Which lipid is most likely to remain solid at room temperature? a) tristearate b) vegetable oil c) polyunsaturated fat d) linseed oil Answer: a Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

66) You discover a novel protozoan which seems able to exist in the extreme salinity of the Dead Sea. Comparative examination of its enzyme structures against those of non-halophilic protozoa are most likely to reveal that ________________. a) the novel protozoan possesses enzymes where the outer protein surface has many acidic amino acid residues b) the novel protozoan possesses enzymes where the outer protein surface has many nonpolar amino acid residues c) the novel protozoan possesses enzymes where the outer protein surface has many cysteine-associated disulfide bridges

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d) all are equally likely possibilities Answer: a Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

67) Not all proteins are able to renature. When exposed to heat or some other denaturing treatment , some proteins are irreversibly denatured, while others can renature when the denaturant is removed. What is an example of a protein demonstrated to refold correctly? a) hemoglobin b) urease c) egg yolk protein d) ribonuclease A Answer: d Difficulty: Easy

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

68) You are working with an enzyme altase that you denature in the presence of urea. If altase were denatured no further by the addition of mercaptoethanol, what would that suggest to you about the enzyme? a) The enzyme probably contained no positively charged amino acids since these are neutralized by mercaptoethanol. b) The enzyme probably contained no acidic amino acids since these are neutralized by mercaptoethanol. c) The enzyme probably contained no disulfide linkages since mercaptoethanol breaks such linkages. d) Mercaptoethanol and urea denature enzymes in the same manner, so the observation lacks significance.

Answer: c Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

69) Many so-called temperature-sensitive mutations have been discovered in a wide variety of organisms.

These are proteins that are non-functional at higher temperatures, while, at lower temperatures (often just

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a few degrees lower), they function normally. For example, the coloration patterns in Siamese Cats arise from a temperature-sensitive mutation. An enzyme required for the synthesis of dark pigment is unable to function in areas close to the body where normal physiological temperatures prevail. However, at the tips of the ears, paws, the tip of the tail and other extremities where the temperature is slightly lower, the enzyme works correctly and dark pigment is produced. What is happening at the molecular level that explains this? a) the enzyme responsible for pigment production is more sensitive to cold than others in the animal cells and unfolds in the cooler environment of the extremities b) the enzyme responsible for pigment production is more sensitive to heat than others in the animal cells and unfoldsin the cooler environment of the extremities c) the enzyme responsible for pigment production is more sensitive to cold than others in the animal cells and maintains activity in the cooler environment of the extremities d) the enzyme responsible for pigment production is more sensitive to heat than others in the animal cells and maintains activity in the cooler environment of the extremities Answer: d Difficulty: Easy

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

70) You are studying a protein. It binds to elongating polypeptide chains as they emerge from an exit channel within the ribosome's large subunit. It appears to prevent partially formed or nascent polypeptides from binding to other proteins in the cytosol, which might cause them either to aggregate or misfold.

What kind of proteins is this likely to be? a) Hsp70 chaperone b) TRiC chaperonin c) heat shock protein d) ribosomal protein Answer: a Difficulty: Easy

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

71) It is thought that most human diseases leave telltale patterns among the thousands of proteins present in the blood or other bodily fluids. It was hoped that analysis of the proteins present in the blood would help in the diagnosis of human disease; however, thus far, searches for these proteins in blood or bodily fluids have been largely unsuccessful and their use in diagnostics largely unreliable. What are these telltale patterns of proteins called?

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a) chaperonins b) biomarkers c) proteomes d) peptide mass fingerprints Answer: b Difficulty: Easy

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

72) TAP-tag mass spectrometry is a technique employed in the field of science best described as: a) genomics b) proteomics c) interactomics d) lipidomics Answer: c Difficulty: Easy

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

73) The nucleic acid precursor comprising one nitrogenous base and one sugar is known as a: a) nucleoside b) nucleotide c) pyrimidine d) purine Answer: a Difficulty: Easy

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

74) A single-ringed nitrogenous base found in nucleic acid precursors is termed a ___________________. a) nucleoside

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b) nucleotide c) pyrimidine d) purine Answer: c Difficulty: Easy

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

75) Which of the following experimental assemblies provides the LEAST compelling evidence that life processes are often self-directed? a) The 1955 observation that tobacco mosaic virus spontaneously assembles. b) Nomura’s 1960’s experiment demonstrated spontaneous assembly of a bacterial 30S ribosomal unit from 21 purified proteins and ribosomal RNA. c) Removal of protein S16 from the bacterial 30S ribosomal protein/RNA mix in Nomura’s experiment prevented self-assembly, providing evidence that the assembly is self-directed and sequential steps are essential. d) Bacterial ribosome assembly is achieved inside cells in as little as 10 minutes, while in vitro 2 hours at elevated temperatures is required.

Answer: d Difficulty: Easy

Learning Objective: LO 2.8 Analyze the evidence supporting the idea that bacterial ribosomal subunits are capable of self-assembly.

Section Reference: Section 2.8 The Formation of Complex Macromolecular Structures

76) The process by which proteins and RNA form in an elastic conformation is known as: a) aqueous phase separation b) gelation c) intrinsically disordered domain formation d) intrinsically organized domain formation Answer: b Difficulty: Easy

Learning Objective: LO 2.8 Analyze the evidence supporting the idea that bacterial ribosomal subunits are capable of self-assembly.

Section Reference: Section 2.8 The Formation of Complex Macromolecular Structures

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Question Type: Multiple Select

77) Which of these functional groups would make a biochemical more soluble in water? (Select all that apply) a) CH3 b) OH c) COOH d) SH Answer: b, c, d Difficulty: Medium

Learning Objective: LO2.5 Describe the general structure and functions of biological molecules.

Section Reference: Section 2.5 The Nature of Biological Molecules

Question Type: Multiple Select

78) Biological roles for carbohydrates include: (Select all that apply) a) structural molecules b) catalytic molecules c) energy storage molecules d) repositories of genetic information Answer: a, b Difficulty: Easy

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

Question Type: Multiple Select

79) Select the correct statements regarding carbohydrate structure: (Select all that apply) a) If the carbonyl group of a sugar has an internal placing, the sugar is termed a ketose, such as glucose. b) If the carbonyl group of a sugar has an internal placing, the sugar is termed a ketose, such as fructose. c) If the carbonyl group of a sugar has a terminal placing, the sugar is termed an aldose, such as glucose. d) If the carbonyl group of a sugar has a terminal placing, the sugar is termed an aldose, such as fructose.

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Answer: b, c Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

Question Type: Multiple Select

80) Select the durable structural polysaccharides from the choices provided. (Select all that apply) a) glucose b) starch c) cellulose d) chitin e) glycosaminoglycan Answer: c, d Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

Question Type: Multiple Select

81) If an organism lives in an environment where significant temperature fluctuations occur, and is capable of altering the fatty acid composition of its phospholipid bilayer, which of these choices would best allow membrane integrity to remain stable? (Select all that apply) a) increasing stearic acid incorporation during cold weather b) decreasing stearic acid incorporation during cold weather c) increasing stearic acid incorporation during hot weather d) decreasing stearic acid incorporation during hot weather Answer: b, c Difficulty: Hard

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

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Section Reference: Section 2.7 Four Types of Biological Molecules

Question Type: Multiple Select

82) You treat a partially purified preparation of protein with a reagent that breaks bonds between sulfur atoms. Which level(s) of protein structure are most likely to be affected? (Select all that apply) a) primary b) secondary c) tertiary d) quaternary Answer: c, d Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

Question Type: Multiple Select

83) Which statements regarding mad cow disease and Alzheimer’s disease are CORRECT? (Select all that apply) a) Both diseases are characterized by the presence of large quantities of misfolded PrPc b) Both are fatal neurodegenerative diseases c) Fibrillar insoluble protein complexes known as amyloid deposits are found in both diseases d) The same brain regions are affected in both diseases Answer: b, c Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

Question Type: Multiple Select

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84) RNA and DNA NEVER differ in the functional groups attached to: (Select all that apply) a) the 1’ carbon b) the 3’ carbon c) the 2’ carbon d) the 5’carbon Answer: b, d Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

Question Type: Multiple Select

85) RNA and DNA ALWAYS differ in the functional groups attached to: (Select all that apply) a) the 1’ carbon b) the 3’ carbon c) the 2’ carbon d) the 5’carbon Answer: c Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

Question Type: Multiple Select

86) Roles for nucleotide monomers include: (Select all that apply) a) acting catalytically to splice RNA b) playing a role in energy provision for cellular reactions c) serving as building blocks for DNA synthesis d) serving as building blocks for protein synthesis Answer: b, c

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Difficulty: Medium

Learning Objective: LO 2.7 Identify the monomers, the synthesis, and the functions in the cell of the four types of biological molecules.

Section Reference: Section 2.7 Four Types of Biological Molecules

Question Type: Multiple Select

87) Which of these factors or observations provide explanations of how the self-assembly of complex structures such as ribosomal subunits can be achieved more efficiently within cells than in vitro? (Select all that apply) a) prokaryotic cells have been seen to require the participation of transiently associated proteins b) aqueous phase separation occurs in vivo, but not in vitro c) many proteins associated with RNA readily form cytoplasmic phase-separated droplets within cytoplasm d) Rbfox’s intrinsically disordered domain appears crucial for both aqueous phase separation and RNA splicing function.

Answer: b, c, d Difficulty: Hard

Learning Objective: LO 2.8 Analyze the evidence supporting the idea that bacterial ribosomal subunits are capable of self-assembly.

Section Reference: Section 2.8 The Formation of Complex Macromolecular Structures

Question Type: Multiple Select

88) Which of these molecules have been observed to play a role in eukaryotic RNA/protein interaction where aqueous phase separation is being studied? (Select all that apply) a) S16 b) chaperone-like proteins c) FUS d) Whi3 Answer: c, d Difficulty: Medium

Learning Objective: LO 2.8 Analyze the evidence supporting the idea that bacterial ribosomal subunits are capable of self-assembly.

Section Reference: Section 2.8 The Formation of Complex Macromolecular Structures

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Package Title: Test Bank Course Title: Karp9e Chapter Number: 3 Question Type: Multiple Choice

1) The chemical energy stored in ATP is converted to mechanical energy that can move organelles around within the cell. This is an example of __________. a) being exothermic b) being endothermic c) energy transduction d) polymerization e) catheterization Answer: c Difficulty: Medium Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

2) When energy is being stored for later use or for use at a distant site, the most frequent form of storage is _____________________. a) as mechanical energy b) within the chemical bonds of molecules c) as kinetic energy d) as electrostatic energy Answer: b Difficulty: Medium Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

3) What is an essential difference between thermodynamics and bioenergetics?

a) Bioenergetics studies energy transformations taking place within living organisms while thermodynamics studies energy changes within a broader system, up to the size of the universe. b) Bioenergetics studies energy transformations taking place within living organisms while thermodynamics studies molecular reactions occurring in isolation. c) Thermodynamics studies energy transformations taking place within living organisms while bioenergetics studies energy changes within a broader system, up to the size of the universe. d) Bioenergetics studies energy transformations taking place within living organisms while thermodynamics studies only the energy changes of the non-living world.

Answer: a Difficulty: Medium Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

4) The first law of thermodynamics states that ________________: a) energy can be created and transduced from one form to another b) energy can be destroyed and can be transduced from one form to another c) energy cannot be created or destroyed and cannot be transduced from one form to another d) energy cannot be created or destroyed but can be transduced from one form to another Answer: d Difficulty: Easy Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

5) You are observing a reaction and discover that the reaction vessel is warm to the touch. The reaction also results in an increase in entropy. Which statement correctly confirms whether or not the reaction is spontaneous and explains why? a) The reaction is exothermic (-DH) as demonstrated by the warm reaction vessel and entropy is increased (+DS). The reaction has a negative DG and is, therefore, spontaneous. b) The reaction is exothermic (+DH) as demonstrated by the warm reaction vessel and entropy is increased (+DS). The reaction therefore has a negative DG and is, therefore, spontaneous. c) The reaction is exothermic (+DH) as demonstrated by the warm reaction vessel and entropy is increased (-DS). The reaction has a positive DG and is, therefore, spontaneous. d) The reaction is endothermic (-DH) as demonstrated by the warm reaction vessel and entropy is increased (-DS). The reaction has a positive DG and is, therefore, spontaneous.

Answer: a Difficulty: Hard Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

6) A reaction vessel is cold to the touch and the reaction results in an increase in order of the products inside the reaction vessel. Which statement correctly confirms whether or not the reaction is spontaneous and explains why? a) The reaction is exothermic (-DH) as demonstrated by the cold reaction vessel and entropy is increased (+DS). The reaction has a negative DG and is, therefore, spontaneous. b) The reaction is endothermic (+DH) as demonstrated by the cold reaction vessel and entropy is decreased (-DS). The reaction therefore has a positive DG and is, therefore nonspontaneous. c) The reaction is exothermic (+DH) as demonstrated by the cold reaction vessel and entropy is increased (-DS). The reaction has a positive DG and is, therefore, spontaneous. d) The reaction is endothermic (-DH) as demonstrated by the cold reaction vessel and entropy is increased (+DS). The reaction has a positive DG and is, therefore, nonspontaneous.

Answer: b Difficulty: Hard Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

7) Which of the equation sets represents coupled reactions? a) A + B --> C + D (DG = -5.4 kcal/mole) and E + F --> G + H (DG = +4.4 kcal/mole) b) A + B --> C + D (DG = -5.4 kcal/mole) and C + D --> E + F (DG = +4.4 kcal/mole) c) A + B --> C + D (DG = -5.4 kcal/mole) and E + F --> C + D (DG = +4.4 kcal/mole) d) all are correct examples of coupled reactions Answer: b Difficulty: Medium Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

8) Which choice below correctly rationalized whether this pair of reactions is coupled?

A + B --> C + D (DG = +5.4 kcal/mole) D + F --> G + H (DG = -4.4 kcal/mole) a) The equations above do not represent coupled reactions because the overall DG is positive. b) The equations above do not represent coupled reactions because the overall DG is negative. c) The equations represent coupled reactions because the overall DG is positive. d) The equations represent coupled reactions because the overall DG is negative.

Answer: a Difficulty: Medium Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

9) Reactions that lose heat are termed: a) entropic b) endothermic c) exothermic d) unreactive Answer: c Difficulty: Easy Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

10) The statement that events in the universe proceed from a state of higher energy to one of lower energy describes the_____________________. a) first law of thermodynamics b) second law of thermodynamics c) third law of thermodynamics d) fourth law of thermodynamics Answer: b

Difficulty: Easy Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

11) Which scenario does NOT describe an increase in entropy within the system described? a) dissolving table salt in warm water b) running a steam engine on a cold day c) observing an ice cube on a hot summer’s day d) observing an ice cube at absolute 0 K Answer: d Difficulty: Easy Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

12) Entropy is associated with the _________ movement of particles of matter, which because they are ________ cannot accomplish a directed work process. a) rapid, directed b) random, random c) rapid, random d) slow, rapid e) random, slow Answer: b Difficulty: Easy Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

13) Enthalpy is ________. a) the energy available to do work b) the total energy content of a system

c) named after J. Willard Gibbs d) the energy available to do work and the total energy content of a system e) All of these are correct.

Answer: b Difficulty: Easy Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

14) Given the equation DG = DH - TDS, which set of conditions would result in a reaction that is unambiguously nonspontaneous? a) entropy decreases and the reaction is endothermic b) entropy increases and the reaction is exothermic c) entropy stays the same and there is no change in enthalpy d) entropy decreases and the reaction is exothermic e) entropy increases and the reaction is endothermic Answer: a Difficulty: Hard Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

15) Which reaction below might be a suitable coupled reaction for the reaction A + B —> C + D (DG = -8.7 kcal/mole)? a) E + F —> G + H (DG = -5.4 kcal/mole) b) B + F —> G + H (DG = -5.4 kcal/mole) c) C + F —> G + H (DG = +8.3 kcal/mole) d) C + F —> G + H (DG = +9.7 kcal/mole) e) A + F —> G + H (DG = +10.2 kcal/mole) Answer: c Difficulty: Hard Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

16) What kind of organism reaches equilibrium? a) one that is actively metabolizing b) one with a low metabolic rate c) a dead organism d) a eukaryote e) a prokaryote Answer: c Difficulty: Easy Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

17) You mix reagents (A, B, C, D) so that each is present at an initial concentration of 0.5M. The equilibrium constant for the reaction Keq is 4. Which choice represents the final concentrations of each reagent

once equilibrium is achieved? [

a) [ 0.67][0.67] [ 0.33][0.33] b) [ 0.5][0.5] [ 0.25][0.25 ] c) [ 0.4][0.4] [ 0.5][0.5] d) [ 0.4][0.4] [ 0.1][0.1] Answer: a Difficulty: Hard Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

18) After allowing the reaction to proceed, you find that the the final concentrations of each reagent

once equilibrium is achieved is [0.3][0.3]

]

[0.7][0.7]

What is the value of the equilibrium constant Keq? a) 18 b) 1.8 c) 0.18 d) .001 Answer: c Difficulty: Medium Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

19) After allowing the reaction to proceed, you find that the the final concentrations of each once equilibrium is achieved is [0.35][0.35] [0.65][0.65]

Will the reaction proceed in a forward manner, namely with production of increased concentrations of products? a) yes, because Keq is greater than 1 b) no, because Keq is greater than 1 c) yes, because Keq is less than 1 d) no, because Keq is less than 1 Answer: d Difficulty: Medium Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

20) A pharmacist is looking for a drug which will prevent an enzyme from working by binding to it as an inhibitor. Which of the inhibitors listed as choices will prove most effective, given equality in other considerations such as solubility, toxicity and stability? a) Substance X, Kd = 2.7 b) Substance Y, Kd = 23

c) Substance Z, Kd = 0.05 d) Substance P, Kd = 0.001 Answer: d Difficulty: Medium Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1: Bioenergetics

21) Which property below is NOT a characteristic of enzymes? a) They are only effective in high concentrations. b) They are altered reversibly during a reaction. c) They do not alter the ΔG of a reaction. d) They are used over and over again. e) They do not determine whether a reaction is exergonic or endergonic.

Answer: a Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

22) Enzymes work by ___________. a) raising the activation energy of a reaction and thus speeding up the reaction b) lowering the activation energy of a reaction and thus speeding up the reaction c) raising the DG of a reaction and thus speeding up the reaction d) lowering the DG of a reaction and thus speeding up the reaction e) changing the free energy of the products and thus speeding up the reaction Answer: b Difficulty: Easy Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

23) What kind of interaction is NOT involved in the binding of a substrate to a normally functioning enzyme? a) hydrogen bonds b) a transient covalent bond c) ionic bonds d) a permanent covalent bond e) hydrophobic interactions Answer: d Difficulty: Easy Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

24) What molecule type other than protein has been observed to have catalytic activity? a) carbohydrates b) lipids c) RNA d) DNA Answer: c Difficulty: Easy Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

25) Who was the first scientist to determine the structure and composition of an enzyme? a) von Liebig b) Pasteur c) Sumner d) Büchner Answer: c Difficulty: Easy Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

26) In the absence of an enzyme, a monosaccharide like galactose or glucose, will likely decompose in roughly ___________. a) 30 seconds b) 3 weeks c) 30 days d) 30,000 years Answer: d Difficulty: Easy Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

27) Energy rich monosaccharides and other biological monomers which are seen to exist stably in purified form are said to be: a) neither thermodynamically nor kinetically stable b) both thermodynamically and kinetically stable c) thermodynamically stable but kinetically unstable d) thermodynamically unstable but kinetically stable Answer: d Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

28) You are a researcher trying to design an enzyme inhibitor for a particular enzyme. Which molecule should your inhibitor most closely resemble for the most effective inhibition to take place? a) the enzyme’s final product b) the enzyme’s initial substrate c) the transition state intermediate produced during enzyme-substrate interaction d) the transition state intermediate produced during enzyme-product release

Answer: c Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

29) The environment within an enzyme’s active site tends to have ______________ characteristics. a) acidic b) hydrophilic c) basic d) hydrophobic Answer: c Difficulty: Easy Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

30) Doubling the concentration of enzyme will ______ the Vmax and _____ the KM. a) double, not alter b) not alter, double c) double, double d) not change, not alter e) halve, halve Answer: a Difficulty: Hard Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

31) What kind of inhibitor binds very tightly to an enzyme often forming a covalent bond with an amino acid in the active site?

a) irreversible b) reversible c) uncompetitive d) reversible and uncompetitive e) None of these are correct.

Answer: a Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

32) The effect of a competitive inhibitor can be reversed by _______. a) increasing inhibitor concentration b) increasing substrate concentration c) heating the reaction mixture d) changing the pH e) massaging the enzyme Answer: b Difficulty: Easy Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

33) You are observing an enzyme driven reaction. You add chemical X, which inhibits the reaction. If you add more substrate, the reaction rate approaches the Vmax of the uninhibited reaction. Furthermore, the structure of X is similar to the natural substrate. What kind of inhibitor is X? a) irreversible b) reversible c) competitive d) reversible and uncompetitive e) None of these are correct.

Answer: c

Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

34) What is the effect of a competitive inhibitor on an enzyme-mediated reaction? a) Vmax stays the same, KM decreases b) Vmax decreases, KM is unchanged c) Vmax increases, KM is unchanged d) Vmax stays the same, KM is unchanged e) Vmax stays the same, KM increases Answer: e Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

35) The existence of ________ motion in proteins suggests that enzymes are capable - even in the absence of substrate - of many of the same movements that can be detected during their catalytic cycle. a) extrinsic b) intrinsic c) instant d) built-in e) intrinsic and built-in Answer: e Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

36) In the reaction A + B <—> C + D, how might the reaction take place in the cell if the DG is very positive?

a) The reaction would probably take place by coupling it to a reaction with a larger -DG so that when the DG values are added up the sum is negative. b) The reaction would probably take place by coupling it to a reaction with a smaller -DG so that when the DG values are added up the sum is positive. c) The reaction would probably take place by coupling it to a reaction with a larger DG so that when the DG values are added up the sum is positive. d) The reaction would probably take place by coupling it to a reaction with the same positive DG so that when the DG values are added up the energy levels balance.

Answer: a Difficulty: Medium Learning Objective: LO 3.1: Explain the importance of the laws of thermodynamics to biological systems.

Section Reference: Section 3.1 Bioenergetics

37) What is the effect of a competitive inhibitor on an enzyme-mediated reaction? a) Vmax stays the same, KM decreases b) Vmax decreases, KM is decreased c) Vmax increases, KM is unchanged d) Vmax stays the same, KM is unchanged e) Vmax stays the same, KM increases Answer: e Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

38) Penicillin fits into the active site of transpeptidases and acts as what kind of inhibitor? a) irreversible and noncompetitive b) reversible only c) competitive and irreversible d) reversible and noncompetitive e) None of these are correct.

Answer: c Difficulty: Medium

Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

39) Which of these antibiotics does NOT target protein synthesis? a) macrolides b) lincosamides c) tetracyclines d) quinolones Answer: d Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

40) Strategies to combat antimicrobial drug resistance include all of the following EXCEPT: a) administering more than one antimicrobial drug concurrently b) designing drugs that avoid interacting with highly conserved areas of their target molecules c) isolating patients who are diagnosed with antibiotic resistant pathogens d) observing stricter hygienic practices when caring for those who are diagnosed with antibiotic resistant pathogens Answer: b Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

41) If an antibiotic were found to bind to a site on an essential bacterial enzyme other than the active site, what would its most likely mode of action be? a) competitive inhibitor b) noncompetitive inhibitor c) inhibitor of protein synthesis d) lowering activation energy

Answer: b Difficulty: Easy Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

42) An enzyme has a KM of 20 µM and a Vmax of 50 mmoles of product/minute/µg of enzyme.

After exposure to an inhibitor and analysis on a Lineweaver-Burk plot the following values are obtained: -1/ KM = - 0.05 liters/µmole and 1/ Vmax = 0.04 (mmoles of product/minute/µg of enzyme)-1. What kind of inhibitor was used in the experiment and what data interpretation supports this conclusion? a) noncompetitive inhibitor because the KM has remained the same and the Vmax has decreased b) competitive inhibitor because the KM has remained the same and the Vmax has decreased c) noncompetitive inhibitor because the KM has increased and the Vmax has decreased d) competitive inhibitor because the KM has increased and the Vmax has decreased Answer: a Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

43) An enzyme has a KM of 20 µM and a Vmax of 50 mmoles of product/minute/µg of enzyme.

After exposure to an inhibitor and analysis on a Lineweaver-Burk plot the following values are obtained: -1/ KM = - 0.03 liters/µmole and 1/ Vmax = 0.02 (mmoles of product/minute/µg of enzyme)-1. What kind of inhibitor was used in the experiment and what data interpretation supports this conclusion? a) noncompetitive inhibitor because the KM has remained the same and the Vmax has decreased b) competitive inhibitor because the KM has remained the same and the Vmax has decreased c) noncompetitive inhibitor because the KM has increased and the Vmax has decreased d) competitive inhibitor because the KM has increased and the Vmax remains the same Answer: d Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

44) Metabolic pathways that provide building blocks from which other molecules can be synthesized and that provide the chemical energy required for many cell activities are known as ______ reactions. a) anabolic b) catabolic c) allosteric d) anabolic and catabolic Answer: b Difficulty: Easy Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

45) A reaction involving the gain of one or more electrons is _________ reaction. a) an oxidation b) a reduction c) an inclusion d) an elimination Answer: b Difficulty: Easy Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

46) Glycolysis occurs in the ________; the Krebs (TCA) cycle occurs in the ______ of eukaryotes and the ______ of prokaryotes. a) cytoplasm, cytoplasm, cytoplasm b) mitochondria, cytoplasm, mitochondria c) cytoplasm, mitochondria, cytoplasm d) cytoplasm, photosynthesis, cytoplasm e) cytoplasm, mitochondria, mitochondria

Answer: c Difficulty: Medium Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

47) What kind of enzyme adds phosphate groups to enzymes for the purpose of activating or deactivating them? a) phosphatases b) protein kinases c) flippases d) glycosyltransferases e) carboxypeptidase Answer: b Difficulty: Easy Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

48) The hydrolysis of one glucose molecule has the potential to produce _______ ATP molecules in cells evolved to optimally catabolize it. a) 5 b) 10 c) 36 d) 120 Answer: c Difficulty: Easy Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

49) Although the glycolytic pathway is considered catabolic in purpose, some of the reactions within the pathway could be considered anabolic. Select the enzyme in glycolysis which catalyses an anabolic reaction. a) hexokinase b) phosphoglucose isomerase c) aldolase d) phosphoglycerate kinase Answer: a Difficulty: Hard Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

50) Although the glycolytic pathway is considered catabolic in purpose, some of the reactions within the pathway could be considered anabolic. Select the enzyme in glycolysis which catalyses an anabolic reaction. a) phosphofructokinase b) phosphoglucose isomerase c) aldolase d) phosphoglycerate kinase Answer: a Difficulty: Hard Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

51) Phosphorylation of glucose by hexokinase and phosphofructokinase is advantageous because: a) the sugar now has less activation energy b) a phosphorylated sugar is more likely to diffuse into the environment outside the cell c) glucose from outside the cell will continue to move into the cytoplasm of the cell d) all of these statements are correct Answer: c

Difficulty: Medium Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

52) The first exergonic reaction of glycolysis creates: a) Glucose 6-phosphate b) 3-phosphoglycerate c) pyruvate d) dihydroxyacetone phosphate Answer: a Difficulty: Medium Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

53) Given the ability of NADH to transfer energy from the high energy electrons it carries, it is a molecule most analogous to: a) glucose b) ADP c) ATP d) pyruvate Answer: c Difficulty: Medium Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

54) Possible fermentation products include all of the following EXCEPT: a) lactate produced in mammalian muscle cells b) ethanol produced in mammalian muscle cells c) ethanol produced in yeast cells d) ATP produced in yeast cells

Answer: c Difficulty: Easy Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

55) In glycolysis, fructose 1,6-biphosphate is split into two different molecules with distinct structures. Which enzyme is responsible for converting one of those molecules to be the same as the other? a) hexokinase b) phosphofructokinase c) triose phosphate isomerase d) enolase Answer: c Difficulty: Medium Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

56) You are studying metabolic pathways and discover that two pathways intersect so that the enzyme basinase participates in both of the intersecting pathways, in one case using substrate K and in the other using substrate M. When presented with substrate K in amounts significantly larger than M, basinase converts K to L which leads eventually to the production of the end product R. The activity of the second pathway is depressed simultaneously. In the presence of large amounts of substrate M and lower amounts of substrate K, the second pathway is activated and culminates in the production of that pathway's end product Y. The activity of the first pathway is depressed simultaneously. What are the alternative substrates K and M acting like? a) noncompetitive inhibitors b) competitive inhibitors c) irreversible inhibitors d) noncompetitive and irreversible inhibitors Answer: b Difficulty: Medium

Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2: Enzymes as Biological Catalysts

57) Below is a segment of a cell's collection of biochemical pathways. M is a product of one series of these reactions. It is also a regulatory molecule. Look at the pathway below and indicate the position(s) at which M is most likely to act as a feedback inhibitor when its concentration gets too high.

R 2

A

1

B

C

D 3

6

I J

4

K L 5

Q

P

10

9

O

N

8

M 7

a) Positions 1, 2, 8 b) Positions 4, 5, 7 c) Positions 1, 2, 3 d) Positions 8, 9, 10 Answer: c Difficulty: Medium Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

58) An enzyme which engages in an oxidation-reduction activity, transferring high energy electron and protons from a substrate onto a cofactor, is termed ____________________. a) a kinase b) a dehydrogenase c) an isomerase

d) a hydrolase Answer: b Difficulty: Easy Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

59) What is the activity of dehydrogenase enzymes destined to provide in a cell capable of respiration? a) increased ATP through NADH oxidation b) decreased ATP through NADH oxidation c) increased ATP through NADH reduction d) decreased ATP through NADH reduction Answer: a Difficulty: Medium Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

60) Which factors distinguish substrate-level phosphorylation from oxidative phosphorylation?

Select the INCORRECT response. a) substrate-level phosphorylation is catalyzed by an enzyme while oxidative phosphorylation requires an electron transport chain b) substrate-level phosphorylation uses ATP as the source of the phosphate group while oxidative phosphorylation uses Pi c) substrate-level phosphorylation uses a glycolytic intermediate as the source of the phosphate group while oxidative phosphorylation uses Pi d) substrate-level phosphorylation takes place in an aqueous environment while oxidative phosphorylation requires a hydrophobic environment.

Answer: c Difficulty: Hard Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

61) In cells relying exclusively upon glycolysis and substrate-level phosphorylation for ATP production, why is the production of reduced intermediates from pyruvate so essential? a) Reduction of pyruvate also allows for the reduction of NADH, providing NAD+ which is an essential substrate for the activity of glyceraldehyde phosphate dehydrogenase. b) Reduction of pyruvate allows for the oxidation of NADH, providing NAD+ which is an essential substrate for the activity of glyceraldehyde phosphate dehydrogenase. c) Reduction of pyruvate also allows for the reduction of NADH, providing NAD+ which is an essential substrate for the activity of triose phosphate isomerase. d) Reduction of pyruvate allows for the oxidation of NADH, providing NAD+ which is an essential substrate for the activity of triose phosphate isomerase.

Answer: b Difficulty: Hard Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

62) Plants can regulate proteins, chlorophylls and other factors required for photosynthesis via a light/dark independent regulatory mechanism known as a _______________________. a) regulating oscillator b) circadian oscillator c) diurnal oscillator d) entraining oscillator Answer: b Difficulty: Easy Learning Objective: LO 3.4: Explain how the light/dark cycle regulates plant metabolism Section Reference: Section 3.4: Green Cells: Regulation of Metabolism by the Light/Dark Cycle

63) Advantages derived from the use of a circadian oscillator regulatory mechanism include: a) less down regulation of proteins needed for photosynthesis during hours of total darkness b) reduced synthesis of essential photosynthesis proteins on cloudy days c) reduced synthesis of essential photosynthesis proteins at dawn and dusk

d) prediction of need for photosynthesis-related molecules to maximize photosynthesis during daylight hours Answer: d Difficulty: Medium Learning Objective: LO 3.4: Explain how the light/dark cycle regulates plant metabolism Section Reference: Section 3.4: Green Cells: Regulation of Metabolism by the Light/Dark Cycle

64) What is responsible for the periodicity that controls the production of essential photosynthetic enzymes and factors through the circadian oscillator? a) carbohydrate availability b) lipid levels within the cell c) a protein network synchronized through light sensitivity d) an RNA network synchronized through light sensitivity Answer: c Difficulty: Easy Learning Objective: LO 3.4: Explain how the light/dark cycle regulates plant metabolism Section Reference: Section 3.4: Green Cells: Regulation of Metabolism by the Light/Dark Cycle

65) Other than controlling the synthesis of photosynthesis-related proteins and other factors, which process has been observed in plants to be regulated by the circadian oscillator? a) flower production b) pollen release c) leaf curling d) root production Answer: c Difficulty: Easy Learning Objective: LO 3.4: Explain how the light/dark cycle regulates plant metabolism Section Reference: Section 3.4: Green Cells: Regulation of Metabolism by the Light/Dark Cycle

66) If you were comparing circadian oscillator structures between plant species, where might you predict that there would be the greatest differences?

a) between tropical orchids and arctic tundra wildflowers b) between east and west coast cereal crops grown at the same latitude c) between spring onion plants from the northern and southern hemisphere grown at the same distances away from the equator (each measured at their spring growth optimum) d) between plants in a garden grown in either a sunny or a shady spot Answer: a Difficulty: Hard Learning Objective: LO 3.4: Explain how the light/dark cycle regulates plant metabolism Section Reference: Section 3.4: Green Cells: Regulation of Metabolism by the Light/Dark Cycle

67) Tumor imaging can exploit soft tissue differences between normal and malignant cells by using all of the following EXCEPT: a) X-rays b) CAT scans c) infrared light d) positron emission Answer: c Difficulty: Easy Learning Objective: LO 3.5: Describe how their increased metabolic rate can be used to image tumors.

Section Reference: Section 3.5: Engineering Linkage: Using Metabolism to Image Tumors

68) 2-[18F] fluoro-2-deoxy-D-glucose (FDG) acts as a competitive inhibitor of ______________. a) all enzymes in glycolysis b) phosphoglucose isomerase c) hexokinase d) phosphofructokinase Answer: b Difficulty: Medium Learning Objective: LO 3.5: Describe how their increased metabolic rate can be used to image tumors.

Section Reference: Section 3.5: Engineering Linkage: Using Metabolism to Image Tumors

69) 2-[18F] fluoro-2-deoxy-D-glucose (FDG) accumulates within tumor cells engaging in higher than normal glycolytic activity. Which reactive functional group is missing in FDG, permitting its accumulation in tumor cells and their detection through PET scans? a) a methyl group b) a fluoride atom c) a phosphate group d) a hydroxyl group Answer: d Difficulty: Easy Learning Objective: LO 3.5: Describe how their increased metabolic rate can be used to image tumors.

Section Reference: Section 3.5: Engineering Linkage: Using Metabolism to Image Tumors

70) Fluorescein 18 emits ________________________ as it decays to another isotope. a) X-rays b) photons c) positrons d) electrons Answer: c Difficulty: Medium Learning Objective: LO 3.5: Describe how their increased metabolic rate can be used to image tumors.

Section Reference: Section 3.5: Engineering Linkage: Using Metabolism to Image Tumors

71) Fluorescein 18 emission from tumor cells is detected by a) an X-ray b) a photon c) a positron d) an electron Answer: b Difficulty: Medium

_________________ detector.

Learning Objective: LO 3.5: Describe how their increased metabolic rate can be used to image tumors.

Section Reference: Section 3.5: Engineering Linkage: Using Metabolism to Image Tumors

72) When using 2-[18F] fluoro-2-deoxy-D-glucose (FDG) uptake by tumor cells to detect cancerous masses, fluorescein 18 decays releasing __________. This in turn reacts with __________ and releases pairs of _________________ which are ultimately detected by the diagnostic scanner. a) an electron, a positron, photons b) a positron, an electron, photons c) a photon, an electron, positrons d) a photon, a positron, electrons Answer: b Difficulty: Medium Learning Objective: LO 3.5: Describe how their increased metabolic rate can be used to image tumors.

Section Reference: Section 3.5: Engineering Linkage: Using Metabolism to Image Tumors

73) Using an imaging technique such as positron emission tomography (PET) to detect cancer has all the advantages described EXCEPT: a) the image will be clearer than one derived from X-rays or CAT scans b) PET data can quantify the level of metabolic activity possessed by the tumor cells which may be useful in determining the rate of tumor growth c) PET data can predict the next area likely to be invaded by the tumor as it expands or the region to which stray tumor cells may move (metastasize). d) PET data can determine the size and shape of the tumor Answer: c Difficulty: Hard Learning Objective: LO 3.5: Describe how their increased metabolic rate can be used to image tumors.

Section Reference: Section 3.5: Engineering Linkage: Using Metabolism to Image Tumors

Question Type: Multiple Select

74) Why has the pharmaceutical industry drastically cut resources devoted to the development of new antibiotics? (Select all correct choices) a) The pharmaceutical industry views the period of time antibiotics need to be taken as too long, making it difficult to keep supply and demand in balance. b) The pharmaceutical industry views the period of time antibiotics need to be taken as too short, making it difficult to maintain profitability. c) Pharmaceutical companies view the inevitability of microbial resistance acquisition as a barrier to profitability since drugs that take a long time to produce will have a short market life. d) Pharmaceutical companies view the holding back of drugs of last resort, such as vancomycin, as sufficient to shore up the problem of drug resistance acquisition.

Answer: b, c, d Difficulty: Medium Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

Question Type: Multiple Select

75) You isolate the enzyme that synthesizes folic acid in bacteria and conduct some enzyme kinetics experiments. You find, not surprisingly, that sulfa drugs inhibit the enzyme's activity.

What happens to the Vmax and KM of this enzyme when it is treated with sulfa drugs? (Select all the correct statements relating to this experiment) a) sulfa drugs are competitive inhibitors of the folic acid synthesis pathway b) Vmax will stay the same and KM of this enzyme will decrease c) Vmax will decrease and KM of this enzyme will stay the same d) Vmax will increase and KM of this enzyme will increase e) Vmax will stay the same and KM of this enzyme will increase Answer: a, e Difficulty: Easy Learning Objective: LO 3.2: Explain how enzyme specificity may lower a reaction's activation energy.

Section Reference: Section 3.2 Enzymes as Biological Catalysts

Question Type: Multiple Select

76) If people are kept on diets containing about 25% fewer calories than would be required to maintain their initial body weight, what happens? (Select all correct responses) a) body temperature is raised b) insulin levels are lowered c) LDL cholesterol levels are lower d) DNA damage increases Answer: b, c Difficulty: Easy Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

Question Type: Multiple Select

77) If mice are maintained on very strict diets with reduced caloric intake, what happens to their life span as compared to littermates fed diets with normal caloric content and why? (Select all correct responses) a) mice live 30-40% longer b) mice experience a raise in body temperature c) mice synthesize higher concentrations of superoxide dismutase d) mice experience less free radical damage Answer: a, c, d Difficulty: Medium Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

Question Type: Multiple Select

78) Evidence suggests that lower levels of insulin in the blood may be important in promoting longevity. Which animal models have been used to gather this evidence? (Select all that apply) a) mice b) nematodes c) humans d) fruit flies Answer: c, d Difficulty: Medium Learning Objective: LO 3.3: Describe the differences between catabolic and anabolic pathways in biochemical reactions, including their intermediate steps.

Section Reference: Section 3.3: Metabolism

Question Type: Multiple Select

79) Which statements accurately describe the metabolism and detection of tumor cells? all that are correct choices)

(Select

a) tumor cells rely more on anaerobic activity than healthy cells b) tumor cells exhibit the Warburg effect c) injection of FDG into a cancer patient will allow fluorescent detection of the tumor region d) PET localization of tumor masses requires a single photon detector Answer: a, b, c Difficulty: Medium Learning Objective: LO 3.5: Describe how their increased metabolic rate can be used to image tumors.

Section Reference: Section 3.5: Engineering Linkage: Using Metabolism to Image Tumors

Question Type: Multiple Select

80) Which statements regarding the diagnosis and detection of brain tumors are INCORRECT? (Select all incorrect choices)

a) PET scanners will directly detect positrons emitted from fluorescein 18 incorporated into 2-deoxy- D-glucose b) PET scanners will indirectly detect positrons emitted from fluorescein 18 incorporated into 2-deoxy- D-glucose c) Tumor localization within the skull relies on tracking a pair of positrons back to the point where they diverged in position d) Tumor localization within the skull relies on tracking a pair of photons back to the point where they diverged in position Answer: a, c Difficulty: Medium Learning Objective: LO 3.5: Describe how their increased metabolic rate can be used to image tumors.

Section Reference: Section 3.5: Engineering Linkage: Using Metabolism to Image Tumors

Package Title: Test Bank Course Title: Karp9e Chapter Number: 4

Question Type: Multiple Choice

1) Which of the following is a function of membranes? a) compartmentalization b) creating a selectively permeable barrier c) mediating intercellular interactions d) helping cells respond to external stimuli e) all of these are correct choices Answer: e Difficulty: Easy Learning Objective: LO 4.1: Outline the general structure and functions of the plasma membrane. Section Reference: Section 4.1: Introduction to the Plasma Membrane

2) Which of the following is NOT a function of membranes? a) transporting solutes b) providing a scaffold for biochemical activities c) energy transduction d) signal transition e) signal transduction Answer: d Difficulty: Easy Learning Objective: LO 4.1: Outline the general structure and functions of the plasma membrane. Section Reference: Section 4.1: Introduction to the Plasma Membrane

3) What evidence convinced Overton that membranes were composed of lipids?

a) He could see the lipids in the microscope. b) Membranes were destroyed by enzymes that degraded lipids. c) More lipid-soluble solutes entered root hair cells faster than polar solutes. d) Membranes dissolved in gasoline. e) Membranes did not dissolve in water.

Answer: c Difficulty: Medium Learning Objective: LO 4.1: Outline the general structure and functions of the plasma membrane. Section Reference: Section 4.1: Introduction to the Plasma Membrane

4) Gorter and Grendel extracted lipids from human red blood cells. They calculated the total surface area for these red blood cell lipids and found it to be 36 µm2. How much surface area would these lipids cover once they were spread across the surface of water? a) 72 µm2 b) 36 µm2 c) 18 µm2 d) 144 µm2 e) 30 µm2 Answer: a Difficulty: Medium Learning Objective: LO 4.1: Outline the general structure and functions of the plasma membrane. Section Reference: Section 4.1: Introduction to the Plasma Membrane

5) What are the building blocks of a phosphoglyceride, specifically phosphatidic acid? a) glycerol + 2 phosphate groups + 1 fatty acid b) glycerol + 1 phosphate group + 2 fatty acids c) glycerol + 1 phosphate group d) glycerol + 3 fatty acids e) glycerol + 1 phosphate group + 3 fatty acids Answer: b Difficulty: Easy

Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

6) What word describes a molecule that contains both hydrophilic and hydrophobic portions? a) amphoteric b) ambidextrous c) amphipathic d) rings e) straight Answer: c Difficulty: Easy Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

7) Glycolipids have been shown to play roles in certain disease states in humans and other mammals. Which of the situations below illustrate the ways in which this can happen? a) malformed glycolipids can cause neurological disease b) mice with missing glycolipids had muscular tremors c) they are the site at which bacterial toxins like those that cause botulism and cholera first bind cells d) they are the site at which the influenza virus first binds a cell e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

8) Why did liposomes not work against diseases as hoped when they were first tried? a) They were not stable enough to last until their target destination.

b) Immune system phagocytes removed them from the bloodstream before they could exert an effect. c) They could not hold water soluble and lipid soluble drugs. d) They were targeted incorrectly. e) They expanded osmotically and lysed before reaching their target.

Answer: b Difficulty: Medium Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

9) How are the new "stealth liposomes" protected from immune system phagocytes? a) They are kept cold before use. b) They are coated with carbohydrates. c) They are given a synthetic polymer coating that protects them from immune destruction. d) They are loaded with radioactive isotopes. e) They are colored red.

Answer: c Difficulty: Easy Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

10) People who have the A blood type possess ________. a) an enzyme that adds an N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids b) an enzyme that adds a galactose to the end of the oligosaccharide chain on RBC membrane glycolipids c) an enzyme that adds phospholipids to the end of the oligosaccharide chain on RBC membrane glycolipids d) no enzymes capable of attaching galactose or N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids e) both an enzyme that adds an N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids and an enzyme that adds a galactose to the end of the oligosaccharide chain on RBC membrane glycolipids

Answer: a Difficulty: Medium Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

11) People who have the O blood type possess ________. a) an enzyme that adds an N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids b) an enzyme that adds a galactose to the end of the oligosaccharide chain on RBC membrane glycolipids c) an enzyme that adds phospholipids to the end of the oligosaccharide chain on RBC membrane glycolipids d) no enzymes capable of attaching galactose or N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids e) both an enzyme that adds an N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids and an enzyme that adds a galactose to the end of the oligosaccharide chain on RBC membrane glycolipids Answer: d Difficulty: Medium Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

12) Figure 4.12 shows the oligosaccharides attached to membrane lipids thus forming gangliosides that determine the A, B and O blood groups. Which statement regarding the arrangement of sugars is INCORRECT? a) A person with O blood type would have gangliosides with terminal fucose residues only exposed on their glycolipids. b) A person with A blood type would have gangliosides with both terminal fucose and terminal N-acetylgalactosamine residues exposed on their glycolipids. c) A person with B blood type would have gangliosides with terminal fucose and galactose residues on their glycolipids. d) A person with AB blood type would have gangliosides with terminal fucose, terminal N-acetylgalactosamine and terminal galactose residues exposed on their glycolipids. e) all statements are correct

Answer: e Difficulty: Medium Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

13) What kind of membrane protein penetrates into the hydrophobic part of the lipid bilayer? a) integral protein b) lipid-anchored protein c) peripheral protein d) phosphatidylcholine e) galactocerebroside Answer: a Difficulty: Medium Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

14) What kind of membrane protein is found entirely outside the bilayer on either the extracellular or cytoplasmic surface and is covalently linked to a membrane lipid situated within the bilayer? a) integral protein b) lipid-anchored protein c) peripheral proteins d) carbohydrate-anchored protein e) transmembrane Answer: b Difficulty: Medium Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

15) What kind of membrane protein penetrates into the hydrophobic part of the lipid bilayer?

a) integral protein b) lipid-anchored protein c) peripheral proteins d) transmembrane protein e) both integral protein and transmembrane protein Answer: e Difficulty: Medium Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

16) Which technique allows an investigation of the microheterogeneity of a membrane so that one can see localized differences in protein distribution within membranes? a) freeze-denture replication b) freeze-fracture replication c) X-ray crystallography d) circular dichroism e) quick-freeze replication Answer: b Difficulty: Easy Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

17) Why might integral membrane proteins be difficult to study based upon what you know of their amino acid composition? a) They are difficult to isolate in soluble form due to their hydrophobic transmembrane domains. b) They are difficult to isolate in soluble form due to their hydrophilic transmembrane domains. c) They are too small. d) They are too large. e) None of these are correct.

Answer: a Difficulty: Hard

Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

18) You treat some cells with a proteolytic enzyme that is too large to penetrate the cell membrane (Set 1). Another group of cells is made permeable to the enzyme before treatment with the enzyme (Set 2). A third set of cells was not treated with the enzyme at all (controls).

Proteins are then extracted from the three different sets of cells and applied to an SDS-PAGE gel. Protein W migrates to the same distance on a gel of proteins from Set 1 and Set 2; Protein W migrates a shorter distance on gels of proteins extracted from the control group than on gels of proteins extracted from Set 1 and Set 2 treated cells. Protein X migrates to the same distance on a gel of proteins from control cells and the gels of the proteins from Set 1 and Set 2. Protein Y migrates a longer distance when extracted from Set 1 cells than does protein Y in the controls; Protein Y moves an even larger distance in the gel of the extracts from Set 2. Protein Z migrates the same distance on gels of proteins from the controls and the proteins extracted from Set 1, but it migrates a longer distance in extracts from Set 2 cells. Which protein is exposed only on the exterior of the cell? a) Protein W b) Protein X c) Protein Y d) Protein Z Answer: a Difficulty: Hard Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

19) You treat some cells with a proteolytic enzyme that is too large to penetrate the cell membrane (Set 1). Another group of cells is made permeable to the enzyme before treatment with the enzyme (Set 2). A third set of cells was not treated with the enzyme at all (controls).

Proteins are then extracted from the three different sets of cells and applied to an SDS-PAGE gel. Protein W migrates to the same distance on a gel of proteins from Set 1 and Set 2; Protein W migrates a shorter distance on gels of proteins extracted from the control group than on gels of proteins extracted from Set 1 and Set 2 treated cells. Protein X migrates to the same distance on a gel of proteins from control cells and the gels of the proteins from Set 1 and Set 2. Protein Y migrates a longer distance when extracted from Set 1 cells than does protein Y in the controls; Protein Y moves an even larger distance in the gel of the extracts from Set 2. Protein Z migrates the same distance on gels of proteins from the controls and the proteins extracted from Set 1, but it migrates a longer distance in extracts from Set 2 cells.

Which protein is likely to have a cytosolic domain and be exposed only on the interior of the cell? a) Protein W b) Protein X c) Protein Y d) Protein Z Answer: d Difficulty: Hard Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

20) Once the structure of one member of a membrane protein family has been determined, researchers can usually apply a strategy called __________ to learn about the structure and activity of other members of the family. a) heterology modeling b) homology mapping c) homology modeling d) protein mapping e) homologous characterization Answer: c Difficulty: Medium Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

21) On average, how many amino acids, forming a hydrophobic a-helix, does it take to cross the hydrophobic part of the membrane? a) about 10 amino acids b) about 20 amino acids c) at least 40 amino acids d) about 2-3 amino acids e) None of these are correct.

Answer: b

Difficulty: Easy Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

22) What characterizes the amino acids that are found in an a-helical segment that spans a membrane? a) exclusively circular b) predominantly hydrophilic c) predominantly hydrophobic d) predominantly antiparallel e) totally parallel Answer: c Difficulty: Easy Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

23) What technique is often used to identify transmembrane segments of integral proteins? a) Lineweaver-Burk plot b) Michaelis-Menten plot c) hydrophilicity plot d) hydropathy plot e) titration plot Answer: d Difficulty: Easy Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

24) A procedure in which the gene for an integral membrane protein is altered in such a way that the spatial relationships between some of the amino acids in the protein can be revealed is called ________.

a) site-directed mutagenesis b) site-directed hydropathy c) hydropathy plots d) electron paramagnetic resonance (EPR) spectroscopy e) infrared spectroscopy Answer: a Difficulty: Easy Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

25) Using the nucleotide sequence of a gene, which of the following can be learned from a computer-based (computational) analysis of the primary amino acid structure of a membrane protein? a) its structure b) its orientation within the lipid bilayer c) its concentration in each cell d) both its structure and its orientation within the lipid bilayer Answer: d Difficulty: Medium Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

26) An amino acid is made to replace another amino acid in membrane-spanning a-helices by site-directed mutagenesis of the gene coding for the protein. This is done in order to determine how close together two such a-helices are in the structure of an integral protein. The amino acid is added to facilitate the attachment of a nitroxide group which can be used to detect position The amino acid substituted is:____________________. a) phenylalanine b) alanine c) cysteine d) methionine e) proline

Answer: c Difficulty: Medium Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

27) What technique utilizes the properties of nitroxides to be sensitive to the distance that separates them and an unpaired electron? a) site-directed mutagenesis b) site-directed amenuensis c) hydropathy plots d) electron paramagnetic resonance (EPR) spectroscopy e) infrared spectroscopy Answer: d Difficulty: Easy Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

28) Which of the following is NOT an observed function of peripheral proteins? a) mechanical support for membrane b) enzyme activity c) receptor activity d) anchor for integral proteins e) factors that transmit transmembrane signals Answer: c Difficulty: Medium Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

29) Which enzyme releases certain membrane proteins from a membrane and was instrumental in the discovery of GPI-anchored proteins?

a) phospholipase b) lipase c) hydroxyurease d) protease e) trypsin Answer: a Difficulty: Medium Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

30) The temperature at which a lipid bilayer shifts from a fluid state to a crystalline gel is called the _____________. a) transition temperature b) temperature optimum c) transition series d) pH optimum e) gelation temperature Answer: a Difficulty: Easy Learning Objective: LO 4.4: Explain the importance of fluidity to plasma membrane properties.

Section Reference: Section 4.4: Membrane Lipids and Membrane Fluidity

31) Which property of membranes allows interactions like the assembly of membrane protein clusters at particular sites and the formation of specialized structures to take place within the membrane? a) hydrophobicity b) hydrophilicity c) membrane fluidity d) their amphipathic nature e) their amphoteric nature Answer: c Difficulty: Medium

Learning Objective: LO 4.4: Explain the importance of fluidity to plasma membrane properties.

Section Reference: Section 4.4: Membrane Lipids and Membrane Fluidity

32) While culturing some cells, you lower the temperature of the culture. What happens immediately to the membrane fluidity? a) Nothing happens. b) The membrane becomes less fluid. c) The membrane becomes more fluid. d) The membrane fluidity fluctuates back and forth from high to low. e) The membrane fluidity fluctuates back and forth from low to high.

Answer: b Difficulty: Hard Learning Objective: LO 4.4: Explain the importance of fluidity to plasma membrane properties.

Section Reference: Section 4.4: Membrane Lipids and Membrane Fluidity

33) Which of the following cell processes depend on the movement of membrane components and would probably not be possible if membranes were rigid, nonfluid structures? a) cell movement b) cell division c) formation of intercellular junctions d) endocytosis e) all of these are correct Answer: e Difficulty: Easy Learning Objective: LO 4.4: Explain the importance of fluidity to plasma membrane properties.

Section Reference: Section 4.4: Membrane Lipids and Membrane Fluidity

34) Enzymes which play a role in maintaining cellular integrity by stabilizing membrane fluidity include all of the following EXCEPT: a) dehydrogenases b) desaturases c) phospholipases d) acyltransferases

e) phospholipid synthesizing enzymes Answer: a Difficulty: Medium Learning Objective: LO 4.4: Explain the importance of fluidity to plasma membrane properties.

Section Reference: Section 4.4: Membrane Lipids and Membrane Fluidity

35) In colder weather, a bird’s cells would need to __________________ in order to best modify the fatty acid composition of lipid membranes and maintain membrane fluidity homeostasis. a) increase incorporation of saturated fatty acids b) increase incorporation of unsaturated fatty acids c) decrease incorporation of saturated fatty acids d) decrease incorporation of unsaturated fatty acids e) both an increase in incorporation of unsaturated fatty acids and a decreased incorporation of saturated fatty acids would be optimum f) both a decrease in incorporation of unsaturated fatty acids and an increased incorporation of saturated fatty acids would be optimum Answer: e Difficulty: Medium Learning Objective: LO 4.4: Explain the importance of fluidity to plasma membrane properties.

Section Reference: Section 4.4: Membrane Lipids and Membrane Fluidity

36) Which of the following genetic diseases is characterized by fragile, abnormally shaped erythrocytes and has been traced to mutations in ankyrin or spectrin? a) hemophilia b) sickle cell anemia c) hemolytic anemias d) leukemia e) erythroblastosis Answer: c Difficulty: Medium Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

37) Hemolytic anemias are characterized by fragile, abnormally shaped erythrocytes; the disease has been traced to mutations in ________. a) both actin and spectrin b) both actin and ankyrin c) hemoglobin d) spectrin e) both ankyrin and spectrin Answer: e Difficulty: Medium Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

38) How was the asymmetry of membrane lipids discovered? a) visualization in the electron microscope b) observation with a special stain in the light microscope c) treatment of intact red blood cells with phospholipases d) treatment of intact red blood cells with trypsin e) treatment of liver cells with phospholipases Answer: c Difficulty: Medium Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

39) Which of the following is NOT a potential biological role of the lipid asymmetry of the plasma membrane? a) The glycolipids in the outer leaflet of the membrane may serve as receptors. b) The presence of phosphatidylinositol primarily in the inner leaflet is involved in signal transduction. c) The cell has the ability to maintain a charge differential in the two membrane leaflets. d) Appearance of phosphatidylserine on the outer surface of aging lymphocytes marks them for destruction by macrophages.

e) Phosphatidylserine on the surface of platelets serves as a signal for blood solubilization.

Answer: e Difficulty: Easy Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

40) Phosphatidylethanolamine is concentrated in the inner leaflet of the plasma membrane and tends to promote the curvature of the membrane, which is important in _________. a) membrane budding b) membrane fragmentation c) membrane fusion d) signal transduction and membrane fusion e) both membrane budding and membrane fusion Answer: e Difficulty: Medium Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

41) When membrane lipids are extracted from cells and used to prepare artificial lipid bilayers, cholesterol and sphingolipids tend to self-assemble into ________ that are more gelated and highly ordered than surrounding regions consisting primarily of _________. a) macrodomains, phosphoglycerides b) microdomains, integral proteins c) microdomains, phosphoglycerides d) liquid crystals, phosphoglycerides e) liquid crystals, microdomains Answer: c Difficulty: Medium Learning Objective: LO 4.4: Explain the importance of fluidity to plasma membrane properties.

Section Reference: Section 4.4: Membrane Lipids and Membrane Fluidity

42) Concentrated areas of sphingolipids and cholesterol that are more gelated and ordered than the surrounding fluid membrane are called ______________ . a) lipid islands b) collections c) lipid rafts d) lipid domains e) dense bilayers Answer: c Difficulty: Medium Learning Objective: LO 4.4: Explain the importance of fluidity to plasma membrane properties.

Section Reference: Section 4.4: Membrane Lipids and Membrane Fluidity

43) Enzymes that move certain phospholipids between leaflets also have which of the following properties? a) able to establish and maintain membrane lipid asymmetry b) interact with neighboring epithelial cells, or the basal membrane c) block post-synaptic membrane signals d) transport proteins across the membrane e) all of the above Answer: a Difficulty: Easy Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

44) You fuse a mouse cell and a human cell and then treat the cell with anti-mouse or anti-human protein-directed antibodies that are covalently linked to fluorescent dyes (antibodies to mouse proteins show green fluorescence; antibodies to human proteins show red fluorescence). What does the cell look like immediately after fusion? a) The cell is half red and half green. b) The red and green labels are uniformly distributed across the entire membrane. c) The red and green labels are distributed in intermingled patches. d) The cell appears to be yellow in color. e) The cell appears to be brown in color.

Answer: a Difficulty: Hard Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

45) You fuse a mouse cell and a human cell and then treat the cell with anti-mouse or anti-human protein-directed antibodies that are covalently linked to fluorescent dyes (antibodies to mouse proteins show green fluorescence; antibodies to human proteins show red fluorescence). What does the cell look like after one hour? a) The cell is half red and half green. b) The red and green labels are uniformly distributed across the entire membrane. c) The red and green labels are distributed in intermingled patches. d) The cell appears to be yellow in color. e) The cell appears to be brown in color.

Answer: b Difficulty: Hard Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

46) _________ is a technique that can be used to trap integral proteins and drag them through the membrane with a known force, using forces generated by a focused laser beam. a) FRAP b) SPT c) Fluorescence recovery after photobleaching d) Optical tweezer manipulation e) SDS-PAGE Answer: d Difficulty: Easy Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

47) Usually, optical tweezers drag integral proteins a limited distance before they encounter a barrier that causes their release; upon release, they typically spring backward. What does this suggest? a) the presence of solid barriers b) the presence of elastic barriers c) the attachment of the proteins to the cytoskeleton d) the attachment of the proteins to the endoplasmic reticulum e) the presence of rubber in the membrane Answer: b Difficulty: Medium Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

48) You modify the gene for an integral membrane protein so that the cytoplasmic portions of the protein are deleted. When the gene is inserted in cells, what happens to the mobility of this protein in the membrane? a) It moves much greater distances than the intact protein. b) It moves much smaller distances than the intact protein. c) It does not move at all. d) It is not inserted into the membrane so nothing can be learned about their mobility. e) It flips to the opposite leaflet.

Answer: a Difficulty: Medium Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

49) Integral membrane proteins have been engineered to lack the portion that normally projects into the extracellular space. When the gene is inserted in cells, what happens to the mobility of this protein in the membrane? a) It moves at a much faster rate than the wild type protein. b) It moves at a much slower rate than the intact protein. c) It does not move at all. d) It is not inserted into the membrane so nothing can be learned about their mobility.

e) It flips to the opposite leaflet.

Answer: a Difficulty: Medium Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

50) What happens to phospholipid mobility when the cell is treated with agents that disrupt the underlying membrane skeleton? a) Mobility is unchanged. b) Mobility is increased because the fences that normally restrict their diffusion are removed. c) Mobility is decreased because the fences that normally restrict their diffusion are removed. d) Mobility is increased because the treatment raises the temperature. e) Mobility is decreased because the treatment lowers the temperature.

Answer: b Difficulty: Medium Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

51) Why are proteins separated on an SDS polyacrylamide gel equally attracted to the positive electrode? a) They carry a relatively uniform positive charge distribution b) They carry a relatively uniform negative charge distribution. c) They are all the same molecular weight. d) They are all the same size. e) They all have the same degree of hydrophobicity.

Answer: b Difficulty: Medium Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

52) Which proteins move the farthest during SDS-polyacrylamide gel electrophoresis? a) the largest b) the smallest c) the most negative d) the most positive e) both the largest and the most negative Answer: b Difficulty: Medium Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

53) Which protein in the red blood cell membrane appears to be responsible for the exchange of bicarbonate ions and chloride ions across the red blood cell membrane? a) glycophorin A b) glycophorin D c) band 3 d) glyceraldehyde 3-phosphate e) alpha-actinin Answer: c Difficulty: Easy Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

54) Which protein(s) below is(are) thought to be involved in and influence the stability of red blood cell membranes and the cells themselves by imparting strength, elasticity, and pliability to the membrane? a) actin and tropomyosin b) spectrin c) band 3 d) ankyrin e) all of these are correct

Answer: e Difficulty: Medium Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

55) _________ is the movement of a substance from an area of high concentration to an area of lower concentration. a) Denaturation b) Osmosis c) Diffusion d) Transport e) Defusion Answer: c Difficulty: Easy Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

56) Why would a transverse diffusion or flip-flop of membrane phospholipids from one leaflet to the other be so rare? a) Flippases are enzymes which are transiently stable and expressed at low concentrations. b) For flip-flop to occur, it would be necessary for the hydrophilic head of a phospholipid to move through the hydrophobic part of the bilayer, an extremely unlikely event. c) For flip-flop to occur, it would be necessary for the hydrophobic head of a phospholipid to move through the hydrophilic part of the bilayer, an extremely unlikely event. d) Other membrane activities like flexing and lateral shift inhibit phospholipid flip-flop.

Answer: b Difficulty: Medium Learning Objective: LO 4.5: Identify techniques for studying the movement of molecules within the plasma membrane.

Section Reference: Section 4.5: The Dynamic Nature of the Plasma Membrane

57) The movement of water through a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration is called ________. a) diffusion b) osmosis c) denaturation d) metabolism e) solubility Answer: b Difficulty: Medium Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

58) A channel that opens in response to changes in ionic charge across a membrane is called a ________. a) voltage-gated channel b) charge-gated channel c) ligand-gated channel d) positive-gated channel e) electric-gated channel Answer: a Difficulty: Easy Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

59) Which substance will cross a plasma membrane most effectively? a) Molecule AA with an octanol-water partition coefficient of 5 b) Molecule AB with an octanol-water partition coefficient of 0.5 c) Molecule AC with an octanol-water partition coefficient of 50 d) Molecule AD with an octanol-water partition coefficient of 0.05 Answer: c Difficulty: Medium Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

60) What is thought to be important in maintaining the native structure of the Kv channel membrane protein and promoting its function as a voltage-gated channel? a) negatively charged cholesterol b) positively charged sphingolipids c) negatively charged phospholipids d) positively charged phospholipids e) negatively charged sphingolipids Answer: c Difficulty: Medium Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

61) A channel that opens in response to the binding of a specific molecule, which is usually not the solute that passes through the channel is called a ________. a) voltage-gated channel b) charge-gated channel c) ligand-gated channel d) positive-gated channel e) electric-gated channel Answer: c Difficulty: Easy Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

62) Diffusion during which the substance to be transported binds selectively to a membrane-spanning protein, which helps the process along, is called ________. a) osmosis b) facilitated osmosis c) simple diffusion d) facilitated diffusion e) active transport

Answer: d Difficulty: Easy Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

63) An important aspect of transport by facilitated transporters and pumps is ________. a) conformational shifts b) rigidity c) softness d) a-helix secondary structure e) b-pleated sheet secondary structure Answer: a Difficulty: Medium Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

64) The sodium-potassium pump makes the cell interior more _________ by pumping _______ sodium ions out of the cell for every ___________ potassium ions pumped in. a) negative, 3, 2 b) negative, 2, 3 c) positive, 3, 2 d) positive, 2, 3 e) negative, 4, 3 Answer: a Difficulty: Hard Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

65) What is the distinguishing characteristic of a P-type pump? a) It must be pumped during the cycle. b) It must be phosphorylated during the cycle. c) It must be protonated during the cycle. d) It must be methylated during the cycle.

e) It must be acetylated during the cycle.

Answer: b Difficulty: Medium Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

66) In the Na+/glucose cotransporter, _________ moving down its gradient drives the transport of __________ against its gradient. a) Na+ ions, K+ ions b) Na+ ions, glucose c) glucose, Na+ ions d) glucose, K+ ions e) K+ ions, glucose Answer: b Difficulty: Easy Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

67) A transport system that moves one solute into the cell and another one out of the cell during a single cycle accompanied by the expenditure of energy through ATP hydrolysis could be called _______ a) an active antiport b) an active uniport c) a passive antiport d) an active symport e) a passive symport Answer: a Difficulty: Medium Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

68) The ability, possessed by all organisms, to respond to external stimulation is known as _______. a) excitation b) irritability c) irritation d) irrigation e)receptiveness Answer: b Difficulty: Easy Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

69) Where is the neuron cell nucleus located? a) axon hillock b) cell body c) dendrites d) axon e) terminal knob Answer: b Difficulty: Easy Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

70) Which site in a neuron receives incoming information from external sources? a) Dendrites b) Axon c) Axon hillock d) Terminal knob e) Cell body Answer: a Difficulty: Easy

Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

71) Which part of a neuron conducts impulses away from the cell body toward the target cell(s)? a) axon hillock b) cell body c) dendrites d) axon e) terminal knob Answer: d Difficulty: Easy Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

72) As an action potential is initiated, the membrane is __________. This is caused by the ________ of ________ ions. a) hyperpolarized, efflux, Na+ b) depolarized, influx, Na+ c) depolarized, influx, K+ d) hyperpolarized, influx, Na+ e) depolarized, efflux, Na+ Answer: b Difficulty: Hard Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

73) How do Na+ ions enter a neuron when an action potential is initiated? a) the Na+/K+-ATPase b) a gated Na+ pump c) a voltage-gated Na+ channel d) the ligand-gated Na+ channel

e) a voltage-gated Na+ facilitated transporter Answer: c Difficulty: Medium Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

74) What causes the membrane potential to return to the normal negative value after an action potential has occurred? a) opening of a voltage-gated K+ channel b) opening of a voltage-gated Na+ channel c) closing of a voltage-gated K+ channel d) opening of a ligand-gated Na+ channel e) opening of a voltage-gated K+ facilitated transporter Answer: a Difficulty: Medium Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

75) What is caused by the inability of Na+ ion channels to open for several milliseconds after their inactivation? a) hyperpolarization b) depolarization c) termination d) a refractory period e) an action potential Answer: d Difficulty: Easy Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

76) What is thought to cause the 1 ms inactive time after a sodium channel initiates an action potential? a) a higher positive charge b) a higher negative charge c) the presence of an inactivating peptide in the opening of the channel pore d) removal of a peptide from the channel protein e) covalent addition of a peptide to the cytoplasmic end of the channel protein Answer: c Difficulty: Medium Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

77) What happens after a subthreshold depolarization? a) a full action potential b) a partial action potential c) no action potential d) a proportional action potential e) a reversal of the direction of the neural impulse Answer: c Difficulty: Medium Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

78) Where in a myelinated axon are nearly all of the ion channels concentrated? a) the cell body b) nodes of Ranvier c) dendrites d) axon terminals e) neuron nucleus Answer: b

Difficulty: Easy Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

79) Impulse propagation by a myelinated axon is called ____________ conduction. a) saltatory b) myelinated c) rapid fire d) jump stop e) leap frog Answer: a Difficulty: Easy Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

80) Which disease is caused by the deterioration of the myelin sheath? a) myasthenia gravis b) multiple sclerosis c) muscular dystrophy d) diabetes mellitus e) lupus erythematosus Answer: b Difficulty: Easy Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

81) How is a nerve impulse usually transmitted across a synapse from a presynaptic to a postsynaptic cell? a) via a direct connection b) via a spark

c) via a neurotransmitter d) via Na+ ions e) via plasmodesmata Answer: c Difficulty: Medium Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

82) ______influx triggers fusion of synaptic vesicles with the synaptic membranes of the presynaptic cell. This same stimulus also triggers __________, releasing neurotransmitters. a) Ca2+ ion, exocytosis b) Ca2+ ion, endocytosis c) acetylcholine molecules, exocytosis d) acetylcholine molecules, endocytosis e) Na+ ion, exocytosis Answer: a Difficulty: Medium Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

83) Cocaine acts by _________. a) enhancing the degradation of acetylcholine b) depressing the degradation of acetylcholine c) interfering with dopamine reuptake from the synaptic cleft d) enhancing dopamine reuptake from the synaptic cleft e) destroying dopamine in the synapse Answer: c Difficulty: Medium Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

84) Tetrahydrocannabinol, the active ingredient in marijuana, binds to receptors located in the ____________ terminals of certain brain neurons. It lowers the likelihood that these neurons will release ___________. a) postsynaptic, neurotransmitters b) presynaptic, neurotransmitters c) presynaptic, Ca2+ ions d) postsynaptic, Ca2+ ions e) dendritic, neurotransmitters Answer: b Difficulty: Medium Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

85) ___________ is a process that strengthens certain synapses by repeated neuron stimulation over a short time period. a) Denaturation b) Long term potentiation c) Short term memory d) Temporality e) Long term deviation Answer: b Difficulty: Easy Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

86) Long-term potentiation is associated with NMDA receptors, one of several types of receptors that bind to the excitatory neurotransmitter __________. Its binding opens an internal cation channel within the receptor that allows __________ influx into the postsynaptic neuron, triggering a cascade of biochemical changes that lead to synaptic strengthening. a) GABA, Ca2+ ion b) glutamate, Ca2+ ion

c) glutamate, K+ ion d) GABA, K+ ion e) acetylcholine, Ca2+ ion Answer: b Difficulty: Medium Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

87) Synaptic malfunction or dysfunction may cause which of the following diseases? a) myasthenia gravis b) Parkinson's disease c) schizophrenia d) depression e) all of these are correct Answer: e Difficulty: Easy Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

Question type: Multiple Select

88) In a comparison of action potentials occurring in plant versus animal cells, which of the following statements is/are correct? (Select all correct choices) a) Plant cells have a higher chloride ion concentration outside the cell than inside, similar to animal neuronal cells. b) Plant cells have a higher chloride ion concentration outside the cell than inside, which is the opposite of the animal neuron cell concentrations. c) Plant action potentials are triggered by mechanosensory ion channels while animal action potentials are triggered by voltage dependent ion channels. d) In plant cells, chloride ion flux results in an action potential, while sodium ion flux initiates an animal neuron action potential.

Answer: b, c, d Difficulty: Hard Learning Objective: LO 4.8: Describe how electrical signaling occurs in plants.

Section Reference: Section 4.8: Green Cells: Electrical Signaling in Plants

Question type: Multiple Choice

89) In plants, the analogous mechanism to action potential propagation in animal neuron axons is _________________________. a) plant cells also possess neurons with elongated axons b) movement of an action potential through xylem c) movement of an action potential through phloem d) saltatory conduction from one leaf to another Answer: c Difficulty: Easy Learning Objective: LO 4.8: Describe how electrical signaling occurs in plants.

Section Reference: Section 4.8: Green Cells: Electrical Signaling in Plants

90) Venus fly trap responses to action potentials are characterized by: a) immediate closure of the trap after a single stimulus b) closure of the trap after 30 stimuli c) weak closure when a larger number of stimuli are received received) firm closure of the trap when a large number of stimuli are received Answer: d Difficulty: Medium Learning Objective: LO 4.8: Describe how electrical signaling occurs in plants.

Section Reference: Section 4.8: Green Cells: Electrical Signaling in Plants

91) Arabidopsis membrane depolarization is characterized by all of the following statements EXCEPT: a) plasma membrane depolarization spreads by passive electrical conduction

b) depolarization lasts much longer than a typical animal neuron action potential c) Arabidopsis mutants can be used to identify receptors and ion channels involved in the depolarization events d) depolarization leads to the response of increased photosynthesis by Arabidopsis Answer: d Difficulty: Medium Learning Objective: LO 4.8: Describe how electrical signaling occurs in plants.

Section Reference: Section 4.8: Green Cells: Electrical Signaling in Plants

92) To date, the most successful neurotechnology advances have occurred in _________________. a) restoration of sight b) restoration of hearing c) restoration of mobility d) restoration of balance Answer: b Difficulty: Easy Learning Objective: LO 4.9: Identify the clinical applications of neurotechnology.

Section Reference: Section 4.9: Engineering Linkage: Neurotechnology

93) What features of the cochlea make providing implants to improve hearing less challenging that attempting to restore mobility? a) The spiral shape of the cochlea is designed to detect different sound frequencies at different positions along its length, which assists in sending the correct signals to auditory neurons. b) The length of the cochlea allows multiple electrodes to be spaced efficiently. c) The length of the cochlea reduces the need for extremely high density electrode arrays. d) All are correct choices.

Answer: d Difficulty: Medium Learning Objective: LO 4.9: Identify the clinical applications of neurotechnology.

Section Reference: Section 4.9: Engineering Linkage: Neurotechnology

Question Type: Multiple Select

94) People who have the AB blood type possess _____________. (Select all correct choices) a) an enzyme that adds an N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids b) an enzyme that adds a galactose to the end of the oligosaccharide chain on RBC membrane glycolipids c) an enzyme that adds phospholipids to the end of the oligosaccharide chain on RBC membrane glycolipids d) no enzymes capable of attaching galactose or N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids Answer: a, b Difficulty: Medium Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

Question type: Multiple Select

95) Referring to Figure 4.9 (Insert Figure 4.9 if necessary) which statements regarding the stealth liposome are correct? (Select all that apply) a) The polyethylene glycol will protect the stealth liposome from destruction by immune cells. b) Antibodies in the stealth liposome membrane will target it to the specific body tissues for which it is intended. c) Lipid-soluble drugs are found in the stealth liposome's lipid bilayer and the water-soluble drugs are found in the fluid-filled interior chamber of the stealth liposome. d) Lipid-soluble drugs are found in the lipid-filled interior chamber of the stealth liposome and the water-soluble drugs are found in stealth liposome's lipid bilayer.

Answer: a, b, c Difficulty: Medium Learning Objective: LO 4.2: Identify the basic structures and functions of the carbohydrates and lipids within cellular membranes.

Section Reference: Section 4.2: The Chemical Composition of Membranes

Question type: Multiple Select

96) GPI-anchored proteins play an essential role in maintaining the health and integrity of the nervous and cardiovascular systems. When synthesis is altered or defective, diseases such as ______________ can be observed in humans. (Select all that are correct choices) a) sickle cell anemia b) paroxysmal nocturnal hemoglobinuria c) Creutzfeld-Jakob syndrome variant d) aplastic anemia Answer: b, c Difficulty: Easy Learning Objective: LO 4.3: Describe the three classes of membrane proteins and their functions within the lipid bilayer.

Section Reference: Section 4.3: Membrane Proteins

Question type: Multiple Select

97) What factor(s) directly or indirectly determine the transition temperature? correct choices)

(Select all

a) the ability of lipid molecules to be packed together b) whether the fatty acid chains of the lipids are saturated or unsaturated c) the extent to which the fatty acid chains of the lipids contain double bonds d) the length of the fatty acid chains Answer: a, b, c, d Difficulty: Medium Learning Objective: LO 4.4: Explain the importance of fluidity to plasma membrane properties.

Section Reference: Section 4.4: Membrane Lipids and Membrane Fluidity

Question type: Multiple Select

98) In what way can a given solute get through a membrane? (Select all correct choices) a) The solute can pass through the bilayer. b) The solute can pass through cholesterol. c) The solute can pass through an aqueous channel. d) The solute can pass through a pore.

Answer: a, c, d Difficulty: Easy Learning Objective: LO 4.6: Explain how substances move across the cell membrane.

Section Reference: Section 4.6: The Movement of Substances Across Cell Membranes

Question type: Multiple Select

99) What causes the refractory period in sodium channels after an action potential has been initiated? (Select all correct responses) a) The sodium channels must close before they can be reopened in response to another stimulus. b) The ion channel can only transform from the inactivated to the closed conformation after the inactivating peptide has swung out of the pore opening. c) The ion channel can only transform from the closed to the inactivated conformation after the inactivating peptide has swung out of the pore opening. d) The inactivating peptide must bind to the pore opening more tightly before the channel can be restimulated.

Answer: a, b Difficulty: Hard Learning Objective: LO 4.7: Explain the resting potential, action potential, and propagation of nerve impulses.

Section Reference: Section 4.7: Membrane Potentials and Nerve Impulses

Question type: Multiple Select

100) Neurotechnology bioengineering goals include:

(Select all correct choices)

a) stimulation of the visual pathway by providing signals to the retina b) stimulation of the visual pathway by providing signals to the optic nerve c) better coordination signals within prosthetic limb devices d) behavior modification signals to control psychotic impulses in criminals Answer: a, b, c Difficulty: Medium Learning Objective: LO 4.9: Identify the clinical applications of neurotechnology.

Section Reference: Section 4.9: Engineering Linkage: Neurotechnology

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 5

Question Type: Multiple Choice

1) Which of the following is not found in a reducing atmosphere? a) H2 b) NH3 c) O2 d) H2O e) Both O2 and H2O Answer: c Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

2) What advantage do the cristae confer on the mitochondria? a) They allow the mitochondria to shrink. b) They greatly increase the surface area for aerobic respiration machinery. c) They confer resiliency on the cells. d) They allow swelling of mitochondria. e) They activate the matrix.

Answer: b Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

3) The presence of Ca2+ ion transport molecules in the inner mitochondrial membrane is consistent with the mitochondrion's role in _______.

a) muscle contraction b) regulating cytosolic Ca2+ ion concentration c) ATP production d) ADP production e) control of membrane fusion Answer: b Difficulty: Easy Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

4) Mitochondria are sites of the __________. a) synthesis of certain amino acids b) synthesis of heme groups c) uptake of Ca2+ ions d) release of Ca2+ ions e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

5) Which of the following is regulated by mitochondria? a) cytosolic levels of chloride ions b) intracellular levels of K+ ions c) cytosolic levels of Ca2+ ions d) process of closure in endocytosis Answer: c Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

6) What are the two interconnected domains of the inner mitochondrial membrane? a) inner boundary membrane, cristae b) central boundary membrane, cristae c) cristae boundary membrane, outer boundary membrane d) inner boundary membrane, outer boundary membrane e) cristae, matrix Answer: a Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

7) What is defined as a domain of the inner mitochondrial membrane that is present within the interior of the mitochondrion as a series of invaginated membranous sheets? a) inner boundary membrane b) outer boundary membrane c) cristae d) matrix e) pseudopodia Answer: c Difficulty: Easy Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

8) The inner boundary membrane is particularly rich in which of the following? a) protons b) transporter proteins responsible for the import of mitochondrial proteins c) Krebs cycle enzymes d) enzymes of the glycolytic pathway e) glycosaminoglycans

Answer: b Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

9) What evidence suggests that the outer mitochondrial membrane has evolved from the outer membrane that is part of the cell wall of certain bacteria? a) the presence of porins in both membranes b) the virtual absence of cholesterol from both membranes c) both membranes being rich in cardiolipin d both membranes being rich in diphosphatidylglycerol Answer: a Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

10) From what does the mitochondrial RNA polymerase appear to have evolved? a) the multisubunit RNA polymerase found in prokaryotic cells b) the multisubunit RNA polymerase found in eukaryotic cells c) the multisubunit RNA polymerase found in bacterial viruses (bacteriophage) d) the single subunit RNA polymerase found in bacterial viruses (bacteriophage) Answer: d Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

11) In which two alternative ways can pyruvate and NADH be metabolized? a) fermentation; hydrolysis of PGAL b) condensation of PGAL; fermentation c) aerobic processes using the Krebs cycle; fermentation d) anaerobic processes using the Krebs cycle; fermentation

e) aerobic processes using the Krebs cycle; hydrolysis of PGAL Answer: c Difficulty: Hard Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

12) How many carbons from one original glucose molecule enters the Krebs cycle in a cell capable of respiration? a) 0 b) 1 c) 2 d) 4 e) 5 Answer: d Difficulty: Hard Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

13) How many carbons from one original glucose molecule enters the Krebs cycle in a cell in which respiration does not take place? a) 0 b) 1 c) 2 d) 4 e) 5 Answer: a Difficulty: Medium Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

14) What happens to the carbons of pyruvate that do not enter the Krebs cycle?

a) They are converted to carbohydrates. b) They are converted to CO2. c) They are converted to glucose. d) They are converted to ATP. e) They are converted to carbon monoxide (CO).

Answer: b Difficulty: Medium Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

15) What molecule is responsible for conveying 2 carbons from pyruvate to the Krebs cycle? a) Coenzyme G b) Coenzyme A c) Acetate d) pyruvate e) oxaloacetate Answer: b Difficulty: Easy Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

16) Which component involved in the Krebs (TCA) cycle is bound to the inner mitochondrial membrane? a) oxaloacetate b) acetyl CoA c) succinate dehydrogenase d) succinate e) succinyl CoA Answer: c Difficulty: Easy Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

17) Where are most of the enzymes of the Krebs cycle located? a) in the intercristal space b) on the cristae c) on the ribosomes d) in the soluble phase of the mitochondrial matrix e) in the intermembrane space Answer: d Difficulty: Easy Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

18) To what is the 2-carbon fragment of acetyl CoA added to make citric acid at the start of the Krebs cycle? a) oxaloacetate b) citric acid c) succinate d) α-ketoglutarate e) isocitric acid Answer: a Difficulty: Easy Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

19) What is the terminal electron acceptor of the electron-transport chain in cells undergoing aerobic respiration? a) water b) O2 c) CO2 d) CO e) glucose Answer: b Difficulty: Easy

Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

20) How is the energy used to make ATP via the electron-transport chain generated? a) The energy from electrons bound to reduced coenzymes is used to create a steep electrochemical gradient. b) Electrons bound to NADH are used to generate an H+ ion gradient across the inner mitochondrial membrane. c) Electrons bound to FADH2 are used to generate a proton gradient across the inner mitochondrial membrane. d) Electrons bound to NADH are used to generate a proton gradient across the inner mitochondrial membrane. e) All of these are correct.

Answer: e Difficulty: Medium Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

21) What is the name of the process by which the electron-transport chain generates the electrochemical gradient that drives ATP production in the mitochondrion? a) osmosis b) diffusion c) facilitated diffusion d) chemiosmosis Answer: d Difficulty: Medium Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

22) On average, how many ATPs would be made if 4 NADH and 6 FADH2 molecules donated their high-energy electrons to the mitochondrial electron-transport chain? a) 10 b) 24

c) 12 d) 30 e) 20 Answer: b Difficulty: Medium Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

23) How do mitochondria generate and store the energy used to produce most of the ATP made during aerobic respiration? a) by producing heat b) by generating a heat gradient c) by generating a proton gradient d) by generating a Cl- ion gradient e) by generating a Na+ ion gradient Answer: c Difficulty: Medium Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

24) The formation of ATP by the enzymatic transfer of a phosphate group from a donor molecule to ADP is called ________. a) substrate-level phosphorylation b) oxidative phosphorylation c) cyclic photophosphorylation d) noncyclic photophosphorylation e) indigenous phosphorylation Answer: a Difficulty: Easy Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

25) Which enzyme of the Krebs (TCA) cycle is different from the others with respect to its location and where is it located? a) succinate dehydrogenase, mitochondrial matrix b) malate dehydrogenase, mitochondrial matrix c) succinate dehydrogenase, inner mitochondrial membrane d) malate dehydrogenase, inner mitochondrial membrane e) succinate dehydrogenase, intermembrane space Answer: c Difficulty: Medium Learning Objective: LO 5.2: Outline the steps in glycolysis and the TCA cycle.

Section Reference: Section 5.2: Aerobic Metabolism in the Mitochondrion

26) ___________ exhibit lower electron affinity. a) Strong oxidizing agents b) Strong elucidating agents c) Strong reducing agents d) Weak reducing agents e) Weak eliminating agents Answer: c Difficulty: Hard Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

27) Spontaneous oxidation-reduction (redox) reactions are accompanied by ________. a) a gain of heat energy b) a loss of free energy c) a gain of free energy d) a loss of heat energy e) a gain of heat loss Answer: b Difficulty: Medium

Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

28) Standard redox potential is measured by: a) connecting a reference half cell to a sample half cell via a MgSO4 salt bridge b) detecting proton flow across the salt bridge c) using a voltmeter to measure electron flow d) employing a reference half cell containing a 0.1M H+ solution in equilibrium with H2 gas at 1 atmosphere pressure Answer: c Difficulty: Medium Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

29) Standard redox potential (E0) for a solution is _____________________ a) considered positive if electrons flow from the sample half cell to the reference half cell b) considered negative if electrons flow from the sample half cell to the reference half cell c) calculated in any biochemical comparison of redox potentials between cellular cofactors and other molecules d) measured at absolute zero (0K) Answer: b Difficulty: Medium Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

30) The standard redox potential of the NADP+/NADPH half reaction = -0.324 V. The standard redox potential of the fumarate/succinate half reaction = +0.031 V. What is the voltage change for coupling these redox reactions and in which direction will electrons move? a) 0.355 volts; fumarate will be reduced to succinate and NADPH will be oxidized to NADP+ b) -0.355 volts; fumarate will be reduced to succinate and NADPH will be oxidized to NADP+

c) 0.355 volts; succinate will be reduced to fumarate and NADP+ will be oxidized to NADPH d) -0.355 volts; fumarate will be oxidized to succinate and NADPH will be reduced to NADP+ Answer: a Difficulty: Hard Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

31) What type of electron carrier has a prosthetic group derived from vitamin B2? a) flavoproteins b) cytochromes c) copper atom containing carriers d) ubiquinone e) iron-sulfur proteins Answer: a Difficulty: Easy Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

32) What type of electron carrier has a prosthetic group derived from riboflavin? a) flavoproteins b) cytochromes c) copper atom containing carriers d) ubiquinone e) iron-sulfur proteins Answer: a Difficulty: Easy Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

33) What is another name from for partially reduced ubiquinone? a) ubiquinone b) ubisemiquinone c) ubiquinol d) ubiquinde e) ubiquinate Answer: b Difficulty: Medium Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

34) What is the final electron acceptor in the electron-transport chain of aerobic respiration? a) water b) carbon dioxide c) carbon monoxide d) hydrogen e) oxygen Answer: e Difficulty: Easy Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

35) What is formed when electrons reach the bottom of the mitochondrial electron-transport chain and bind to the final electron acceptor? a) water b) carbon dioxide c) carbon monoxide d) hydrogen e) oxygen Answer: a Difficulty: Medium

Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

36) How do respiratory poisons such as carbon monoxide and cyanide exert their effect? a) They break down oxygen. b) They bind to electrons. c) They bind to the cytochrome oxidase catalytic site. d) They bind to oxygen. e) They denature the inner mitochondrial membrane.

Answer: c Difficulty: Medium Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

37) You are trying to figure out an electron transport pathway including the following electron transport molecules: B, K, T, Q and X. You do so by employing inhibitors for various steps in the process. When you do, you get the following results: Inhibitor Ticin Digitin Estin Lucin

Electron Transport Molecules Trapped in Reduced Form Q&K K T, K, Q & B Q, K & T

What is the order of the molecules (the pathway) in the electron-transport chain suggested by the above data from the most reduced to the least reduced molecule? a) K —> T —> B —> Q —> X b) K —> X —> B —> Q —> T c) K —> Q —> T —> B —> X d) X —> B —> T —> Q —> K e) T —> B —> K —> Q —> X Answer: c Difficulty: Hard

Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

38) Why must the process by which cytochrome oxidase works be efficient? a) If it is not, mitochondria will shrink. b) If it is not, mitochondria will swell and burst. c) If it is not, free radicals will be released. d) If it is not, the mitochondria could denature. e) All of these are correct.

Answer: c Difficulty: Medium Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

39) What is unusual about the way that H+ ions are transported across the inner mitochondrial membrane as compared to the movement of other ions like Na+ and Cl- ions? a) Na+ and Cl- ions must traverse the full distance, but H+ ions materialize on the other side of the membrane. b) Na+ and Cl- ions must traverse the full distance, but H+ ions can hop through a channel by exchanging themselves with other protons found along the pathway. c) Na+ and Cl- ions can hop through a channel by exchanging themselves with other similar ions found along the pathway, but H+ ions must traverse the full distance. d) Na+ and Cl- ions must traverse the full distance, but H+ ions must only go halfway. e) Na+ and Cl- ions must traverse the full distance, but H+ ions must change into neutrons first.

Answer: b Difficulty: Hard Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

40) Of the five types of electron carriers, which has the smallest molecular mass?

a) flavoproteins b) cytochromes c) copper atom containing carriers d) ubiquinone e) iron-sulfur proteins Answer: d Difficulty: Medium Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

41) Of the five types of electron carriers, which has the greatest ratio of iron atoms to electrons carried? a) flavoproteins b) cytochromes c) copper atom containing carriers d) ubiquinone e) iron-sulfur proteins Answer: e Difficulty: Medium Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

42) Of the five types of electron carriers, which has a component located outside the lipid bilayer? a) flavoproteins b) cytochromes c) copper atom containing carriers d) ubiquinone e) iron-sulfur proteins Answer: a Difficulty: Medium

Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

43) Pathways in which H+ ions can "hop" through a channel by exchanging themselves with other protons present along the pathway are called ___________. a) proton conduction wires b) electrical wires c) proton pathways d) proton conveyer belt e) proton conduction pathways and proton wires Answer: e Difficulty: Hard Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

44) The gateway to the electron-transport chain _______________ a) catalyses the transfer of electrons from FADH2 to ubiquinone b) is known as FADH2 dehydrogenase c) catalyses the transfer of electrons from NADH to ubiquinone d) forms ubiquinone in its redox transfer Answer: c Difficulty: Medium Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

45) Which complex found in the electron-transport chain (ETC) consists of just four polypeptides, and which high energy electron carrier shuttles its electrons into the ETC via the complex? a) complex I; NADH b) complex II; NADH

c) complex III; NADH d) complex II; FADH2 e) complex III; FADH2 Answer: d Difficulty: Medium Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

46) Complex III of the electron-transport chain (ETC) moves electrons from______________ to further down the ETC towards the terminal electron acceptor. a) Complex I only b) Complex II only c) Complex I and Complex II d) Complex IV Answer: c Difficulty: Medium Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

47) What percentage of blood oxygen is dissolved in the liquid plasma component? a) 0.5% b) 1% c) 2% d) 10% Answer: c Difficulty: Easy Learning Objective: LO 5.4: Describe the molecular basis for measurement of blood oxygen.

Section Reference: Section 5.4: Engineering Linkage: Measuring Blood Oxygen

48) In the Clark electrode system, oxygen levels are measured by:

a) placing metal strips of platinum and silver in an electrolyte system containing sodium bromide b) placing metal strips of platinum and copper in an electrolyte system containing potassium chloride c) detecting temperature changes across the electrodes induced by redox reactions d) detecting voltage changes when redox reactions involving oxygen, two metals and chloride ions take place.

Answer: d Difficulty: Hard Learning Objective: LO 5.4: Describe the molecular basis for measurement of blood oxygen.

Section Reference: Section 5.4: Engineering Linkage: Measuring Blood Oxygen

49) Which statement regarding the Clark-type transcutaneous oxygen sensor is INCORRECT? a) An electrode is placed on the patient’s skin to allow oxygen diffusion from the bloodstream into the electrode. b) Oxygen movement through the electrode is assisted by using a small heating element. c) The sensor works better on adult patients than young babies. d) The skin of adults is less permeable to oxygen.

Answer: c Difficulty: Medium Learning Objective: LO 5.4: Describe the molecular basis for measurement of blood oxygen.

Section Reference: Section 5.4: Engineering Linkage: Measuring Blood Oxygen

50) A pulse oximeter has all of the characteristics detailed below EXCEPT: a) two light emitting diodes, one emitting at 660 nm and one at 900 nm b) measurement of light transmission at two wavelengths permits evaluation of the proportion of hemoglobin molecules which are carrying oxygen c) the oximeter can be easily attached to a finger or earlobe d) skin thickness and pigmentation do not influence the accuracy of the data derived from the oximeter Answer: d Difficulty: Medium Learning Objective: LO 5.4: Describe the molecular basis for measurement of blood oxygen.

Section Reference: Section 5.4: Engineering Linkage: Measuring Blood Oxygen

51) Red light is emitted at a wavelength of: a) 900nm b) 660nm c) 330 nm d) 250 nm Answer: b Difficulty: Easy Learning Objective: LO 5.4: Describe the molecular basis for measurement of blood oxygen.

Section Reference: Section 5.4: Engineering Linkage: Measuring Blood Oxygen

52) Infra-red light is emitted at a wavelength of: a) 900nm b) 660nm c) 330 nm d) 250 nm Answer: a Difficulty: Easy Learning Objective: LO 5.4: Describe the molecular basis for measurement of blood oxygen.

Section Reference: Section 5.4: Engineering Linkage: Measuring Blood Oxygen

53) Electrochemical gradients have both _________ and __________ component. a) a concentration, an acidic b) an acidic, an electrical c) a concentration, a basic d) a concentration, an electrical e) an acidic, a basic Answer: d Difficulty: Easy Learning Objective: LO 5.5: Explain how translocation of protons can establish a proton-motive force.

Section Reference: Section 5.5 Establishment of a Proton-Motive Force

54) Why did dinitrophenol (DNP) kill patients who took the drug to help them lose weight? a) It caused temperatures of the patients to get too high. b) It blocked hemoglobin synthesis. c) It caused an infection. d) It caused total paralysis. e) It prevented the patients from breathing.

Answer: a Difficulty: Easy Learning Objective: LO 5.5: Explain how translocation of protons can establish a proton-motive force.

Section Reference: Section 5.5 Establishment of a Proton-Motive Force

55) What is the purpose of uncoupling proteins in mammalian brown adipose tissue? a) They give the tissue its color. b) They help the tissue expand and contract when needed. c) They function as a source of heat production during exposure to cold temperatures. d) They allow the production of a larger number of ATPs per glucose. e) They allow muscles to contract more efficiently.

Answer: c Difficulty: Medium Learning Objective: LO 5.5: Explain how translocation of protons can establish a proton-motive force.

Section Reference: Section 5.5 Establishment of a Proton-Motive Force

56) In the electrochemical gradient established in mitochondria: a) 10% of the free energy generated by the proton-motive force is derived from the voltage gradient and 90% is derived from the chemical gradient b) 80% of the free energy generated by the proton-motive force is derived from the voltage gradient and 20% is derived from the chemical gradient c) 59% of the free energy generated by the proton-motive force is derived from the voltage gradient and 41% is derived from the chemical gradient

d) 65% of the free energy generated by the proton-motive force is derived from the voltage gradient and 35% is derived from the chemical gradient Answer: b Difficulty: Medium Learning Objective: LO 5.5: Explain how translocation of protons can establish a proton-motive force.

Section Reference: Section 5.5 Establishment of a Proton-Motive Force

57) The F0 base of ATP synthase serves as ______. a) an enzyme that synthesizes ATP b) an enzyme that hydrolyzes ATP c) a channel that conducts protons from the intermembrane space back to the matrix d) a channel that conducts protons from the matrix back to the intermembrane space e) a proton pump Answer: c Difficulty: Medium Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

58) The energy released by proton movement through ATP synthase ___________. a) directly phosphorylates ADP to ATP b) increases the binding affinity of the active site for the ATP product c) directly phosphorylates ATP to ADP d) decreases the binding affinity of the active site for the ATP product e) directly phosphorylates AMP to ATP Answer: d Difficulty: Medium Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

59) The energy expended during the formation of ATP by ATP synthase is required to _______. a) attach the phosphate group to ADP b) attach the phosphate group to ATP c) release the tightly bound ATP from the ATP synthase catalytic site d) attach the tightly bound ATP to the ATP synthase catalytic site e) move protons against their gradient Answer: c Difficulty: Medium Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

60) How many catalytic sites does ATP synthase possess? a) 1 b) 2 c) 3 d) 6 e) 4 Answer: c Difficulty: Medium Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

61) The three catalytic sites of ATP synthase ___________. a) have different substrate binding affinities b) have different product binding affinities c) at any one time are present in different conformations d) pass sequentially through their three different conformations e) all of these are correct Answer: e Difficulty: Medium

Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

62) The L conformation of an ATP synthase catalytic site ________. a) has a very low affinity for nucleotides b) loosely binds AMP and an inorganic phosphate group c) has a very low affinity for proteins d) binds ATP, ADP and inorganic phosphate groups tightly e) loosely binds ADP and an inorganic phosphate group Answer: e Difficulty: Medium Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

63) It has been shown that one part of ATP synthase rotates relative to another part of the enzyme, a phenomenon called___________. a) turning catalysis b) revolutionary catalysis c) rotational catalysis d) rotatalysis e) revolalysis Answer: c Difficulty: Easy Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

64) What drives the rotation of the F1 head of ATP synthase? a) proton movement from intermembrane space to the matrix b) proton movement from the matrix to the intermembrane space c) ATP hydrolysis

d) ATP condensation e) proton movement from the cytoplasm to the intermembrane space Answer: a Difficulty: Easy Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

65) Which of the statements below served as evidence that rotational catalysis occurs in ATP synthase? a) movement was directly observed in the electron microscope b) a fluorescently labeled actin filament attached to the enzyme's ɤ subunit was seen to rotate when ATP was added to the enzyme which was fixed to a cover slip c) circular dichroism revealed the movement d) an inhibitor stopped the enzyme movement e) atomic force microscopy showed the movement Answer: b Difficulty: Medium Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

66) In the experiment that demonstrated that rotational catalysis occurs, a fluorescently labeled actin filament attached to the ATP synthase enzyme's ɤ subunit was seen to rotate when ATP was added to the enzyme, which was fixed to a cover slip. With each step in the rotational catalysis, how much could the actin filament be seen to rotate? a) 0° b) 360° c) 120° d) 90° e) 3° Answer: c Difficulty: Hard

Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

67) What energy source other than ATP hydrolysis do mitochondria, unlike most other organelles, routinely use to power their activities? a) ADP hydrolysis b) proton-motive force c) Na+ ion gradient d) K+ ion gradient e) Ca2+ gradient Answer: b Difficulty: Easy Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

68) Which activity below is NOT thought to be driven by the proton-motive force? a) formation of the spindle b) ADP and inorganic phosphate uptake into the mitochondrion in exchange for ATP and H+, respectively c) uptake of Ca2+ ions into the mitochondrion d) the events of mitochondrial fusion e) uptake of specifically targeted proteins into the mitochondrion from the matrix Answer: a Difficulty: Easy Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

69) Which molecule below plays a key role in regulating the rate of glycolysis and Krebs cycle by regulating the activity of key enzymes? a) ADP

b) inorganic phosphate c) ATP d) molecular oxygen e) gaseous nitrogen Answer: c Difficulty: Easy Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

70) Which molecule below plays a key role in regulating respiratory rate in the mitochondrion? a) ADP b) inorganic phosphate c) ATP d) molecular oxygen e) gaseous nitrogen Answer: a Difficulty: Easy Learning Objective: LO 5.6: Describe how ATP synthase and the proton gradient drive the phosphorylation of ADP. Section Reference: Section 5.6: The Machinery for ATP Formation

71) An unusual type of phospholipid called ___________ is found in the myelin sheath that insulates brain axons; abnormalities in the synthesis of this phospholipid can lead to severe neurological dysfunction. a) plasmins b) sphingolipids c) plasmalogens d) insulins e) luciferases Answer: c Difficulty: Easy Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

72) Which of the following is true of peroxisomes? a) Peroxisomes contain more than 50 enzymes involved in diverse activities. b) Peroxisomes contain enzymes that oxidize very-long-chain fatty acids. c) Peroxisomes contain the enzyme luciferase, which generates the light emitted by fireflies. d) All of these are correct.

Answer: d Difficulty: Medium Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

73) What properties do mitochondria share with peroxisomes? a) Both form by splitting from preexisting organelles, using some of the same proteins to accomplish the feat. b) Both import preformed proteins from the cytosol. c) Both engage in similar types of oxidative metabolism. d) At least one enzyme is found in the mitochondria of some mammals and the peroxisomes of others. e) All of these are correct.

Answer: e Difficulty: Medium Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

74) Peroxisomal enzymes possess all of the characteristics listed EXCEPT: a) produce hydrogen peroxide b) break down hydrogen peroxide c) include catalase d) may sometimes be located in peroxisomes Answer: a

Difficulty: Medium Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

75) X-linked adrenoleukodystropy is a condition with all of the following characteristics EXCEPT: a) onset in mid-childhood b) abnormal functioning of a mitochondrial enzyme c) symptoms including adrenal gland failure and neurological disorders d) defects in the transportation of very long chain fatty acids Answer: b Difficulty: Medium Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

76) Why would the individual described in Rudolf Luft’s 1962 case study of mitochondrial dysfunction possibly be exercise intolerant? a) her mitochondria produce excess ATP, making muscle contraction difficult b) her mitochondria produce excess ADP, making muscle contraction difficult c) her mitochondria produce little ATP, making muscle contraction difficult d) her mitochondria produce little ADP, making muscle contraction difficult Answer: c Difficulty: Medium Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

77) Why might large aggregates of mitochondria be located in the muscle cells of individuals with ragged red fiber disease? a) the poorly functioning organelles proliferate in an attempt to meet cellular energy needs, just as they would for an athlete in training b) the abnormal mitochondria are using all ATP they produce to replicate at an abnormally high rate

c) the mitochondria are excessively fragile and are damaged during biopsy, so that counting reveals an unrealistic assessment of their numbers d) all choices are implausible Answer: a Difficulty: Hard Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

78) From which parent are mitochondria inherited? a) mitochondria are derived from the spermatid cytosol b) mitochondria are derived from the egg cytoplasm c) mitochondria are derived from both egg and sperm at the time of fertilization d) mitochondria arise only once the zygote begins to develop independently as a diploid life form.

Answer: b Difficulty: Medium Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

79) If a couple had one child with ragged red fiber disease and wished to have a healthy second child, mitochondrial replacement therapy might be discussed as an option. Technically, how many parents would the child possess after such a treatment? a) 1 b) 2 c) 3 d) 4 Answer: c Difficulty: Medium Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

80) Mitochondrial DNA suffers a higher mutation rate than nuclear DNA by a factor of:

a) 2 b) 10 c) 50 d) 1500 Answer: c Difficulty: Easy Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

81) What disease is associated with dysfunctional Complex I activity within mitochondria? a) ragged red fiber disease b) compulsive behaviors such as drug addiction c) Parkinson’s disease d) Zellweger’s syndrome Answer: c Difficulty: Medium Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

82) Which region of the brain has been shown to suffer an increased mutation rate in patients with Parkinson’s disease, according to some studies? a) cerebral cortex b) olfactory lobe c) cerebellum d) substantia nigra Answer: d Difficulty: Easy Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

83) Which organelle below is NOT found in both plants and animals?

a) cell membrane b) mitochondria c) peroxisomes d) glyoxysomes e) vacuoles Answer: d Difficulty: Medium Learning Objective: LO 5.8: Outline the functions of glyoxysomes in seed germination.

Section Reference: Section 5.8: Green Cells: Glyoxysomes

84) A plant seedling is stated to convert stored fatty acids into carbohydrates using the glyoxylate cycle. Based upon the brief description provided in Section 5.8 of the text, which other metabolic pathway does the glyoxylate cycle resemble in terms of its substrates? a) glycolysis b) electron-transport chain c) Krebs cycle d) fermentation Answer: c Difficulty: Hard Learning Objective: LO 5.8: Outline the functions of glyoxysomes in seed germination.

Section Reference: Section 5.8: Green Cells: Glyoxysomes

85) Which plant is likely to have the most active glyoxylate cycle enzymes during germination? a) potato b) rose c) peanut d) wheat Answer: c Difficulty: Medium Learning Objective: LO 5.8: Outline the functions of glyoxysomes in seed germination.

Section Reference: Section 5.8: Green Cells: Glyoxysomes

Question Type: Multiple Select

86) The balance between fusion and fission is likely a major determinant of which properties of mitochondria? (Select all correct choices) a) number b) length c) color d) degree of interconnection Answer: a, b, d Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

Question Type: Multiple Select

87) When fusion of mitochondria becomes more frequent than fission, the mitochondria tend to become __________. (Select all correct responses) a) more elongated b) more interconnected c) more numerous d) more distinct Answer: a, b Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

Question Type: Multiple Select

88) When fission of mitochondria becomes more frequent than fusion, the mitochondria tend to become __________. (Select all correct responses) a) more elongated b) more interconnected c) more numerous d) more distinct Answer: c, d Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

Question Type: Multiple Select

89) Which of the following regulate intracellular levels of Ca2+ ions? (Select all correct choices) a) Golgi apparatus b) ribosomes c) endoplasmic reticulum d) mitochondria Answer: c, d Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

Question Type: Multiple Select

90) Which lipid is known for playing an important role in facilitating the activity of proteins involved in ATP synthesis? (Select all correct choices) a) diphosphatidylglycerol

b) phosphatidyl inositol c) phosphatidic acid d) cardiolipin Answer: a, d Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

Question Type: Multiple Select

91) What evidence suggests that the inner mitochondrial membrane has evolved from a bacterial plasma membrane? (Select all correct choices) a) the presence of porins in both membranes b) the virtual absence of cholesterol from both membranes c) both membranes being rich in cardiolipin d) both membranes being rich in diphosphatidylglycerol Answer: b, c, d Difficulty: Medium Learning Objective: LO 5.1: Describe the origin, structure, and functions of the membranes and matrix of the mitochondrion.

Section Reference: Section 5.1 Mitochondrial Structure and Function

Question Type: Multiple Select

92) Of the five types of electron carriers, which accept and donate electrons only? correct choices) a) flavoproteins b) cytochromes c) copper atom containing carriers d) ubiquinone e) iron-sulfur proteins

(Select all

Answer: b, c, e Difficulty: Hard Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

Question Type: Multiple Select

93) Of the five types of electron carriers, which accept and donate both protons and electrons?

(Select all correct choices) a) flavoproteins b) cytochromes c) copper atom containing carriers d) ubiquinone e) iron-sulfur proteins Answer: a, d Difficulty: Hard Learning Objective: LO 5.3: Explain how the transport of electrons down the respiratory chain leads to the formation of a proton gradient.

Section Reference: Section 5.3 The Role of Mitochondria in the Formation of ATP

Question Type: Multiple Select

94) A plant seedling converts stored fatty acids into carbohydrates. Which metabolic pathway(s) will be used to generate energy from the lipid-derived 2 carbon intermediates?

(Select all correct choices) a) glycolysis b) electron-transport chain c) Krebs cycle d) glyoxylate cycle Answer: b, d

Difficulty: Medium Learning Objective: LO 5.8: Outline the functions of glyoxysomes in seed germination.

Section Reference: Section 5.8: Green Cells: Glyoxysomes

Question Type: Multiple Select

95) If an individual has an inherited mitochondrial gene mutation, from which parental source did it originate? (Select all correct choices) a) paternally derived nuclear chromosome b) maternally derived nuclear chromosome c) paternally derived mitochondrial gene d) maternally derived mitochondrial gene Answer: b, d Difficulty: Hard Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

Question Type: Multiple Select

96) Why is mitochondrial DNA more mutation prone than nuclear DNA? choices)

(Select all correct

a) there are more mitochondrial genomes than nuclear genomes, creating a higher probability of mutation b) nuclear DNA is shielded by a double membrane whereas mitochondia are surrounded by a single membrane layer c) nuclear DNA is more likely to have error repair than mitochondrial DNA d) more reactive oxygen species are generated within mitochondria than within the nucleus Answer: c, d Difficulty: Hard Learning Objective: LO 5.7: Describe the role of peroxisomes in the cell.

Section Reference: Section 5.7: Peroxisomes

Question Type: Multiple Select

97) Which organelle(s) have been found to contain catalase? (Select all correct choices) a) mitochondria b) glyoxysomes c) peroxisomes d) lysosomes Answer: b, c Difficulty: Easy Learning Objective: LO 5.8: Outline the functions of glyoxysomes in seed germination.

Section Reference: Section 5.8: Green Cells: Glyoxysomes

Question Type: Multiple Select

98) Which organelle(s) have been found to contain catalase? (Select all correct choices) a) mitochondria b) glyoxysomes c) peroxisomes d) chloroplasts Answer: b, c Difficulty: Easy Learning Objective: LO 5.8: Outline the functions of glyoxysomes in seed germination.

Section Reference: Section 5.8: Green Cells: Glyoxysomes

Question Type: Multiple Select

99) Which organelle(s) have been found to assist growing plants meet their energy needs?

(Select all correct choices)

a) mitochondria b) glyoxysomes c) peroxisomes d) chloroplasts Answer: a, b, c, d Difficulty: Medium Learning Objective: LO 5.8: Outline the functions of glyoxysomes in seed germination.

Section Reference: Section 5.8: Green Cells: Glyoxysomes

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 6

Question Type: Multiple Choice

1) The raw materials that the earliest forms of life on Earth used for nutrients were produced ______. a) artificially b) biotically c) abiotically d) supernaturally e) quickly Answer: c Difficulty: Easy Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

2) Organisms that depend on an external source of organic compounds are called _________. a) autotrophs b) heterotrophs c) chemotrophs d) phototrophs e) externotrophs Answer: b Difficulty: Easy Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

3) Why was the number of heterotrophs on primitive Earth likely to have initially been severely restricted? a) The spontaneous production of organic molecules occurs very slowly. b) The spontaneous production of organic molecules occurs very quickly. c) The early heterotrophs could not reproduce. d) The early heterotrophs reproduced too quickly. e) Organic molecules spontaneously broke down keeping their amounts low.

Answer: a Difficulty: Easy Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

4) Organisms that can survive on carbon dioxide as their principal carbon source are called ______. a) autotrophs b) heterotrophs c) chemotrophs d) phototrophs e) externotrophs Answer: a Difficulty: Easy Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

5) Organisms that use the energy stored in inorganic molecules, like ammonia, hydrogen sulfide, or nitrites, to convert carbon dioxide to organic molecules like carbohydrates and proteins are called ___________. a) chemoautotrophs b) chemoheterotrophs c) photoautotrophs d) photoheterotrophs e) didliotrophs

Answer: a Difficulty: Easy Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

6) Organisms that use the radiant energy of the sun to convert carbon dioxide to organic molecules like carbohydrates and proteins are called _____. a) chemoautotrophs b) chemoheterotrophs c) photoautotrophs d) photoheterotrophs e) didliotrophs Answer: c Difficulty: Easy Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

7) Photoautotrophs include _________. a) plants b) eukaryotic algae c) various flagellated protists d) members of several groups of prokaryotes e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

8) Which metabolic process below do all eukaryotic green algae and higher plants have in common?

a) glycolysis b) photosynthesis c) transcription d) translation e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

9) The earliest photosynthetic organisms on Earth probably used __________ as an electron source for photosynthesis. a) water b) hydrogen sulfide c) hydrogen sulfite d) carbon dioxide e) carbohydrates Answer: b Difficulty: Medium Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

10) Why are organisms that presently use hydrogen sulfide as an electron source limited in their distribution and importance? a) It is more efficient. b) They are smaller. c) Hydrogen sulfide is abundant and widespread. d) Hydrogen sulfide is neither abundant nor widespread. e) In the current environment, hydrogen sulfide combines with silicon dioxide, inactivating it.

Answer: d Difficulty: Easy

Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

11) How did the evolution of photosynthesis set the stage for the evolution of aerobic respiration? a) Photosynthesis produces a waste product (carbon dioxide) that led to the evolution of aerobic respiration. b) Photosynthesis produces a waste product (oxygen) that led to the evolution of aerobic respiration. c) Photosynthesis uses carbon monoxide in the atmosphere. d) Photosynthesis produces a waste product (sulfur) that led to the evolution of aerobic respiration. e) Photosynthesis inhibits glycolysis.

Answer: b Difficulty: Medium Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

12) A direct advantage of using water as an electron source for photosynthesis is that organisms _________. a) can live in fewer habitats than they could previously b) can get larger c) are able to live in a much more diverse array of habitats d) can be smaller e) can be rehydrated more readily Answer: c Difficulty: Easy Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

13) It is much _____ to pull electrons from water than hydrogen sulfide, since the sulfur atom in hydrogen sulfide has a much ______ affinity for its electrons than the oxygen atom in water. a) harder, lower b) harder, higher c) easier, lower d) easier, higher e) easier, more moderate Answer: a Difficulty: Hard Learning Objective: LO 6.1: Explain the roles of autotrophs, cyanobacteria, and the chloroplast in the origin of photosynthesis.

Section Reference: Section 6.1: The Origin of Photosynthesis

14) Chloroplasts were discovered as the site of photosynthesis in an ingenious experiment.

What was it? a) Oxygen could be seen as it was produced in chloroplasts. b) Chloroplasts were seen to swell in the presence of sunlight. c) Spirogyra in the dark shrank and their chloroplast disappeared. d) When Spirogyra was illuminated, actively moving bacteria gathered outside the cell near its large ribbon-like chloroplast to use the oxygen produced there for aerobic respiration.

Answer: d Difficulty: Easy Learning Objective: LO 6.2: Describe the structure of a chloroplast.

Section Reference: Section 6.2: Chloroplast Structure

15) The outer membrane of the chloroplast contains _____ like the outer membrane of ______. a) carbohydrates, mitochondria b) carbohydrates, peroxisomes c) several different porins, mitochondria d) mitochondria, porins e) several different porins, the nucleus Answer: c Difficulty: Easy

Learning Objective: LO 6.2: Describe the structure of a chloroplast.

Section Reference: Section 6.2: Chloroplast Structure

16) The chloroplast internal membrane is organized into flattened membranous sacs called _________; they, in turn, are arranged in orderly stacks called _______ that contain energy-transducing machinery. a) thylakoids, grana b) grana, thylakoids c) thylakoids, stroma thylakoids d) thylakoids, grana thylakoids e) grana thylakoids, thylakoids Answer: a Difficulty: Easy Learning Objective: LO 6.2: Describe the structure of a chloroplast.

Section Reference: Section 6.2: Chloroplast Structure

17) Where are the enzymes that synthesize carbohydrates located? a) grana b) thylakoids c) lumen d) stroma e) chloroplast envelope Answer: d Difficulty: Medium Learning Objective: LO 6.2: Describe the structure of a chloroplast.

Section Reference: Section 6.2: Chloroplast Structure

18) Flattened membranous structures that connect the thylakoids of different grana are known as ______. a) grana thylakoids b) stroma thylakoids c) grana d) lumen

e) stroma Answer: b Difficulty: Medium Learning Objective: LO 6.2: Describe the structure of a chloroplast.

Section Reference: Section 6.2: Chloroplast Structure

19) Which of the following is NOT a usual component found in the stroma? a) tRNAs b) prokaryote-like ribosomes c) circular DNA d) linear DNA e) many different polypeptides Answer: d Difficulty: Medium Learning Objective: LO 6.2: Describe the structure of a chloroplast.

Section Reference: Section 6.2: Chloroplast Structure

20) Thylakoid membranes have ___________. a) high protein content b) relatively plentiful phospholipids c) a low percentage of galactose-containing glycolipids d) low protein content Answer: a Difficulty: Medium Learning Objective: LO 6.2: Describe the structure of a chloroplast.

Section Reference: Section 6.2: Chloroplast Structure

21) Thylakoid membranes are characterized by possessing ___________. a) low protein content b) relatively plentiful phospholipids c) a high percentage of galactose-containing glycolipids

d) low DNA content Answer: c Difficulty: Medium Learning Objective: LO 6.2: Describe the structure of a chloroplast.

Section Reference: Section 6.2: Chloroplast Structure

22) The non-pigmented precursors of chloroplasts are called __________. a) prechloros b) preplastids c) proplastids d) prochloroplasts e) prechloroplasts Answer: c Difficulty: Easy Learning Objective: LO 6.2: Describe the structure of a chloroplast.

Section Reference: Section 6.2: Chloroplast Structure

23) What do sulfur bacteria use as a source of electrons in photosynthesis? a) hydrogen sulfide b) water c) hydrogen sulfite d) carbon dioxide e) glucose Answer: a Difficulty: Medium Learning Objective: LO 6.3: Identify the roles in photosynthesis of the light-dependent reactions and the light-independent reactions.

Section Reference: Section 6.3: An Overview of Photosynthetic Metabolism

24) You expose algae to CO2 that contains radiolabeled oxygen. Where does the radiolabeled oxygen end up after photosynthesis?

a) in water b) in oxygen c) in carbon dioxide d) in carbohydrates e) in carbon monoxide Answer: d Difficulty: Hard Learning Objective: LO 6.3: Identify the roles in photosynthesis of the light-dependent reactions and the light-independent reactions.

Section Reference: Section 6.3: An Overview of Photosynthetic Metabolism

25) What is the plant cell's primary source of reducing power? a) CO2 b) ADP c) ATP d) NAD e) NADPH Answer: e Difficulty: Medium Learning Objective: LO 6.3: Identify the roles in photosynthesis of the light-dependent reactions and the light-independent reactions.

Section Reference: Section 6.3: An Overview of Photosynthetic Metabolism

26) What group of organisms is thought to be responsible for converting about 500 trillion kg of CO2 to carbohydrate each year? a) plant life as a whole b) phytoplankton c) fungi d) bacteria e) mosses Answer: a Difficulty: Easy

Learning Objective: LO 6.3: Identify the roles in photosynthesis of the light-dependent reactions and the light-independent reactions.

Section Reference: Section 6.3: An Overview of Photosynthetic Metabolism

27) What part of the chlorophyll molecule absorbs light? a) the phytol chain b) the porphyrin ring c) the iron containing heme group d) the polypeptide backbone Answer: b Difficulty: Easy Learning Objective: LO 6.4: Compare the structures, absorption, and functions of chlorophylls and carotenoids.

Section Reference: Section 6.4: The Absorption of Light

28) What metal atom is part of the chlorophyll porphyrin ring? a) magnesium b) manganese c) platinum d) iron e) aluminum Answer: a Difficulty: Easy Learning Objective: LO 6.4: Compare the structures, absorption, and functions of chlorophylls and carotenoids.

Section Reference: Section 6.4: The Absorption of Light

29) Which type of chlorophyll is only found in brown algae, diatoms and certain protozoa? a) chlorophyll a b) chlorophyll b c) chlorophyll c d) bacteriochlorophyll

e) carotenoids Answer: c Difficulty: Medium Learning Objective: LO 6.4: Compare the structures, absorption, and functions of chlorophylls and carotenoids.

Section Reference: Section 6.4: The Absorption of Light

30) Which type of chlorophyll is only found in red algae? a) chlorophyll a b) chlorophyll b c) chlorophyll c d) chlorophyll d e) carotenoids Answer: d Difficuly: Medium Learning Objective: LO 6.4: Compare the structures, absorption, and functions of chlorophylls and carotenoids.

Section Reference: Section 6.4: The Absorption of Light

31) Which type of chlorophyll is only found in green and purple bacteria? a) chlorophyll a b) chlorophyll b c) chlorophyll c d) bacteriochlorophyll e) carotenoids Answer: d Difficulty: Medium Learning Objective: LO 6.4: Compare the structures, absorption, and functions of chlorophylls and carotenoids.

Section Reference: Section 6.4: The Absorption of Light

32) Carotenoids ________.

a) absorb primarily blue light b) absorb primarily green light c) reflect orange and red light d) reflect yellow light e) all of these are correct choices Answer: e Difficulty: Medium Learning Objective: LO 6.4: Compare the structures, absorption, and functions of chlorophylls and carotenoids.

Section Reference: Section 6.4: The Absorption of Light

33) You are studying mutant algal cells that lack carotenoids. You raise them in an aerobic environment. They do not survive. Why? a) They cannot absorb any light. b) They reflect all colors of light. c) They dissipate aerobic environments. d) They transfer excess energy to O2 making ultrareactive singlet oxygen that can destroy biological molecules and cause cell death. e) The lack of carotenoids causes the chloroplast membranes to disintegrate.

Answer: d Difficulty: Hard Learning Objective: LO 6.4: Compare the structures, absorption, and functions of chlorophylls and carotenoids.

Section Reference: Section 6.4: The Absorption of Light

34) Formation of chromoplasts from chloroplasts is an adaptation designed to assist in: a) pollination b) seed dispersal c) protection from herbivorous animals d) protection from herbicides e) energy storage Answer: b Difficulty: Easy

Learning Objective: LO 6.5: Identify the functions of chromoplasts.

Section Reference: Section 6.5: Green Cells: Chromoplasts

35) The primary role of amyloplasts in a plant cell is __________________________ a) pollination b) seed dispersal c) protection from herbivorous animals d) protection from herbicides e) energy storage Answer: e Difficulty: Easy Learning Objective: LO 6.5: Identify the functions of chromoplasts.

Section Reference: Section 6.5: Green Cells: Chromoplasts

36) One difference between chromoplasts and gerontoplasts is that: a) the gerontoplast produces more chlorophyll molecules. b) the chromoplast produces more chlorophyll molecules, c) the gerontoplast produces more carotenoid molecules. d) the chromoplast produces more carotenoid molecules.

Answer: d Difficulty: Medium Learning Objective: LO 6.5: Identify the functions of chromoplasts.

Section Reference: Section 6.5: Green Cells: Chromoplasts

37) What is the minimum number of photons needed to make one molecule of O2 during photosynthesis? a) 2 b) 4 c) 6 d) 8 e) 16 Answer: d

Difficulty: Easy Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

38) About how many chlorophyll molecules are found in a single photosynthetic unit and how many of those chlorophyll molecules actually transfer electrons to an electron acceptor? a) 300, 200 b) 300, 1 c) 300, 300 d) 2400, 300 e) 2, 1 Answer: b Difficulty: Medium Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

39) As energy passes through a photosynthetic unit, it is transferred to a pigment molecule that absorbs at an______ wavelength, so energy is _____ and the nature of future transfers becomes restricted. a) equal or longer, lost b) equal or longer, gained c) equal or shorter, gained d) equal or shorter, lost e) equal, the same Answer: a Difficulty: Medium Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

40) Photosynthetic light absorption occurs in large pigment-protein complexes called __________. a) pigmentoses

b) pigmentosystems c) antennoids d) photoids e) photosystems Answer: e Difficulty: Easy Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

41) The shared properties of the two photosystems (I and II) with respect to protein composition and overall architecture suggest that __________. a) both absorb exactly the same wavelength of light b) all photosynthetic reaction centers have evolved from a common ancestral structure that has been conserved for a long time (more than 3 billion years) c) all photosynthetic reaction centers have their own unique ancestor d) all photosynthetic reaction centers have evolved separately within the last 100,000 years e) all photosynthetic reaction centers evolved from unrelated structures Answer: b Difficulty: Medium Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

42) The PSII reaction center, also known as P680, _____________. a) absorbs light most strongly at 680 nm b) reflects light most strongly at 680 nm c) reflects light most strongly at 700 nm d) absorbs light most strongly at 700 nm Answer: a Difficulty: Easy Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

43) The LHCII complex binds pigments and holds them in close contact with one another.

What is the advantage of the close contact between the pigments? a) facilitates rapid energy transfer toward the photosystem interior b) facilitates rapid energy transfer toward the photosystem exterior c) helps with fluorescence d) helps prevent denaturation e) facilitates renaturation Answer: a Difficulty: Hard Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

44) The excited PSII reaction-center pigment (P680+) transfers a single photoexcited electron to a closely associated, chlorophyll-like molecule called _________. a) theophyllin b) carotene c) pheophytin d) xanthophylls e) succinate dehydrogenase Answer: c Difficulty: Easy Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

45) To what type of molecule does pheophytin pass its photo-excited electron? a) theophyllin b) plastoquinone c) another pheophytin d) xanthophylls e) succinate dehydrogenase Answer: b Difficulty: Easy

Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

46) The light-driven splitting of a water molecule is known as _______. a) hydrolysis b) photonization c) photolysis d) condensation e) dehydration Answer: c Difficulty: Easy Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

47) A cluster of what kind of ions is responsible for passing electrons one-at-a-time to the nearby P680+ in the reaction center? a) a cluster of 5 iron ions b) a cluster of 4 manganese ions and one calcium ion c) a cluster of one magnesium ion and 4 calcium ions d) a cluster of 5 copper ions e) a cluster of 5 manganese ions Answer: b Difficulty: Medium Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

48) What waste product of photolysis is released to the environment? a) carbon dioxide b) water c) oxygen d) ammonia e) precipitated manganese

Answer: c Difficulty: Easy Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

49) Which molecule conveys protons from the chloroplast stroma into the thylakoid lumen? a) cytochrome b6f b) plastocyanin c) phytochrome d) cytochrome c e) oxygen Answer: a Difficulty: Medium Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

50) Which molecule carries electrons to the luminal side of the positively charged PSI reaction center where they are transferred to pigment P700+, the positively charged reaction-center pigment of PSI? a) cytochrome b6f b) plastocyanin c) phytochrome d) cytochrome c e) oxygen Answer: b Difficulty: Easy Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

51) ___________is a small, water-soluble, iron-sulfur protein that transfers electrons to NADP+ to form NADPH. a) Ferritin

b) Sulfotriene c) Sulfate d) Ferredoxin e) Sulferritin Answer: d Difficulty: Medium Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

52) What is the mechanism by which the herbicides diuron, atrazine and terbutryn are able to kill plants? a) They bind to the manganese ions of chlorophyll. b) They block electron transport through PSII. c) They act as competitive inhibitors of reduced plastiquinone binding to chlorophyll a. d) They act as noncompetitive inhibitors of reduced plastiquinone binding to the D1 protein of PSII. e) They bind to hemoglobin.

Answer: b Difficulty: Medium Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

53) What is the mechanism of action by which the herbicide paraquat kills plants? a) It competes with ferredoxin for electrons from the PSI reaction center. b) It interferes with PSI function. c) Electrons attached to paraquat are used to reduce oxygen, generating highly reactive oxygen radicals. d) It leads to the production of substances that damage the chloroplasts and kill the plant. e) All of these are correct.

Answer: e Difficulty: Medium Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

54) How does paraquat destroy human tissue? a) It competes with ferredoxin for electrons from the PSI reaction center. b) It interferes with PSI function. c) Electrons attached to paraquat are used to reduce nitrogen, generating highly reactive nitrogen radicals. d) It leads to the production of substances that damage and kill the tissue. e) It generates oxygen radicals using electrons diverted from complex I of the respiratory chain.

Answer: e Difficulty: Medium Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

55) How does high intensity light supposedly damage PSII? a) If overexcited, PSII becomes highly acidic. b) If overexcited, PSII becomes highly basic. c) If overexcited, PSII can damage PSI. d) If overexcited, PSII can form toxic oxygen species. e) If overexcited, PSII dissociates.

Answer: d Difficulty: Easy Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

56) In chloroplasts, a proton gradient is established with a higher concentration of protons found in the ______ and a lower concentration in the ______. a) thylakoid lumen, intermembrane space b) intermembrane space, thylakoid lumen c) thylakoid lumen, stroma d) stroma, thylakoid lumen e) intermembrane space, matrix Answer: c

Difficulty: Medium Learning Objective: LO 6.7: Describe two mechanisms of ATP synthesis in the chloroplast.

Section Reference: Section 6.7: Photophosphorylation

57) High intensity light has a negative effect on photosynthesis; in fact, too much light can diminish photosynthetic output. This phenomenon is known as _______. a) photousurpation b) photodiminishment c) photoinhibition d) photosynthetic diminishment e) disinhibition Answer: c Difficulty: Easy Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

58) What part of PSII appears to suffer most of the damage from high intensity light? a) the reaction center photopigment b) the D1 polypeptide of PSII c) the electrons d) NADPH e) both the D1 polypeptide of PSII and NADPH Answer: b Difficulty: Medium Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

59) How does the production of ATP in chloroplasts differ from production in mitochondria? a) The protons move into the stroma of chloroplasts and out of the stroma of mitochondria. b) It relies on electrochemical potential in mitochondria and on pH gradient in chloroplasts. c) It relies on pH gradient in mitochondria and electrochemical potential in chloroplasts. d) The protons move into the intermembrane space in chloroplasts and into the thylakoid lumen in mitochondria.

e) The protons move into the matrix in mitochondria and into the cytoplasm in chloroplasts.

Answer: b Difficulty: Hard Learning Objective: LO 6.7: Describe two mechanisms of ATP synthesis in the chloroplast.

Section Reference: Section 6.7: Photophosphorylation

60) Why does an electrochemical potential build up in mitochondria, but not in chloroplasts? a) Proton movement into the thylakoid lumen is neutralized by the movement of other ions. b) Proton movement into the intercristal space is neutralized by the movement of other ions. c) Proton movement into the cristae lumen is neutralized by the movement of other ions. d) The protons in chloroplasts are immediately joined to electrons. e) The protons in mitochondria are immediately joined to electrons.

Answer: a Difficulty: Hard Learning Objective: LO 6.7: Describe two mechanisms of ATP synthesis in the chloroplast.

Section Reference: Section 6.7: Photophosphorylation

61) When cyclic photophosphorylation is inhibited, which result would be expected? a) accelerated NADH production b) impaired development of higher plants c) increased ATP production d) improved growth of algae and simple plants Answer: b Difficulty: Medium Learning Objective: LO 6.7: Describe two mechanisms of ATP synthesis in the chloroplast.

Section Reference: Section 6.7: Photophosphorylation

62) Noncyclic photophosphorylation is characterized by: a) involvement of PSII, not PSI b) a requirement for CO2 c) a requirement for oxidized NADP

d) a requirement for sunlight Answer: d Difficulty: Medium Learning Objective: LO 6.7: Describe two mechanisms of ATP synthesis in the chloroplast.

Section Reference: Section 6.7: Photophosphorylation

63) When ATP is formed during oxygenic photosynthesis, the process is known as ________________. a) cyclic photophosphorylation b) noncyclic photophosphorylation c) dark reactions d) proton-motive photophosphorylation Answer: b Difficulty: Easy Learning Objective: LO 6.7: Describe two mechanisms of ATP synthesis in the chloroplast.

Section Reference: Section 6.7: Photophosphorylation

64) Algal cultures in sealed containers were exposed to radiolabeled [14C] CO2 for a brief incubation period of just a few seconds. Soluble molecules were extracted from the algae and subjected to 2D-paper chromatography. How many carbons are found in molecules from the most predominant spot on the chromatogram? a) 2 b) 1 c) 3 d) 4 e) 6 Answer: c Difficulty: Hard Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

65) Calvin originally thought that the acceptor molecule for carbon dioxide during carbon fixation contained how many carbons? a) 2 b) 1 c) 3 d) 4 e) 6 Answer: a Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

66) The initial product of carbon fixation contains ____ carbons, but it breaks down into two compounds containing _____ carbons. a) 8, 4 b) 6, 3 c) 6, 6 d) 10, 5 e) 12, 6 Answer: b Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

67) Starch stored as granules in the chloroplasts serves what purpose? a) It causes plant cells to swell. b) It provides plants with sugars at night when light-dependent reactions are not possible. c) It provides plants with cellulose during the day. d) It supplies plants with ribulose bisphosphate. e) It causes plant cells to shrink.

Answer: b

Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

68) Why is the conversion of CO2 to a 6-carbon sugar so energetically expensive? a) CO2 is the most highly reduced and least energetic form in which carbon can occur. b) CO2 is very unstable. c) CO2 is the most highly oxidized and least energetic form in which carbon can occur. d) CO2 is the most highly oxidized and most energetic form in which carbon can occur. e) CO2 is highly unstable and only moderately energetic which makes the process more expensive energetically.

Answer: c Difficulty: Hard Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

69) A mechanism that regulates basic cell processes, like protein folding, transcription, translation, and chloroplast metabolism, by controlling the activity of proteins is called ________. a) transubstantiation b) internal combustion c) redox control d) oxidation inhibition e) reduction counter-regulation Answer: c Difficulty: Easy Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

70) The reduction of ________ is accomplished with electrons passed through ferredoxin; this substance then reduces certain _______ in selected Calvin cycle enzymes.

a) thioredoxin, disulfide bridges b) thioredoxin, sulfhydryl groups c) sulfhydryl groups, thioredoxin d) disulfide bridges, thioredoxin e) thioredoxin, hydrogen bonds Answer: a Difficulty: Hard Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

71) Why are plants unlikely to produce many carbohydrates at night? a) Selected Calvin cycle enzymes are inactive in the dark because they are hydrogen-bound at night. b) Calvin cycle enzymes are denatured in the cold temperatures at night. c) Selected Calvin cycle enzymes are inactive in the dark because thioredoxin is oxidized and cannot reduce their disulfide linkages. d) Selected Calvin cycle enzymes are inactive in the dark because thioredoxin is reduced and can break their disulfide linkages.

Answer: c Difficulty: Hard Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

72) Mercaptoethanol is a reagent that breaks disulfide linkages. cycle enzymes with this reagent, what is the likely effect? a) It would competitively inhibit them. b) It would noncompetitively inhibit them. c) It would split them in two pieces. d) It would activate them. e) It would deactivate them.

Answer: d

If you were to treat Calvin

Difficulty: Hard Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

73) If Calvin cycle enzymes are treated with a reagent that stabilizes their disulfide linkages, what is the likely? a) It would competitively inhibit them. b) It would noncompetitively inhibit them. c) It would split them in two pieces. d) It would activate them. e) It would prevent them from catalyzing photosynthetic reactions.

Answer: e Difficulty: Hard Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

74) What substance reacts with RuBP by Rubisco to make 2-phosphoglycolate? a) ATP b) O2 c) CO2 d) NADPH e) glycolate Answer: b Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

75) 2-phosphoglycolate is converted into glycolate by an enzyme in the ________. a) peroxisome b) glyoxysome

c) stroma d) thylakoid disk e) thylakoid membrane Answer: c Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

76) To what organelle is glycolate passed after it is produced in the chloroplast? a) peroxisome b) glyoxysome c) lysosome d) Golgi apparatus e) rough endoplasmic reticulum Answer: a Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

77) Why is the process whereby O2 is added to RuBP called photorespiration? a) because O2 is released and CO2 is taken up b) because CO2 is released and O2 is taken up c) because breathing is necessary d) because RuBP is released e) because it occurs in crop plants Answer: b Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

78) Why does Rubisco show relatively little preference for CO2 as a substrate over O2? a) Rubisco’s active site can bind to CO2 and O2 equally well. b) CO2 and O2 bind to RuBP which has roughly equal affinity for CO2 and O2. c) Ancient atmospheric conditions had high amounts of O2 which selected for Rubisco to bind to either molecule. d) CO2 and O2 bind to a regulatory site on Rubisco instead of the active site.

Answer: b Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

79) Why might Rubisco have evolved with an inability to distinguish between CO2 and O2? a) low atmospheric O2 levels when Rubisco evolved b) low atmospheric CO2 levels when Rubisco evolved c) high atmospheric O2 levels when Rubisco evolved d) multiple subunits in the Rubisco enzyme competing for substrate e) selective advantages for plants that are able to bind both CO2 and O2 Answer: a Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

80) What determines the direction of the Rubisco-catalyzed reactions? a) the concentration of O2 alone b) the concentration of CO2 alone c) the CO2/O2 ratio available to the enzyme d) cofactors for Rubisco Answer: c Difficulty: Medium

Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

81) How do C4 and CAM plants overcome the negative effects of photorespiration? a) They destroy O2. b) They chemically alter O2 before it gets to the enzyme. c) They employ mechanisms that increase the CO2/O2 ratio to which Rubisco molecules are exposed. d) They chemically alter CO2. e) They destroy CO2.

Answer: c Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

82) What enzyme is the first enzyme in the C4 pathway that carries CO2 into the bundle sheath cells? a) Rubisco b) phosphenolpyruvate carboxylase c) pyruvate carboxylase d) phosphoenolpyruvate decarboxylase e) ATP synthase Answer: b Difficulty: Easy Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

83) The rate of photosynthetic CO2 fixation _____ and the rate of the release of CO2 by photorespiration _______ when _____ a plant is placed in a closed container. a) decreases, increases, C3

b) increases, decreases, C3 c) decreases, increases, C4 d) decreases, decreases, C3 e) increases, increases, C3 Answer: a Difficulty: Hard Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

84) What is the reason that C3 plants must open their stomata even when the climate is hot and dry? a) to take in CO b) to take in CO2 c) to take in water d) to let CO2 out of the leaf e) to take in O2 Answer: b Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

85) What anatomical specialization is typical of C4 plants? a) Mesophyll cells in C4 plants are scattered throughout the interior of the leaf. b) Bundle sheath cells in C4 plants are scattered throughout the interior of the leaf. c) C4 plants have two concentric cylinders of cells around their vascular tissue. d) Leaves of C4 plants are coated with extra waxy material. e) Rubisco floats free in the air spaces in the leaves of C4 plants.

Answer: c Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

86) How do the products of carbon fixation in a C4 plant move from the mesophyll to the bundle sheath cells? a) in lysosomes b) through plasmodesmata c) diffusion across the plasma membrane d) by ciliar movement e) in mitochondria Answer: b Difficulty: Easy Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

87) Why is CO2 split off of the C4 carriers once they get into the bundle sheath cells? a) so that the CO2 can be used by Rubisco to initiate the Calvin cycle b) so that the CO2 can be used by PEP carboxylase to initiate the Calvin cycle c) so that the CO2 can be used by Rubisco to initiate the C4 pathway d) so that the CO2 can be used by PEP carboxylase to initiate the C4 pathway e) so that the O2 can be used by Rubisco to initiate the Calvin cycle Answer: a Difficulty: Hard Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

88) What enzyme is responsible for fixing CO2 out of the atmosphere in C4 plants? a) PEP decarboxylase b) ATP synthase c) PEP carboxylase d) Rubisco e) ribulose bisphosphate carboxylase

Answer: c Difficulty: Easy Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

89) How do C4 plants manage to cause CO2 fixation to be favored over photorespiration? a) They can generate high [CO2]/[O2] ratios in the local Rubisco environment. b) They can generate low [CO2]/[O2] ratios in the local Rubisco environment. c) They destroy the cell wall. d) They convert CO2 to O2. e) They can generate high [CO2]/[O2] ratios in the local PEP carboxylase environment.

Answer: a Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

90) How does CO2 fixation differ in C3 and C4 plants? a) C3 plants fix CO2 and conduct the light-dependent reactions in the same cells; C4 plants conduct these activities in different cells. b) C4 plants fix CO2 and conduct the light-dependent reactions in the same cells; C3 plants conduct these activities in different cells. c) C3 plants fix CO2 and conduct the light-dependent reactions at the same time of day; C4 plants conduct these activities at different times of the day. d) C4 plants fix CO2 and conduct the light-dependent reactions at the same time of day; C3 plants conduct these activities at different times of the day.

Answer: a Difficulty: Hard Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

91) What substance is made in the mesophyll cells of CAM plants during the nighttime fixation of CO2 and then stored in the cell's central vacuole? a) malate b) oxygen c) RuBP d) PEP e) water Answer: a Difficulty: Easy Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

92) Into which structure is malate transported during nighttime carbon fixation? a) the plasma membrane b) the mitochondrion c) the central vacuole d) the lysosome e) the endoplasmic reticulum Answer: c Difficulty: Easy Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

93) Which three organelles in a leaf cell are found closely associated with each other and cooperate with each other in such a way that products of one organelle serve as substrates in another? a) peroxisomes, lysosomes, mitochondria b) chloroplasts, mitochondria, lysosomes c) chloroplasts, nuclei, mitochondria d) mitochondria, chloroplasts, peroxisomes e) chloroplasts, nuclei, peroxisomes

Answer: d Difficulty: Hard Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

94) Which of the following is NOT considered to be a contributor to increased global surface temperatures? a) greenhouse gas emission b) burning of fossil fuels c) deforestation d) carbon sequestration e) industrial and transportation infrastructure Answer: d Difficulty: Medium Learning Objective: LO 6.8: Compare the Calvin cycles of C3 plants, C4 plants, and CAM plants.

Section Reference: Section 6.8: Carbon Dioxide Fixation and the Synthesis of Carbohydrate

95) What molecular property of protoporphyrin IX permits light absorption in the blue and red wavelength ranges? a) two carboxylic acid residues b) multiple methyl groups c) conjugated single and double bonds d) four nitrogen atoms Answer: c Difficulty: Medium Learning Objective: LO 6.9: Explain the use of Photodynamic Therapy Section Reference: Section 6.9: Engineering Linkage: Photodynamic Therapy

96) The damage done to diseased or damaged tissues by the photosensitizing agent aminolevulinic acid (ALA) is a result of:

a) ALA producing oxygen radicals in tissues b) protoporphyrin IX converting into ALA which produces oxygen radicals in tissues c) ALA converting into protoporphyrin IX which produces oxygen radicals in tissues d) ALA producing high energy electrons which damage tissues at a distance Answer: c Difficulty: Medium Learning Objective: LO 6.9: Explain the use of Photodynamic Therapy Section Reference: Section 6.9: Engineering Linkage: Photodynamic Therapy

97) Which statement about photodynamic therapy (PDT) is INCORRECT? a) PDT treatments can use different light wavelengths b) treatments with different light wavelengths will all be of the same duration c) patients will endure pain during PDT d) red light wavelengths are more effective in deep tumor treatments Answer: b Difficulty: Easy Learning Objective: LO 6.9: Explain the use of Photodynamic Therapy Section Reference: Section 6.9: Engineering Linkage: Photodynamic Therapy

Question Type: Multiple Select

98) An unexpected characteristic of chloroplasts is their ability to differentiate into _____________. (Select all that apply) a) chromoplasts b) mitochondria c) amyloplasts d) vacuoles e) gerontoplasts Answer: a, e Difficulty: Hard Learning Objective: LO 6.5: Identify the functions of chromoplasts.

Section Reference: Section 6.5: Green Cells: Chromoplasts

Question Type: Multiple Select

99) Contributions to the proton gradient created through photosynthetic light reactions include: (Select all correct choices) a) protons generated through splitting water molecules b) reduction of plastoquinol by cytochrome b6f c) reduction of PQ d) oxidation of NADPH Answer: a, c Difficulty: Hard Learning Objective: LO 6.6: Compare the events of photosystem II and photosystem I. Section Reference: Section 6.6: Photosynthetic Units and Reaction Centers

Question Type: Multiple Select

100) A major advantage in photodynamic therapy is that ________________: (Select all correct choices) a) the photosensitizing agent is selectively taken up by bone tissue b) damaged tissues will preferentially absorb the photosensitizing agent c) diseased tissues will preferentially absorb the photosensitizing agent d) cancer cells will preferentially absorb the photosensitizing agent Answer: b, c, d Difficulty: Medium Learning Objective: LO 6.9: Explain the use of Photodynamic Therapy Section Reference: Section 6.9: Engineering Linkage: Photodynamic Therapy

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 7

Question Type: Multiple Choice

1) What could be defined as an organized network of extracellular materials found beyond the plasma membrane? a) intracellular matrix b) extracellular matrix c) extracellular nexus d) intercellular material e) epicellular matrix Answer: b Difficulty: Easy Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

2) You place mammary gland epithelial cells in culture and then treat them with enzymes that digest the surrounding extracellular matrix. What happens? a) The secretory and synthetic activities of the cells decrease. b) The secretory and synthetic activities of the cells increase. c) The cells die. d) The cells differentiate. e) The secretory and synthetic activities of the cells do not change.

Answer: a Difficulty: Medium Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

3) You place mammary gland epithelial cells in culture and then treat them with enzymes that digest the surrounding extracellular matrix. If extracellular matrix materials are then added back to the cells, what happens? a) The cells continue to decline in secretory and synthetic activities. b) The cells digest the extracellular materials through endocytosis. c) The differentiated state of the cells is restored and the cells produce their usual products. d) The cells die. e) The cells become stem cells and differentiate into many different types.

Answer: c Difficulty: Medium Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

4) The basement membrane of the__________ may thicken abnormally in long-term diabetics causing kidney failure. a) dermis b) epidermis c) glomerulus d) bladder epithelium e) pericardium Answer: c Difficulty: Easy Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

5) All collagen family members consist of _____ chains arranged in a _______ in at least part of their length. a) 2, double helix b) 3, double helix c) 3, triple helix d) 3, triple lattice e) 2, triple helix

Answer: c Difficulty: Medium Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

6) Collagen fibrils are strengthened by covalent cross-links between _________ and ________ residues on adjacent collagen molecules. a) lysine, hydroxylysine b) proline, hydroxyproline c) lysine, hydroxyproline d) proline, hydroxylysine e) proline, lysine Answer: a Difficulty: Medium Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

7) In the corneal stroma, the uniformity of collagen fiber size and the ordered packing of the fibers confers what property on the corneal stroma? a) strength b) flexibility c) extensibility d) transparency e) opacity Answer: d Difficulty: Easy Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

8) Basement membranes contain type IV collagen, a nonfibrillar collagen organized in a flattened network. The type IV collagen trimer has some interspersed nonhelical segments.

What property does this confer upon basement membranes? a) strength b) flexibility c) extensibility d) transparency e) opacity Answer: b Difficulty: Easy Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

9) Mutations in Type I collagen genes cause a potentially lethal condition characterized by extremely fragile bones, thin skin and weak tendons. This condition is called _______. a) osteogenesis imperfecta b) Ehler-Danlos syndrome c) Alport syndrome d) dwarfism and skeletal deformities e) diabetes Answer: a Difficulty: Easy Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

10) Type II collagen gene mutations alter the properties of cartilage tissue and are known to cause _______. a) osteogenesis imperfecta b) Ehler-Danlos syndromes c) Alport syndrome d) dwarfism and skeletal deformities e) diabetes

Answer: d Difficulty: Easy Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

11) Mutations in collagen genes can lead to a variety of distinct but related defects in collagen matrix structure, one of which causes hyperflexible joints and highly extensible skin. These defects are usually referred to as ______. a) osteogenesis imperfecta b) Ehler-Danlos syndromes c) Alport syndromes d) Cushing's syndrome e) diabetes Answer: b Difficulty: Easy Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

12) What substance joins proteoglycans together into gigantic complexes called proteoglycan aggregates? a) hyaluronidase b) hyaluronic acid c) proteoglycase d) fibronectin e) laminin Answer: b Difficulty: Easy Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

13) Which of the following is NOT a role of proteoglycan? a) attracting large numbers of cations b) attracting large numbers of anions c) maintaining a hydrated extracellular matrix d) growth factor binding Answer: b Difficulty: Medium Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

14) If antibodies that neutralize fibronectin are incubated with an embryo through which neural crest cells are migrating, what happens? a) Neural crest cell movements are inhibited. b) Neural crest cell movements are excited. c) Neural crest cells die. d) Neural crest cells divide. e) Neural crest cells convert into muscle cells.

Answer: a Difficulty: Medium Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

15) What would be the effect on primordial germ cells when an embryo is exposed to laminin-specific neutralizing antibodies? a) They arrive at the developing gonad more quickly. b) Their movement to the developing gonad is disrupted. c) They begin to divide rapidly. d) They increase greatly in size. e) Their nuclei disintegrate.

Answer: b Difficulty: Medium

Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

16) The degradation of the extracellular matrix, along with cell surface proteins, is accomplished mostly by a _____-containing enzyme family called MMPs. a) coppers b) iron c) zinc d) magnesium e) manganese Answer: c Difficulty: Easy Learning Objective: LO 7.1: Identify the structures and functions of the extracellular matrix in animal tissue.

Section Reference: Section 7.1: Extracellular Interactions

17) Three dimensional masses of organ tissues grown in vitro are called ___________. a) organs b) organoids c) organelles d) organic matrices Answer: b Difficulty: Easy Learning Objective: LO 7.2: Relate the potential applications of organoids in research and clinical settings.

Section Reference: Section 7.2: Engineering Linkage: Organoids

18) Organoid uses currently include all of the following EXCEPT: a) patient-individualized testing of efficacy of therapeutic drugs b) mass testing of efficacy of therapeutic drugs c) generation of organs for researching disease progression d) generation of organs to replace those found in the human body

Answer: d Difficulty: Medium Learning Objective: LO 7.2: Relate the potential applications of organoids in research and clinical settings.

Section Reference: Section 7.2: Engineering Linkage: Organoids

19) Organoid tissues are derived by growing cells from all of the following EXCEPT: a) tissue specific stem cells b) induced pluripotent stem cells c) embryonic stem cells d) certain tumor cells Answer: d Difficulty: Medium Learning Objective: LO 7.2: Relate the potential applications of organoids in research and clinical settings.

Section Reference: Section 7.2: Engineering Linkage: Organoids

20) What integral membrane protein family made of two membrane-spanning chains (a and b) is involved in attaching cells to their extracellular microenvironment? a) laminins b) fibronectins c) integrins d) myosins e) lysins Answer: c Difficulty: Easy Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

21) In an integrin, what structure is it that crosses the lipid bilayer?

a) a transmembrane pleated sheet b) a transmembrane spear c) a transmembrane plate d) a transmembrane helix e) a bent, curved leg Answer: d Difficulty: Easy Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

22) The activation of a membrane integrin by the binding of its cytoplasmic portion to molecules in the cytoplasm and the resultant increase in its affinity for an extracellular ligand is called ________. a) inside-out signaling b) outside-in signaling c) right-side-out signaling d) simple signaling e) integrination Answer: a Difficulty: Easy Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

23) Evidence strongly suggests that the bent conformation of an integrin is _______ and unable to bind its ligand. a) loose b) active c) tight d) stretched e) inactive Answer: e Difficulty: Easy

Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

24) You are investigating the interactions of integrin a and b subunits and isolate the extracellular portion of an integrin as a soluble a/b heterodimer. The heterodimer lacks the associated transmembrane and cytoplasmic domains normally present as part of the molecule.

You experimentally link the a and b subunits at the bases of their legs so that the ligand-binding regions of the a and b subunits approach one another and the legs are in the bent conformation.

Which of the following statements is the best prediction of what will happen? a) The molecules will bind their ligand tightly. b) The molecules will be unable to bind a ligand. c) The molecules will be cleaved. d) The molecules will denature their ligand. e) The molecules will denature and degrade.

Answer: b Difficulty: Hard Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

25) If experimentally linked a/b heterodimer integrin subunits are separated, what happens? a) The molecules bind their ligand tightly b) The molecules are unable to bind a ligand. c) The molecules are cleaved. d) The molecules denature their ligand. e) The molecules are denatured and degraded.

Answer: a Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

26) What ion is NOT known to bind to integrins?

a) calcium b) magnesium c) sodium d) divalent cations e) manganese Answer: c Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

27) What kind of experiments have provided evidence that most integrins have unique functions? a) enzyme assays b) gene addition experiments c) gene knockout experiments in mice d) freeze-fracture, freeze etch experiments e) sucrose density centrifugation Answer: c Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

28) You coat a Petri dish with fibronectin and proteoglycans and then culture cells on the dish.

The cells adhere to the dish. You repeat the experiment but this time add RGD tripeptides to the culture dish as the cells are added. What happens? a) The cells adhere as they normally do. b) The cells die immediately. c) The cells lyse immediately. d) The cells do not adhere to the dish. e) The cells immediately change their phenotype.

Answer: d Difficulty: Medium

Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

29) You coat a Petri dish with fibronectin and proteoglycans and then culture cells on the dish.

The cells adhere to the dish. You repeat the experiment but this time add RGD tripeptides to the culture dish as the cells are added. The result of this experiment is an example of what biochemical process? a) competitive inhibition b) noncompetitive inhibition c) enzymatic activation d) feedback inhibition e) allosterism Answer: a Difficulty: Hard Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

30) Why do cells flatten out as they make contact with a surface? a) They lose water. b) They extrude cytoplasm. c) They send out projections that make increasingly stable attachments. d) Their membranes stiffen. e) They make focal assignations.

Answer: c Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

31) In focal adhesion, large clusters of integrins bond to which component via various adaptors? a) tubulins of the cytoskeleton

b) myosin of the cytoskeleton c) actin of the cytoskeleton d) dynein of the cytoskeleton e) band III protein of the membrane Answer: c Difficulty: Easy Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

32) The tightest attachment between a cell and its extracellular matrix is seen at the site where an epithelial cell is attached to the underlying basement membrane. The specialized adhesive structure found at such a site is called a(n) ________. a) tight junction b) spot desmosome c) plasmodesma d) hemidesmosome e) gap junction Answer: d Difficulty: Easy Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

33) Filaments connected to the dense plaque underlying the membrane in a hemidesmosome course outward into the cytoplasm. These filaments are composed of the protein _____ and are best known as ______. a) actin, microfilaments b) keratin, microfilaments c) actin, intermediate filaments d) keratin, intermediate filaments e) tubulin, intermediate filaments Answer: d Difficulty: Easy

Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

34) Epidermolysis bullosa, an inherited blistering disease, is caused by ________. a) production of antibodies against hemidesmosome plaque proteins b) production of autoantibodies c) production of antibodies against spot desmosome plaque proteins d) genetic alterations in any one of a number of hemidesmosomal proteins e) production of antibodies against connexins Answer: d Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

35) Focal adhesions ________. a) may act as a type of sensory structure b) collect information about the physical properties of the extracellular environment c) collect information about the chemical properties of the extracellular environment d) transmit information to the cell interior that may lead to changes in cell adhesion, proliferation or survival e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

36) Focal adhesions ________. a) have been implicated in cell locomotion b) contain integrins that develop transient interactions with the extracellular matrix c) collect information about the chemical properties of the extracellular environment

d) transmit information to the cell interior that may lead to changes in cell adhesion, proliferation or survival e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

37) Cells were allowed to bind to beads that had been covered with a coating of fibronectin.

When the membrane-bound beads were pulled by an optical tweezer, the resultant mechanical stimulus was transmitted into the cell interior. What response did this cause? a) It generated a wave of Src kinase activity. b) It caused nuclear shrinkage. c) It caused activation of phosphofructokinase. d) It caused inhibition of phosphofructokinase. e) It inhibited Src kinase activity.

Answer: a Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

38) In which disease does an individual produce antibodies against proteins present in hemidesmosmes? a) epidermolysis bullosa b) bullous pemphigoid c) hemidesmosomosis d) eczema Answer: b Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

39) Which disease is an inherited blistering disease that can occur in patients with genetic alterations in any one of a number of hemidesmosomal proteins, including the a6 or b4 integrin subunit, collagen VII or laminin-5? a) epidermolysis bullosa b) bullous pemphigoid c) blisterosis d) hemidesmosomosis e) eczema Answer: a Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

40) What proteins have been shown to be altered by genetic mutations in patients who suffer from epidermolysis bullosa? a) the a6 integrin subunit b) the b4 integrin subunit c) collagen VII d) laminin-5 e) all of these are possibilities Answer: e Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

41) You disaggregate cells from two different developing organs and mix them together.

Initially, they form a mixed clump. What happens next? a) The clump stabilizes. b) The cells sort themselves out so that each cell adheres only to cells of the same type. c) The mixed clump persists.

d) The clumped cells die. e) The clump forms a mesenchyme.

Answer: b Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

42) ________ are members of an integral membrane glycoprotein family that bind to specific sugar arrangements in oligosaccharides that project from the surfaces of other cells. a) Selectins b) Integrins c) Immunoglobulin super family proteins d) Cadherins e) Calmodulins Answer: a Difficulty: Easy Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

43) Lymphocytes isolated from the endothelial lining of lymph nodes are labeled with radioactive isotopes. They are then exposed to frozen tissue sections of a lymphoid organ. What happens? a) The lymphocytes bind uniformly to the sections. b) The lymphocytes bind to each other. c) The lymphocytes selectively adhere to the endothelial lining. d) The lymphocytes selectively adhere to antibodies for selectins. e) The lymphocytes do not stick to the sections.

Answer: c Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

44) Lymphocyte homing can be blocked in what way? a) Treatment with antibodies against specific lymphocyte surface glycoproteins b) Treatment with antibodies against specific IgSFs c) Treatment with antibodies against specific integrins d) Treatment with antibodies against specific ECM glycoproteins e) Treatment with antibodies against specific cadherins Answer: a Difficulty: Hard Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

45) While most IgSF members are involved in various aspects of immune function, some of them mediate ____________ cell-cell adhesion. a) calcium-dependent b) calcium-independent c) magnesium-dependent d) manganese-dependent e) iron-independent Answer: b Difficulty: Easy Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

46) The bonds that selectins form with their ligands become _______ when the interaction is __________. a) stronger, placed under mechanical stress b) weaker, placed under mechanical stress c) stronger, exposed to a higher temperature d) more elastic, exposed to a higher temperature e) more elastic, placed under mechanical stress

Answer: a Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

47) What is thought to be the origin of immunoglobulins? a) immune system molecules in invertebrates b) cell-adhesion receptors in invertebrates c) cell-adhesion receptors in fish d) cell-adhesion molecules in amphibians e) immune system molecules in reptiles Answer: b Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

48) What is the function of most IgSFs? a) cell adhesion b) cell division c) mediating specific interactions of epithelial cells with cells needed for immune response d) mediating specific interactions of lymphocytes with cells needed for the immune response e) cell fusion Answer: d Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

49) L1 is an IgSF molecule that has been shown to be important in neural development; it is thought that it may be involved in axon growth within the embryonic nervous system. What evidence supports this statement? a) L1 mutants always die. b) L1 mutants show deficits in their vision. c) People who die of L1-deficiency are often missing two large nerve tracts connecting brain/spinal cord regions. d) People who die of L1-deficiency are often missing a significant portion of their brain. e) People who die of L1-deficiency are often missing a significant portion of their spinal cord.

Answer: c Difficulty: Easy Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

50) You genetically engineer nonadhesive cells to express different varieties of cadherins and then mix the cells in various combinations. What is the best prediction of the outcome? a) The genetically engineered cells adhere preferentially to cells expressing one of the other cadherins. b) The genetically engineered cells adhere preferentially to cells expressing the same cadherins. c) The genetically engineered cells do not stick to any other cells. d) The genetically engineered cells die. e) The genetically engineered cells migrate to a different location.

Answer: b Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

51) Cadherins appear to be important in holding cells together in __________ tissues. a) mesenchymal b) loosely cohesive c) tightly cohesive d) noncohesive e) gel-like

Answer: c Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

52) Calcium ions form bridges between ________. a) successive domains of a given cadherin molecule b) cadherins on adjacent cells c) cadherins on the same cell d) cadherins and IgSFs e) IgSFs and selectins Answer: a Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

53) What determines the strength of adhesion between

cells held together by cadherins?

a) the length of the cadherins connecting the cells b) the width of the cadherins connecting the cells c) the amount of tryptophan in the cadherins connecting the cells d) the number of cadherins in a cluster connecting the cells e) the number of tyrosine residues in the cadherins connecting the cells Answer: d Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

54) The loss of cadherin function may be instrumental in what disease state?

a) colds b) the spread of benign tumors c) the spread of malignant tumors d) influenza e) AIDS Answer: c Difficulty: Easy Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

55) From the apical surface to the basal surface of an epithelial cell, what is the order of cell junctions observed in the junctional complex? a) tight junction, belt desmosome, spot desmosomes, gap junctions b) tight junction, adherens junction, gap junction, spot desmosomes c) belt desmosome, tight junction, gap junctions, spot desmosomes d) belt desmosome, gap junctions, tight junctions, spot desmosomes e) gap junctions, spot desmosomes, belt desmosome, tight junction Answer: b Difficulty: Hard Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

56) What type of cell adhesion molecule is associated with formation of adherens junctions? a) adherins b) selectins c) IgSFs d) integrins e) cadherins Answer: e Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

57) What can be described as a tightly adherent, polarized cell layer? a) a mesenchyme b) cartilage c) an epithelium d) a mesothelium e) mesoderm Answer: c Difficulty: Easy Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

58) What can be described as solitary, nonadhesive, nonpolarized migratory cells arrangement? a) a mesenchyme b) cartilage c) an epithelium d) a mesothelium e) an endothelium Answer: a Difficulty: Easy Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

59) Which of the following tissues is typically NOT derived from mesenchymal cells? a) mesodermal tissues b) ectodermal tissues c) blood d) muscle e) bone

Answer: b Difficulty: Easy Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

60) The cells of the epiblast of a developing mammalian embryo display cell adhesion molecules on their surfaces that presumably promote their close association with one another. What are these molecules termed? a) selectins b) E-cadherins c) P-cadherins d) integrins e) IgSFs Answer: b Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

61) What is thought to promote the release of future mesoderm cells from an epithelium and their transformation into mesenchymal cells? a) a reduction in the expression of E-cadherin genes b) an increase in the expression of E-cadherin genes c) degradation of the cell membrane d) the cytoplasm taking on an anti-adhesive character e) autophagy of the nucleus Answer: a Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

62) Which tissues below are typically derived from the single-celled epithelium on the dorsal surface of a chick embryo after gastrulation? a) muscle b) skin, ectodermal tissues and the nervous system c) only skin d) only ectodermal tissues e) only tissues of the nervous system Answer: b Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

63) Which tissues below are typically derived from the epithelium on the dorsal surface of a mammalian embryo once some of these cells begin expressing N-cadherins and stop expressing E-cadherins? a) skin b) only brain c) only spinal cord d) only neural tube e) brain, spinal cord and neural tube Answer: e Difficulty: Hard Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

64) Which tissues below are NOT typically derived from the cells on the dorsal surface of a mammalian embryo after gastrulation once some of these cells begin expressing N-cadherins and stop expressing E-cadherins? a) skin b) brain c) spinal cord d) neural tube

Answer: a Difficulty: Hard Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

65) Desmosomes are particularly numerous in tissues _____________. a) that are subjected to mechanical stress b) like cardiac muscle c) like the epithelial layers of the skin d) like the epithelial layers of the uterine cervix e) all of these are correct Answer: e Difficulty: Easy Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

66) The cadherins of the desmosomes ____________. a) have a different domain structure from classical cadherins b) are referred to as desmogleins c) are called desmocollins d) all choices are correct Answer: d Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

67) The human disease pemphigus vulgaris __________. a) is characterized by a loss of epidermal cell-cell adhesion b) is an autoimmune disease

c) is characterized by severe blistering of the skin d) is caused by the production of antibodies against one of the desmogleins e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

68) Attachment of an integrin to its ligand can induce which of the following responses within a cell? a) changes in cytoplasmic pH b) changes in cytoplasmic C2+ ion concentration c) protein phosphorylation d) gene expression e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

69) What forms the barrier of the tight junctions that seals off the space between adjacent cells? a) paired rows of aligned integral membrane proteins b) paired rows of aligned phospholipids c) paired rows of carbohydrates d) paired rows of polynucleotides e) interdigitating integral membrane proteins Answer: a Difficulty: Easy Learning Objective: LO 7.5 Explain how the structure of a tight junction contributes to its function.

Section Reference: Section 7.5 Tight Junctions: Sealing The Extracellular Space

70) Which tight junction will form a tighter seal? a) one with a single strand of aligned integral membrane proteins b) one with a number of parallel, interconnected strands of aligned integral membrane proteins c) tight junctions containing a special kind of phospholipid d) tight junctions containing a special kind of carbohydrate e) one with a number of parallel, interconnected strands of interdigitated integral membrane proteins Answer: b Difficulty: Medium Learning Objective: LO 7.5 Explain how the structure of a tight junction contributes to its function.

Section Reference: Section 7.5 Tight Junctions: Sealing The Extracellular Space

71) One small region of a human kidney tubule known as the thick ascending limb (or TAL) has tight junctions that are permeable to magnesium (Mg2+) ions. What is thought to account for the permeability of this tight junction to magnesium ions? a) The membrane in this region is leaky because of special phospholipids. b) Loops of claudin molecules that extend into the extracellular space form pores in the TAL. c) Loops of claudin molecules that extend into the cytoplasm form pores in the TAL. d) Loops of claudin molecules fully embedded in the TAL membrane form pores in the TAL. e) Claudin molecules form gap junctions that allow the passage of magnesium ions.

Answer: b Difficulty: Medium Learning Objective: LO 7.5 Explain how the structure of a tight junction contributes to its function.

Section Reference: Section 7.5 Tight Junctions: Sealing The Extracellular Space

72) Animals lacking the claudin-1 gene suffered from ___________. a) uncontrolled water loss b) high salt loading c) low salt loading d) Mg2+ ion permeability e) constant, unremitting pain

Answer: a Difficulty: Medium Learning Objective: LO 7.5 Explain how the structure of a tight junction contributes to its function.

Section Reference: Section 7.5 Tight Junctions: Sealing The Extracellular Space

73) Patients with abnormal claudin-16 gene suffered from ___________. a) uncontrolled water loss b) high salt loading c) low salt loading d) excessive Mg2+ ion permeability e) constant, unremitting pain Answer: d Difficulty: Medium Learning Objective: LO 7.5 Explain how the structure of a tight junction contributes to its function.

Section Reference: Section 7.5 Tight Junctions: Sealing The Extracellular Space

74) The blood-brain barrier is very restrictive, preventing even water and small ions from crossing. However, _______ can pass through the blood-brain barrier by sending a signal that opens up the junction. a) red blood cells b) immune system cells c) platelets d) complement cells e) epithelial cells Answer: b Difficulty: Medium Learning Objective: LO 7.5 Explain how the structure of a tight junction contributes to its function.

Section Reference: Section 7.5 Tight Junctions: Sealing The Extracellular Space

75) The opening in the center of a connexon that allows the passage of solutes between cells is called a(n) ________. a) connexin b) annulus c) cumulous d) lunulus e) limulus Answer: b Difficulty: Easy Learning Objective: LO 7.6: Distinguish the mechanisms of short-range, mid-range, and long-range intercellular communication.

Section Reference: Section 7.6: Intercellular Communication

76) Each connexon in a gap junction is constructed of ___ connexin subunits. a) 2 b) 4 c) 6 d) 8 e) 10 Answer: c Difficulty: Easy Learning Objective: LO 7.6: Distinguish the mechanisms of short-range, mid-range, and long-range intercellular communication.

Section Reference: Section 7.6: Intercellular Communication

77) During gap junction formation, connexons in apposing cells become tightly connected through extensive noncovalent interactions of __________. a) connexin subunit intracellular domains b) connexin subunit extracellular domains c) connexin carbohydrates d) connexin lipids e) polynucleotides Answer: b

Difficulty: Hard Learning Objective: LO 7.6: Distinguish the mechanisms of short-range, mid-range, and long-range intercellular communication.

Section Reference: Section 7.6: Intercellular Communication

78) What kind of molecule does NOT pass through a gap junction? a) ions b) cAMP c) inositol phosphates d) ribosomal RNA e) cGMP Answer: d Difficulty: Medium Learning Objective: LO 7.6: Distinguish the mechanisms of short-range, mid-range, and long-range intercellular communication.

Section Reference: Section 7.6: Intercellular Communication

79) A new type of communication system has been discovered that consists of thin, highly elongated tubules capable of conducting cell-surface proteins, cytoplasmic vesicles and calcium signals from one cell to another. This system is referred to as ________. a) T tubules b) scanning tunneling EMs c) tunneling nanotypes d) tunneling nanotubes e) sarcoplasmic tubules Answer: d Difficulty: Easy Learning Objective: LO 7.6: Distinguish the mechanisms of short-range, mid-range, and long-range intercellular communication.

Section Reference: Section 7.6: Intercellular Communication

80) Which animal cell structure do plasmodesmata in plants most closely resemble? a) maculae adherens

b) spot desmosomes c) zonulae adherens d) gap junctions e) zonulae occludens Answer: d Difficulty: Medium Learning Objective: LO 7.6: Distinguish the mechanisms of short-range, mid-range, and long-range intercellular communication.

Section Reference: Section 7.6: Intercellular Communication

81) What structure accounts for the fact that plants lack the specialized junctions seen in animal cells? a) the presence of the large central vacuole b) the presence of chloroplasts c) the presence of the cell wall d) the presence of mitochondria e) the absence of centrioles, basal bodies, cilia and flagellae Answer: c Difficulty: Medium Learning Objective: LO 7.6: Distinguish the mechanisms of short-range, mid-range, and long-range intercellular communication.

Section Reference: Section 7.6: Intercellular Communication

82) What lines the plasmodesmata seen in plant cells? a) integral membrane proteins b) peripheral proteins c) carbohydrates d) plasma membrane e) DNA Answer: d Difficulty: Medium Learning Objective: LO 7.6: Distinguish the mechanisms of short-range, mid-range, and long-range intercellular communication.

Section Reference: Section 7.6: Intercellular Communication

83) The dense central structure that is derived from the smooth endoplasmic reticulum and usually seen in the plasmodesmata is called a(n) ________. a) desmosome b) desmotubule c) hemidesmosome d) annulus e) desmoglein Answer: b Difficulty: Easy Learning Objective: LO 7.6: Distinguish the mechanisms of short-range, mid-range, and long-range intercellular communication.

Section Reference: Section 7.6: Intercellular Communication

84) From what cell organelle does the desmotubule appear to be derived? a) Smooth endoplasmic reticulum of the two cells b) Rough endoplasmic reticulum of the two cells c) Golgi apparatus of the two cells d) secretory vesicles of the two cells e) cell wall of both cells Answer: a Difficulty: Easy Learning Objective: LO 7.6: Distinguish the mechanisms of short-range, mid-range, and long-range intercellular communication.

Section Reference: Section 7.6: Intercellular Communication

85) You are studying a plant and inject fluorescein, a fluorescent dye, into a single cell on the surface of the plant. After a brief period of time, the dye spreads to cells neighboring the injected cell. What do you conclude? a) The cells are connected by the cell wall. b) The cells are connected by tight junctions. c) The cells are connected by gap junctions. d) The cells are connected by plasmodesmata.

e) The cells are connected by zonulae adherens.

Answer: d Difficulty: Medium Learning Objective: LO 7.6: Distinguish the mechanisms of short-range, mid-range, and long-range intercellular communication.

Section Reference: Section 7.6: Intercellular Communication

86) Which of the following is NOT a function of the plant cell wall? a) It allows plant cells to develop osmotic turgor pressure that pushes against their surrounding walls. b) It provides mechanical support for individual cells and serves as a type of "skeleton" for the whole plant. c) It protects cells against damage from mechanical abrasion, osmotic influx of water & pathogens. d) It prevents cell-cell interactions. e) It can be a source of signals that alter activities of cells that it contacts.

Answer: d Difficulty: Medium Learning Objective: LO 7.7: Describe the function of each component that makes up the plant cell wall.

Section Reference: Section 7.7: Cell Walls

87) The enzyme embedded in the plant cell membrane that catalyzes the growth of a cellulose molecule is called _________. a) cellulase b) cellulose synthase c) Rubisco d) PEP carboxylase e) cellulose transferase Answer: b Difficulty: Easy Learning Objective: LO 7.7: Describe the function of each component that makes up the plant cell wall.

Section Reference: Section 7.7: Cell Walls

88) Which plant cell wall molecule is economically important as a component essential for the production of jams and jellies? a) hemicellulose b) pectin c) amylopectin d) proteins e) desmotubulin Answer: b Difficulty: Easy Learning Objective: LO 7.7: Describe the function of each component that makes up the plant cell wall.

Section Reference: Section 7.7: Cell Walls

89) What class of plant cell proteins facilitates plant cell growth by causing a localized relaxation of the cell wall, which allows the cell to elongate at that site in response to turgor pressure generated within the cell? a) extensins b) desmins c) expansins d) protein kinases e) phosphatases Answer: c Difficulty: Easy Learning Objective: LO 7.7: Describe the function of each component that makes up the plant cell wall.

Section Reference: Section 7.7: Cell Walls

90) What type of protein also seen in animal cells spans the plant plasma membrane and is thought to transmit signals from the cell wall to the cytoplasm? a) protein kinase b) catalase c) acid phosphatase

d) succinate dehydrogenase e) adenylate cyclase Answer: a Difficulty: Medium Learning Objective: LO 7.7: Describe the function of each component that makes up the plant cell wall.

Section Reference: Section 7.7: Cell Walls

91) Cell walls of young, undifferentiated plant cells grow along with the cells of which they are a part and thus exhibit extensibility. What are they known as? a) primary walls b) secondary walls c) expandophiles d) complete walls e) incomplete walls Answer: a Difficulty: Easy Learning Objective: LO 7.7: Describe the function of each component that makes up the plant cell wall.

Section Reference: Section 7.7: Cell Walls

92) The thicker walls seen in mature plants that no longer allow extensive growth of the cell wall are known as _______. a) primary walls b) secondary walls c) complete walls d) incomplete walls Answer: b Difficulty: Easy Learning Objective: LO 7.7: Describe the function of each component that makes up the plant cell wall.

Section Reference: Section 7.7: Cell Walls

93) How is the structure of the mature plant cell wall similar to the structure of the corneal stroma of the chicken embryo? a) Both contain cellulose. b) Both contain adjacent layers of fibers that run parallel to each other. c) Both contain phospholipids. d) Both contain adjacent layers of fibers that are arranged perpendicular to each other. e) Both are composed of collagen.

Answer: d Difficulty: Hard Learning Objective: LO 7.7: Describe the function of each component that makes up the plant cell wall.

Section Reference: Section 7.7: Cell Walls

94) The green algae which first grew in a terrestrial environment are called ______________ a) cyanobacteria b) charophycean green algae c) filamentous green algae d) bryozoans Answer: b Difficulty: Easy Learning Objective: LO 7.8: Explain how some characteristics of cell walls may have facilitated the evolutionary transition from water to land.

Section Reference: Section 7.8: Green Cells: Cell Walls and Plant Terrestrialization

Question Type: Multiple Select

95) Which of the following proteins are known to be associated with focal adhesions? all correct choices) a) actin b) aconitase c) myosin d) malin

(Select

Answer: a, c Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

Question Type: Multiple Select

96) The filaments associated with hemidesmosomes are correctly known as __________.

(Select all correct choices) a) actin filaments b) keratin filaments c) microtubules d) intermediate filaments Answer: b, d Difficulty: Medium Learning Objective: LO 7.3: Describe how a cell-surface protein can be involved in both cell adhesion and transmembrane signal transduction.

Section Reference: Section 7.3: Interactions of Cells with Extracellular Materials

Question Type: Multiple Select

97) Patients that have died of L1-deficiency disease are missing a nerve tract that ________.

(Select all that apply) a) runs between the brain and the spinal cord b) runs between the two halves of the brain c) runs between the spinal cord and cerebellum d) runs between the brain and the endocrine system Answer: a,b Difficulty: Medium

Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

Question Type: Multiple Select

98) Which of the following is typified by an epithelial-mesenchymal transition or EMT? (Select all correct choices) a) formation of the mesoderm during gastrulation in a chick or mammalian embryo b) cells breaking away from a cohesive epiblast c) fusion of sperm and egg d) formation of cartilage Answer: a,b Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

Question Type: Multiple Select

99) Which of the following tissues are typically derived from mesenchymal cells? correct choices)

(Select all

a) mesodermal tissues b) ectodermal tissues c) blood d) muscle Answer: a, c, d Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

Question Type: Multiple Select

100) What changes in the central region of the dorsal surface of the single-celled epithelial layer of a chick embryo lead to the formation of the primitive nervous system? (Select all correct responses) a) a reduction in the expression of E-cadherin genes b) a reduction in the expression of N-cadherin genes c) an elevation in the expression of N-cadherin genes d) an elevation in the expression of E-cadherin genes Answer: a, c Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes.

Section Reference: Section 7.4 Interactions of Cells with other Cells

Question Type: Multiple Select

101) Cadherin clusters of adherens junctions _____________.

(Select all correct responses)

a) connect the external environment to the actin cytoskeleton b) do not require calcium ions to perform their function c) provide a pathway for signals to be transmitted from the cell exterior to the cytoplasm d) connect the external environment to the vimentin cytoskeleton Answer: a, c Difficulty: Medium Learning Objective: LO 7.4 Explain the functions of selectins, immunoglobulins, integrins, cadherins, adherens junctions, and desmosomes..

Section Reference: Section 7.4 Interactions of Cells with other Cells

Question Type: Multiple Select

102) What challenges faced plants as they adapted to terrestrial, rather than aquatic growth?

(Select all correct choices) a) reduced ability to photosynthesize due to less sunlight availability b) increased risk of cellular dehydration c) increased risk of mutation due to ultraviolet radiation d) increased risk of protein or lipid damage due to oxygen exposure Answer: b, c Difficulty: Hard Learning Objective: LO 7.8: Explain how some characteristics of cell walls may have facilitated the evolutionary transition from water to land.

Section Reference: Section 7.8: Green Cells: Cell Walls and Plant Terrestrialization

Question Type: Multiple Select

103) Which characteristics possessed by land plants are lacking in aquatic plants? (Select all correct choices) a) chloroplasts arranged in rosette formations b) rosette arrangements of chlorophyll synthase c) lower percentages of cellulose in the cell wall d) higher percentages of cellulose in the cell wall Answer: b, d Difficulty: Medium Learning Objective: LO 7.8: Explain how some characteristics of cell walls may have facilitated the evolutionary transition from water to land.

Section Reference: Section 7.8: Green Cells: Cell Walls and Plant Terrestrialization

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 8

Question Type: Multiple Choice

1) When electron micrographs were first taken of the cell interior, what kinds of structures were seen? a) membrane-bound vesicles of varying diameter, containing material of different electron density b) long channels bounded by membranes and radiating through the cytoplasm c) an interconnected network of canals d) stacks of flattened, membrane-bound sacs called cisternae e) all of these are correct Answer: e Difficulty: Easy Learning Objective: LO 8.1 Compare the components of the biosynthetic and endocytic pathways.

Section Reference: Section 8.1 An Overview of the Endomembrane System

Question Type: Multiple Choice

2) The correct order of passage of materials produced in a biosynthetic pathway is: a) endoplasmic reticulum, Golgi complex, plasma membrane, secretory vesicle b) endoplasmic reticulum, Golgi complex, secretory vesicle, plasma membrane c) endoplasmic reticulum, lysosome, secretory vesicle, plasma membrane d) endoplasmic reticulum, lysosome, Golgi complex, plasma membrane Answer: b Difficulty: Hard Learning Objective: LO 8.1 Compare the components of the biosynthetic and endocytic pathways.

Section Reference: Section 8.1 An Overview of the Endomembrane System

Question Type: Multiple Choice

3) Production and transport of materials in secretory vesicles which occurs continuously is known as: a) regulated secretion b) endogenous secretion c) exogenous secretion d) constitutive secretion Answer: d Difficulty: Easy Learning Objective: LO 8.1 Compare the components of the biosynthetic and endocytic pathways.

Section Reference: Section 8.1 An Overview of the Endomembrane System

Question Type: Multiple Choice

4) What is the name for a brief incubation of a tissue with radioactivity during which labeled amino acids are incorporated into protein? a) chase b) pulse c) pulse-chase d) labelation Answer: b Difficulty: Easy Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

5) A tissue has been briefly labeled with radiolabeled amino acids. It is then transferred to a medium containing unlabeled amino acids. This can be done several times with different tissue samples for varying periods of time.

What is the entire procedure called?

a) chase b) pulse c) pulse-chase d) labelard e) statin Answer: c Difficulty: Easy Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

6) In a pulse-chase procedure, if the chase is longer, which statement below correctly describes the location of the radioactively labeled proteins in the cell? a) closer to the synthesis site b) farther from the nucleus c) farther from the synthesis site d) closer to the nucleus e) farther from the mitonchondria Answer: c Difficulty: Medium Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

7) A scientist wishes to visualize movement of a protein in a living cell. Which procedure would work best? a) pulse-chase b) fusion of the green fluorescent protein gene to the protein that is to be tracked through the cell c) fusion of the green fluorescent protein gene to the gene encoding the protein to be tracked through the cell d) pulse-chase using fluorescent antibodies e) all of these would work well

Answer: c Difficulty: Medium Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

8) Cells are infected with a vesicular stomatitis virus (VSV) strain in which a viral gene (VSVG) is fused to the green fluorescent protein gene. When the chimeric protein is synthesized, what pathway does it follow from synthesis until it leaves the cell? a) RER, Golgi complex, plasma membrane, viral envelopes b) RER, Golgi complex, viral envelopes, plasma membrane c) Golgi complex, RER, plasma membrane, viral envelopes d) RER, Golgi complex, mitochondria, plasma membrane, viral envelopes e) RER, mitochondria, Golgi complex, plasma membrane, viral envelopes Answer: a Difficulty: Hard Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

9) Cells are infected with a virus carrying a temperature-sensitive mutant VSVG gene that encodes a protein that cannot leave the ER of infected cells grown at restrictive temperatures (40oC). Thus, at higher temperatures: a) VSVG protein heads immediately for the Golgi complex. b) VSVG protein cannot leave the ER. c) VSVG protein leaves the ER immediately. d) all of the manufactured VSVG protein leaves the ER synchronously. e) VSVG protein is degraded rapidly and never passes to the Golgi complex.

Answer: b Difficulty: Hard

Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

10) Elevated temperatures at which temperature-sensitive mutants do not work are called ________ temperatures. a) restrictive b) permissive c) temperature-sensitive d) frame-shift e) point Answer: a Difficulty: Easy Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

11) When cells are homogenized, the cytomembrane system is broken into fragments, which can fuse to form small membranous spheres called ________. a) vacuoles b) victuals c) vesicles d) nuclei e) endosomes Answer: c Difficulty: Easy Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

12) The separation of organelles or vesicles derived from different organelles is called ______. a) cell division b) mitosis c) meiosis d) subcellular fractionation e) cell ostentation Answer: d Difficulty: Easy Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

13) When homogenized, the endomembrane system is broken up into vesicles, which are heterogeneous but similar in size. These vesicles can be purified and, after purification, often retain their biological activity. They are collectively referred to as _________. a) endosomes b) microsomes c) ribosomes d) minisomes e) lysosomes Answer: b Difficulty: Easy Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

14) Studies of cell physiology that occur in test tubes that do not contain whole cells are called: a) in vivo systems b) cell-free systems c) test tube systems d) onsite systems e) cellonic systems Answer: b Difficulty: Easy Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

15) Why are yeast cells often used to study eukaryotic gene mutations affecting secretion and other cytomembrane processes? a) They have only a few genes. b) They are small and single-celled and can be cultured easily. c) They can be grown as haploid organisms so mutants are easily seen. d) Deficiencies in yeast cells caused by mutants are easily detected. e) All of these are correct.

Answer: e Difficulty: Easy Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

16) What is the effect on a yeast cell of the presence of a mutant gene involved in vesicle fusion? a) The ER shrinks. b) The nucleus becomes swollen. c) The Golgi complex expands greatly.

d) Cells accumulate expanded ER cisternae. e) Cells amass an excess number of unfused vesicles.

Answer: e Difficulty: Medium Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

17) A cellular phenomenon called RNA interference (RNAi) is a process in which cells produce small RNAs called _________ bind to specific mRNAs and inhibit the translation of these mRNAs into proteins. a) snRNAs b) isRNAs c) mRNAs d) RNAsi e) siRNAs Answer: e Difficulty: Easy Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

18) A control cell that is synthesizing a GFP-labeled version of mannosidase II has fluorescence localized in the Golgi complexes of the cell. Normally, this enzyme is synthesized in the endoplasmic reticulum and moves via transport vesicles to the Golgi complex, where it takes up residence. If an experimental cell contains an siRNA that leads to the fluorescence being restricted to the endoplasmic reticulum, with what would the siRNA be likely to interfere? a) an mRNA that codes for a protein involved in the transport of the enzyme from the ER to the Golgi complex b) an rRNA that synthesizes the enzyme c) the synthesis of mannosidase II from its mRNA d) an mRNA that codes for a protein involved in the transport of the enzyme from the Golgi complex to the ER

e) an mRNA that codes for the enzyme Answer: a Difficulty: Hard Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

19) What allows smooth and rough vesicles (microsomes) to be readily separated by density gradient centrifugation? a) their size differences b) their differences in lipid composition c) their differences in color d) their differences in density e) their differences in water content Answer: d Difficulty: Medium Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Choice

20) What can be used to distinguish RER from SER? a) the location of the ER b) the proximity of the ER to the nucleus c) the protein make-up of the ER d) the shape of its component lipids Answer: c Difficulty: Medium

Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

21) RER has ribosomes, similarly to which structure that it is continuous with? a) the inner membrane of the nuclear envelope b) the outer membrane of the nuclear envelope c) the outer mitochondrial membrane d) the outer chloroplast membrane e) the Golgi complex Answer: b Difficulty: Easy Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

22) Which type of cells below is NOT known for its extensively developed SER? a) skin cells b) kidney tubule cells c) skeletal muscle cells d) steroid-producing endocrine cells e) both skeletal muscle cells and kidney tubule cells Answer: a Difficulty: Easy Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

23) What determines the function of a cell's smooth endoplasmic reticulum? a) its lipid content b) its polynucleotide content c) its carbohydrate content d) its protein content e) its age Answer: d Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

24) Which of the following is a function associated with the smooth endoplasmic reticulum in at least some cells? a) synthesis of steroid hormones b) detoxification of many organic compounds, like barbiturates and ethanol c) release of glucose into the bloodstream d) sequestration of calcium Ca2+ ions within the cisternal space e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

25) When the SER detoxifies compounds, what is one known potential problem? a) The detoxified compounds cause excessive weight gain. b) The detoxified compounds cause excessive weight loss. c) The detoxified compounds are carcinogenic. d) The detoxified compounds denature essential enzymes. e) Detoxification leads to addiction.

Answer: c Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

26) What cellular response is triggered by the regulated release of Ca2+ ions from the SER? a) skeletal muscle cell contraction b) secretory vesicle fusion with the plasma membrane c) release of neurotransmitters from nerve cells d) release of the contents of the acrosome from the head of a sperm Answer: a Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

27) What is the arrangement of organelles in a secretory cell from the basal end to the apical end, an arrangement that reflects the flow of secretory products from synthesis to discharge? a) nucleus and RER – SER – Golgi complex – secretory vesicles b) Golgi complex – nucleus and RER – SER – secretory vesicles

c) nucleus and RER – Golgi complex – SER – secretory vesicles d) SER – nucleus and RER – Golgi complex – secretory vesicles e) secretory vesicles – nucleus and RER – SER – Golgi complex Answer: a Difficulty: Hard Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

28) What are the two sites within a cell at which protein synthesis occurs? a) cytosolic surface of RER and cisternal surface of RER b) cytosolic surface of RER and free ribosomes c) cisternal surface of RER and free ribosomes d) free ribosomes and cytosolic surface of SER e) cytosolic surface of RER and cytosolic surface of SER Answer: b Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

29) Blobel, Sabatini and Dobberstein proposed that the site of protein synthesis is determined by information contained in the N-terminal portion of the protein, the first part to emerge from the ribosome. What did they call their proposal? a) the Chemiosmotic Hypothesis b) the Posttranslational Hypothesis c) the SRP Hypothesis d) the Signal Hypothesis

e) the Co-translational Hypothesis Answer: d Difficulty: Easy Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

30) What effect does the binding of the signal recognition particle (SRP) to the ribosome and the growing polypeptide chain have on protein synthesis? a) Protein synthesis accelerates. b) Protein synthesis ceases temporarily. c) Protein synthesis ceases permanently. d) Protein synthesis is terminated.

Answer: b Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

31) What appears to be the purpose of molecular chaperones like BiP? a) They recognize and bind to unfolded or misfolded proteins and help them attain their native structure. b) They recognize and bind to unfolded or misfolded DNAs and help them attain their native structure. c) They recognize and bind to unfolded or misfolded RNAs and help them attain their native structure. d) They recognize and bind unfolded or misfolded carbohydrates and help them attain their native shape. e) They transport secretory proteins into secretory vesicles.

Answer: a

Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

32) Why is the ER ideal as a port of entry for secretory proteins? a) The ER has a large surface area allowing for the attachment of many ribosomes. b) The ER cisternae lumen favors unfolding and disassembly of proteins. c) The RER can segregate secretory, lysosomal and cytoplasmic proteins from other newly made proteins, allowing their modification, and send them to their final destination. d) The ER has a small surface area, allowing critical peptides to be concentrated into vesicles.

Answer: a Difficulty: Hard Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

33) How do integral membrane proteins enter the lipid bilayer? a) They insert into the membrane from the RER lumen after their synthesis is complete. b) The aqueous translocon channel has a gate that continuously opens and closes, giving each nascent polypeptide segment a chance to partition itself into the lipid bilayer's hydrophobic core. c) They insert into the membrane from the cytosol after their synthesis is complete. d) The membrane is disrupted and proteins are incorporated during reassembly.

Answer: b Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

34) How is the orientation of membrane proteins in the membrane thought to be accomplished? a) After synthesis, an enzyme orients the protein properly. b) During synthesis, the translocon inner lining orients the nascent polypeptide so the more positive end faces the cytosol. c) During synthesis, the translocon inner lining orients the nascent polypeptide so the more negative end faces the cytosol. d) During synthesis, the translocon inner lining orients the nascent polypeptide so the more positive end faces the mitochondrial intermembrane space. e) After synthesis, the translocon inner lining orients the nascent polypeptide so the more positive end faces the cytosol.

Answer: b Difficulty: Hard Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

35) Which of the proteins below are NOT made on the membrane-bound ribosomes of the RER? a) peripheral proteins of the inner surface of the plasma membrane b) soluble lysosomal proteins c) vacuolar enzymes d) proteins of the extracellular matrix e) all of these are correct Answer: a Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

36) What evidence suggests that the translocon, by itself, can properly orient transmembrane segments? a) Purified components in cell-free systems show that the translocon, by itself, is capable of properly orienting transmembrane segments. b) Reconstituted translocons properly oriented membrane proteins in a natural membrane. c) Translocons orient proteins in red blood cells when exposed to them. d) Translocons bind to proteins in vitro. e) When translocons are missing, membrane proteins are not appropriately oriented.

Answer: a Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

37) When and where is the asymmetry of the phospholipid bilayers initially established? a) in the Golgi complex during lipid and protein modification b) in the ER during lipid and protein synthesis c) in the secretory vesicles during lipid and protein modification d) in the mitochondria by random insertion into the membranes e) all of these are correct Answer: b Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

38) Phospholipids are made by integral ER membrane enzymes whose active sites face the cytosol and they are inserted into the outer (cytoplasmic) leaflet of the ER membrane. How then do lipids destined for the luminal leaflet of the ER membrane get there? a) They diffuse freely into the luminal leaflet. b) There are enzymes called flippases that flip these lipids into the opposite leaflet later. c) They are disassembled on the cytoplasmic side and reassembled on the luminal side. d) They move to the cytoplasmic leaflet by osmosis. e) There are enzymes called translocases that flip these lipids into the opposite leaflet later.

Answer: b Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

39) What donates a sugar to the growing oligosaccharide chain of a glycoprotein? a) a complex carbohydrate b) a nucleotide peptide c) a nucleotide sugar d) a glycolipid Answer: c Difficulty: Easy Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

40) What enzyme transfers a block of sugars to asparagine residues of a polypeptide as it enters the RER? a) glycosyltransferase b) acid phosphatase c) oligosaccharyltransferase d) cellulose e) glycolase Answer: c Difficulty: Easy Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

41) To what residue of a polypeptide are N-linked oligosaccharide chains attached as that polypeptide enters the RER lumen through the translocon? a) arginine b) asparagine c) serine d) threonine e) ninhydrin Answer: b Difficulty: Easy Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

42) What is responsible for adding sugars to dolichol phosphate?

a) membrane-bound glycosyltransferases b) membrane-bound oligosaccharyltransferase c) membrane-bound gangliosidase d) glycosylsynthetase e) peptidyltransferase Answer: a Difficulty: Easy Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

43) CDG1b results from a deficiency in what enzyme? a) phosphomannose phosphatase b) phosphotungstate isomerase c) phosphomannose isomerase d) phosphatase e) phosphoenol pyruvate carboxylase Answer: c Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

44) Which correctly describes the effects and treatment of CDG1b? a) Mannose is unavailable for incorporation into oligosaccharides; oral supplements of mannose are the treatment. b) Mannose is overproduced for incorporation into oligosaccharides; oral supplements of mannose are the treatment.

c) Mannose is unavailable for incorporation into oligosaccharides; a diet free of mannose is the treatment. d) Mannose is overproduced for incorporation into oligosaccharides; a diet free of mannose is the treatment. e) Fructose is unavailable for incorporation into oligosaccharides; oral supplements of fructose are the treatment.

Answer: a Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

45) The oligosaccharide block that is added to secretory proteins after they enter the ER lumen goes through a number of modifications after its attachment. What is the first modification that occurs? a) addition of more sugars b) addition of glucose c) trimming of some sugars from the oligosaccharide block d) chemical modification of the sugars on the oligosaccharide chain e) both addition of more sugars and addition of glucose Answer: c Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

46) What happens to a newly synthesized glycoprotein after the binding of calnexin or calreticulin a) When the glycoprotein's folding is correctly completed, the remaining glucose on its oligosaccharide chain is eventually reduced and the glycoprotein is released from the chaperone. b) The oligosaccharide and amino acid chain are totally degraded. c) Correct folding of the glycoprotein is prevented until the chaperone is removed.

d) When the glycoprotein's folding is correctly completed, the remaining glucose on its oligosaccharide chain is removed enzymatically and the glycoprotein is released from the chaperone.

Answer: d Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

47) What does the conformation-sensing enzyme UGGT do if it binds to a misfolded or incompletely folded glycoprotein? a) It degrades the oligosaccharide chain. b) It adds a single mannose back to one of the glucose residues at the exposed end of the recently trimmed oligosaccharide. c) It adds a single glucose back to one of the mannose residues at the exposed end of the recently trimmed oligosaccharide. d) It degrades the protein. e) It refolds the protein on its own.

Answer: c Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

48) How does UGGT recognize incompletely folded or misfolded proteins that have been recently synthesized? a) Such proteins display exposed hydrophilic residues that are absent from properly folded proteins. b) Five histidine residues are exposed on the protein's surface when it is improperly folded. c) Such proteins display exposed hydrophobic residues that are absent from properly folded proteins. d) Six arginine residues are exposed on the protein's surface when it is improperly folded.

e) Such proteins display numerous carboxyl groups on their surfaces, which decreases their solubility.

Answer: c Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

49) What do studies suggest governs the "decision" to destroy a defective protein that has been unable to fold correctly and has been in the ER for an extended period of time? a) a fast-acting ER enzyme that trims a mannose residue from an exposed end of the oligosaccharide of a protein b) a slow-acting ER enzyme that trims a mannose residue from an exposed end of the oligosaccharide of a protein c) a fast-acting cytoplasmic enzyme that trims a mannose residue from an exposed end of the oligosaccharide of a protein d) a slow-acting nuclear enzyme that trims a mannose residue from an exposed end of the oligosaccharide of a protein e) a slow-acting cytoplasmic enzyme that trims a mannose residue from an exposed end of the oligosaccharide of a protein Answer: b Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

50) Where are misfolded secretory proteins eventually destroyed? a) in the RER b) in the SER c) in the Golgi complex d) in the cytosol (cytoplasm)

e) in the nucleus Answer: d Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

51) What is responsible for destroying misfolded proteins in the cytoplasm? a) polysomes b) polyribosomes c) peroxisomes d) proteasomes e) spliceosome Answer: d Difficulty: Easy Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

52) Why does the cell use proteasomes to destroy misfolded proteins? a) Destruction of misfolded proteins assures that aberrant proteins are not sent to other parts of the cell. b) These proteins can be degraded into components that can be used to make polynucleotides. c) These proteins are degraded into components that can be used to make polysaccharides. d) These proteins are degraded into components that are used to make lipids. e) Destruction of misfolded proteins prevents the dissolution of the plasma membrane.

Answer: a

Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

53) What initially happens if misfolded proteins are generated in the ER at a faster rate than they can be exported to the cytoplasm? a) They are degraded in the ER. b) They are inserted into the ER membrane. c) They are resynthesized in the ER. d) They accumulate in the ER. e) They accumulate in the Golgi complex.

Answer: d Difficulty: Easy Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

54) The accumulation of misfolded proteins in the ER is a potentially lethal situation and thus causes the triggering of what process? a) the unfolded protein response (UPR) b) the posttranscriptional response c) the polysomal response d) the proteasomal response e) the intracellular protein response Answer: a Difficulty: Easy

Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

55) The ER reportedly contains sensors that monitor the concentration of unfolded or misfolded proteins in the lumen. One proposal suggests that the sensors are normally kept in an inactive state by ______, particularly ______. a) molecular chaperones, ribosomes b) proteasomes, BiP c) molecular chaperones, BiP d) enzymes, ER e) molecular chaperones, Rubisco Answer: c Difficulty: Easy Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

56) What happens if the UPR is unsuccessful in relieving the stressful conditions in the cell? a) The cell grows. b) The cell divides. c) The cell-death pathway is triggered and the cell is destroyed. d) The cell shrinks. e) The cell's temperature is raised.

Answer: c Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

57) The movement of vesicular-tubular carriers (VTCs) farther away from the ER and toward the Golgi complex occurs along tracks composed of what material? a) RNA b) DNA c) microtubules d) microfilaments e) intermediate filaments Answer: c Difficulty: Easy Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Choice

58) Which part of the Golgi complex distinguishes between proteins to be shipped back to the ER and those that are allowed to proceed to the next Golgi station? a) the cis cisternae b) the cis-Golgi network (CGN) c) the medial cisternae d) the trans cisternae e) the trans-Golgi network (TGN) Answer: b Difficulty: Easy Learning Objective: LO 8.4 Explain the evidence supporting the cisternal maturation model and the vesicular transport model of Golgi function.

Section Reference: Section 8.4 The Golgi Complex

Question Type: Multiple Choice

59) What kind(s) of modifications are made in proteins as they move through the Golgi complex? a) The protein's carbohydrates are modified by a series of stepwise enzymatic reactions. b) Amino acids can be added to either end of the polypeptide chain. c) Amino acids in the proteins may be chemically altered into nucleic acids. d) Small segments of amino acids can be added into the center of an existing protein. e) All of these are correct.

Answer: a Difficulty: Medium Learning Objective: LO 8.4 Explain the evidence supporting the cisternal maturation model and the vesicular transport model of Golgi function.

Section Reference: Section 8.4 The Golgi Complex

Question Type: Multiple Choice

60) Which of the following carbohydrates is NOT synthesized in the Golgi complex? a) glycosaminoglycans in the animal extracellular matrix b) plant cell wall polysaccharides like pectin and hemicellulose c) the carbohydrates of glycolipids d) the carbohydrates of glycoproteins e) glycogen Answer: e Difficulty: Hard Learning Objective: LO 8.4 Explain the evidence supporting the cisternal maturation model and the vesicular transport model of Golgi function.

Section Reference: Section 8.4 The Golgi Complex

Question Type: Multiple Choice

61) What enzymes are responsible for determining the sequence of sugars added to growing oligosaccharide chains of membrane proteins or secretory proteins as they travel through the Golgi complex? a) glycosaminocosidases b) peptidyltransferases c) glycosyltransferases d) amylases e) Rubisco Answer: c Difficulty: Easy Learning Objective: LO 8.4 Explain the evidence supporting the cisternal maturation model and the vesicular transport model of Golgi function.

Section Reference: Section 8.4 The Golgi Complex

Question Type: Multiple Choice

62) What sugar is usually removed from the N-linked core oligosaccharide chains on proteins in the Golgi complex as opposed to the glucose residues trimmed off in the ER? a) glucose b) galactose c) mannose d) sialic acid e) fucose Answer: c Difficulty: Medium Learning Objective: LO 8.4 Explain the evidence supporting the cisternal maturation model and the vesicular transport model of Golgi function.

Section Reference: Section 8.4 The Golgi Complex

Question Type: Multiple Choice

63) What determines the sequence of sugar addition to glycoproteins traveling through the Golgi complex? a) Nothing - the sequence is random. b) the spatial arrangement of specific glycosyltransferases that contact proteins as they pass through the Golgi complex c) the concentration of sugars in the Golgi complex d) the concentration of proteins in the Golgi complex e) the sequence of nucleotides in the Golgi complex Answer: b Difficulty: Medium Learning Objective: LO 8.4 Explain the evidence supporting the cisternal maturation model and the vesicular transport model of Golgi function.

Section Reference: Section 8.4 The Golgi Complex

Question Type: Multiple Choice

64) Which of the models below suggests that the Golgi cisternae are transient structures that form at the cis face of the stack by fusion of membranous carriers from the ER and ERGIC and that each cisterna travels through the Golgi complex from the cis to the trans end of the stack, changing in composition as it progresses? a) the cisternal maturation model b) the cargo carrying model c) the vesicular transport model d) the secretory transport model e) the chemiosmotic model Answer: a Difficulty: Easy Learning Objective: LO 8.4 Explain the evidence supporting the cisternal maturation model and the vesicular transport model of Golgi function.

Section Reference: Section 8.4 The Golgi Complex

Question Type: Multiple Choice

65) Which model of Golgi complex formation suggests that the cisternae of a Golgi stack remain in place as stable compartments held together by a protein scaffold, while the cargo is shuttled through the Golgi via vesicles that bud from one compartment and fuse with a neighboring one? a) the cisternal maturation model b) the cargo carrying model c) the vesicular transport model d) the secretory transport model e) the chemiosmotic model Answer: c Difficulty: Easy Learning Objective: LO 8.4 Explain the evidence supporting the cisternal maturation model and the vesicular transport model of Golgi function.

Section Reference: Section 8.4 The Golgi Complex

Question Type: Multiple Choice

66) Vesicles that move through the Golgi complex from a trans-donor to a cis-acceptor membrane are said to move in a(n) __________ direction. a) astrograde b) anterograde c) retrograde d) posterograde e) vertigrade Answer: c Difficulty: Easy Learning Objective: LO 8.4 Explain the evidence supporting the cisternal maturation model and the vesicular transport model of Golgi function.

Section Reference: Section 8.4 The Golgi Complex

Question Type: Multiple Choice

67) Most vesicles budding from the Golgi body have a fuzzy, electron-dense coat on their ______ surface. The coat appears to be made of _______. a) luminal, protein b) cytosolic, protein c) luminal, lipid d) cytosolic, carbohydrate e) cytosolic, lipid Answer: b Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

68) Which components below are selected for transport by vesicles originating in the Golgi complex? a) secretory proteins b) lysosomal proteins c) proteins required to dock the vesicle to an acceptor membrane d) proteins required to target the vesicle to an acceptor membrane e) all of these components Answer: e Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

69) How do protein coats select the cargo molecules to be carried by the vesicles they help to form? a) They electromagnetically attract the correct cargo proteins. b) The protein coats have a specific affinity for the cytosolic tails of integral membrane proteins that reside in the donor membrane.

c) The coats have a specific affinity for the luminal tails of integral membrane proteins that reside in the donor membrane. d) The coat proteins directly attach to the cargo proteins in the lumen of the forming vesicles. e) The coat proteins attach to the extracellular matrix.

Answer: b Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

70) The coat of vesicles that transport materials around the cell interior ___________. a) is composed of three distinct protein layers b) is absent in vesicles moving in a retrograde direction c) possesses adaptors that are able to select specific cargo molecules d) possesses an outer layer of adaptors that serves primarily to bind the vesicle's cargo Answer: c Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

71) Which coated vesicles move materials in a retrograde direction from the ERGIC and Golgi stack backwards toward the ER? a) COPII-coated vesicles b) COPI-coated vesicles c) clathrin-coated vesicles d) cadmium-coated vesicles e) both COPII-coated vesicles and COPI-coated vesicles Answer: b

Difficulty: Easy Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

72) Which GTP-binding protein plays a regulatory role by initiating vesicle formation and by regulating the assembly of the vesicle's COPII coat? a) Sar1 b) Gar1 c) ARF1 (adenosylation ribose factor) d) Ras e) Src Answer: a Difficulty: Easy Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

73) Sec23 and Sec24 bind together to form a "banana-shaped" dimer. What is the purpose of this dimer? a) Because of its linear shape, it firms up the membrane. b) Because of its curved shape, the dimer puts pressure on the membrane surface to help it further bend into a curved bud. c) Because of its curved shape, the dimer puts pressure on the membrane surface to help it disintegrate. d) The dimer stabilizes the Golgi complex membrane. e) The dimer joins with other dimers to form a remarkably stable cage.

Answer: b Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

74) What is the primary adaptor protein of the COPII coat that interacts specifically with the ER export signals in the cytosolic tails of membrane proteins that are destined to traffic on to the Golgi complex? a) ARF1 b) Sec23 c) Sec24 d) Sec31 e) Sec13 Answer: c Difficulty: Easy Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

75) What happens to COPI-coated vesicles within the cell when the cell is treated with GTP analogues that can not be hydrolyzed? a) They accumulate in the nucleus. b) They accumulate in the cytoplasm. c) They fuse into one giant vesicle in the cytoplasm. d) They decrease substantially in number in the nucleus. e) They decreased substantially in number in the cytoplasm.

Answer: b Difficulty: Hard Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

76) What GTP-binding protein is associated with the formation of the COPI coat on COPI-coated vesicles? a) Sar1 b) Arf Arf c) Arf1 (adenosylation ribose factor) d) Ras e) Src Answer: c Difficulty: Hard Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

77) What is usually the retrieval signal for escaped ER membrane proteins? a) KKXX at the C-terminus of the protein b) KDEL at the C-terminus of the protein c) KDEL at the N-terminus of the protein d) KKXX at the N-terminus of the protein e) KXEL at the C-terminus of the protein Answer: b Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

78) Where in the Golgi complex does most protein sorting occur? a) the medial cisternae

b) the TGN c) the CGN d) the cis network e) the pre-Golgi network Answer: b Difficulty: Easy Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

79) What are the recognition signals for lysosomal enzymes that allow them to be localized correctly in lysosomes? a) Lysosomal enzymes possess sulfated mannose residues on N-linked carbohydrate chains. b) Lysosomal enzymes possess phosphorylated mannose residues on N-linked carbohydrate chains. c) Lysosomal enzymes possess phosphorylated mannose residues on O-linked carbohydrate chains. d) Lysosomal enzymes possess sulfated mannose residues on O-linked carbohydrate chains. e) Lysosomal enzymes possess phosphorylated glucose residues on N-linked carbohydrate chains.

Answer: b Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

80) What would happen if the enzyme that adds phosphate groups to the appropriate mannose residues on the carbohydrate chains of lysosomal enzymes were defective? a) Lysosomal enzymes would be localized to lysosomes. b) Lysosomal enzymes would be localized to peroxisomes. c) Lysosomal enzymes would continue through the Golgi complex to secretory vesicles and would eventually be secreted. d) Lysosomal enzymes would be degraded.

Answer: c Difficulty: Hard Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

81) Lysosomal enzymes are transported from the TGN in vesicles coated with what protein? a) clathrin b) lysozyme c) dynamin d) acid phosphatase e) COPII Answer: a Difficulty: Easy Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

82) What happens to the clathrin coat once the vesicle has budded from the Golgi body? a) It is lost. b) It is strengthened. c) It is rearranged. d) It is thickened. e) It swells.

Answer: a Difficulty: Easy Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

83) What acts as an address directing lysosomal enzymes to lysosomes? a) a lysosomal peptide b) mannose-6-sulfate residues on the enzyme c) mannose-6-phosphate residues on the enzyme d) a signal peptide on the enzyme e) a stroma transfer peptide on the enzyme Answer: c Difficulty: Easy Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

84) I-cell disease is typified by __________. a) lysosomes bloated with undegraded materials b) the production of normal levels of lysosomal enzymes without the mannose 6-phosphate residues normally present c) lysosomal enzymes being secreted by the cell because they have not been targeted to lysosomes d) a deficiency in N-acetylglucosamine phosphotransferase e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

85) In general, diseases that result from a deficiency of a single lysosomal enzyme are called ________. a) lysosomal dissociation disorders b) Tay-Sachs Disease c) lysosomal storage disorders d) ancestral disorders e) ancestral lysosomal disorders Answer: c Difficulty: Easy Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

86) Why does glucocerebrosidase taken into macrophages by receptor-mediated endocytosis end up in lysosomes? a) The enzyme travels through the cytoplasm to get to lysosomes. b) The enzyme denatures and then goes through a channel into lysosomes. c) Lysosomes are the natural target of enzymes taken into macrophages by endocytosis. d) Lysosomes adsorb glucocerebrosidase to their surfaces. e) Lysosomes pick up the enzyme from mitochondria.

Answer: c Difficulty: Hard Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

87) Why does targeting glucocerebrosidase to lysosomes in macrophages serve as a treatment for Gaucher's disease? a) Glucocerebrosidase is normally denatured in the lysosomes.

b) Glucocerebrosidase is delivered to the precise sites in the cell where the deficiency is manifested, correcting the deficit. c) Glucocerebrosidase denatures the cytoplasm from its location in the lysosomes, correcting the deficit. d) Glucocerebrosidase binds to the outer lysosome surface and breaks down glycogen in the cytoplasm. e) Glucocerbrosidase is supposed to digest most of the enzymes in the lysosome.

Answer: b Difficulty: Hard Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

88) Treatment of lysosomal storage diseases with enzyme replacement therapy involves _______. a) sending functional copies of the missing enzyme to the precise cell sites where the deficiency is manifested b) targeting mutant copies of the missing enzyme to the cell sites where the deficiency is manifested c) targeting functional copies of another enzyme to the cell sites where the deficiency is manifested d) administration of small molecular weight drugs to inhibit the synthesis of substances that accumulate in the disease e) administration of large molecular weight drugs to inhibit the synthesis of substances that accumulate in the disease Answer: a Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

89) Which molecule type is thought to direct the movement of vesicles through the cytoplasm to their final destination? a) microfilaments b) microtubules c) intermediate filaments

d) collagen e) keratin Answer: b Difficulty: Easy Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

90) What would happen to the movement of vesicles toward their eventual target if a microtubule inhibitor like colchicine were added to the cells? a) The vesicles would disintegrate. b) The vesicles would move faster. c) Vesicle movement would slow or stop. d) The vesicles would shrink. e) The vesicles would swell.

Answer: c Difficulty: Hard Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

91) How do Rabs associate with membranes? a) via microtubules b) via a lipid anchor c) via intermediate filaments d) via vimentin filaments e) via filaments Answer: b

Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

92) When Rabs have bound to GTP, what do they do? a) They fuse membranes directly. b) They pass through the membrane. c) They recruit specific cytosolic tethering proteins to specific membrane surfaces. d) They denature specific membrane proteins. e) They fuse to the nuclear membrane.

Answer: c Difficulty: Easy Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

93) Where is this common domain of SNAREs located, of what is it composed and what is it called? a) in the lumen, 60 – 70 amino acids that form a complex with another SNARE motif b) in the lumen, 60 – 70 nucleotides that form a complex with another SNARE motif c) in the cytosol, 60 – 70 amino acids that form a complex with another SNARE motif d) in the cytosol, 60 – 70 amino acids forming a complex with another SNARE coil e) in the cytosol, 60 – 70 carbohydrates forming a complex with another SNARE motif Answer: c Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

94) What are the two functional categories of SNAREs? a) v-SNAREs and g-SNAREs b) t-SNAREs and g-SNAREs c) v-SNAREs and t-SNAREs d) v-SNAREs and er-SNAREs e) er-SNAREs and g-SNAREs Answer: c Difficulty: Easy Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

95) V-SNAREs are found _______________and t-SNARES are found _________________: a) incorporated into transport vesicle membranes during budding, in target compartment membranes b) in target compartment membranes, incorporated into transport vesicle membranes during budding c) in target compartment membranes, in target compartment membranes d) incorporated into transport vesicle membranes during fusion, in target compartment membranes e) in target compartment membranes, incorporated into transport vesicle membranes during fusion Answer: a Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Choice

96) A ____________ is thought to dissociate the 4-stranded SNARE complex by attaching to the SNARE bundle and, using energy from ATP hydrolysis, twisting it apart.

a) doughnut-shaped, cytosolic protein called NSF b) doughnut-shaped, cytosolic protein called ARF1 c) doughnut-shaped, cytosolic protein called Rab d) cylindrical, cytosolic protein called NSF e) cylindrical, cytosolic protein called ARF1 Answer: a Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Select

97) You are working on a project in which you block autophagy in a particular portion of the brain of a laboratory animal. What happens to these animals? (Select all correct choices) a) Nothing happens since nerve cells are so long-lived. b) That region of the nervous system experiences a massive loss of nerve cells. c) There is slight, but not dangerous damage, to the organelles and proteins of the nerve cells. d) There is continuous damage to the proteins and organelles of these long-lived cells.

Answer: b, d Difficulty: Medium Learning Objective: LO 8.7 Explain the functions of lysosomes.

Section Reference: Section 8.7 Lysosomes

Question Type: Multiple Choice

98) Synaptic vesicle fusion to the presynaptic membrane in a neuron is regulated by what calcium-binding protein found in the membrane of the synaptic vesicle? a) synaptin b) synaptogenin c) calmodulin d) calcitonin

e) synaptotagmin Answer: e Difficulty: Easy Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Select

99) Which techniques are currently used to harvest extracellular vesicles for use in drug delivery research?

(Select all correct choices) a) extraction by ultracentrifugation b) isolation through affinity purification techniques c) creation of mutant gene product vesicles with therapeutic proteins inside them d) overexpression of therapeutic RNAs in vesicle-producing cells Answer: a, b, d Difficulty: Medium Learning Objective: LO 8.6 Describe the use of extracellular vesicles for drug delivery.

Section Reference: Section 8.6 Engineering Linkage: Extracellular Vesicles for Drug Delivery

Question Type: Multiple Choice

100) Which of these molecules is NOT transported in extracellular vesicles? a) cytoplasmic proteins b) membrane proteins c) DNA d) mRNA e) noncoding RNA Answer: c Difficulty: Easy Learning Objective: LO 8.6 Describe the use of extracellular vesicles for drug delivery.

Section Reference: Section 8.6 Engineering Linkage: Extracellular Vesicles for Drug Delivery

Question Type: Multiple Choice

101) Which is a limitation of using extracellular vesicles for drug delivery? a) detection by the immune system prevents delivery b) phagocytes degrade c) unable to move through the blood-brain barrier d) only able to transport nucleic acids Answer: b Difficulty: Medium Learning Objective: LO 8.6 Describe the use of extracellular vesicles for drug delivery.

Section Reference: Section 8.6 Engineering Linkage: Extracellular Vesicles for Drug Delivery

Question Type: Multiple Choice

102) Which of the following enzymes are typically found in lysosomes? a) hydrolytic enzymes (acid hydrolases) b) oxidoreductases c) transferases d) lyases e) ligases Answer: a Difficulty: Easy Learning Objective: LO 8.7 Explain the functions of lysosomes.

Section Reference: Section 8.7 Lysosomes

Question Type: Multiple Choice

103) Which pH below would be most likely to favor the operation of a lysosomal enzyme? a) 8.5 b) 7.6 c) 4.5 d) 11.3 e) 6.5 Answer: c Difficulty: Medium Learning Objective: LO 8.7 Explain the functions of lysosomes.

Section Reference: Section 8.7 Lysosomes

Question Type: Multiple Choice

104) What is thought to shield lysosomal membranes against attack by their enclosed enzymes? a) DNA b) basic RNA c) carbohydrate chains attached to integral membrane proteins d) carbohydrate chains attached to peripheral membrane proteins e) the lipid bilayer itself Answer: c Difficulty: Medium Learning Objective: LO 8.7 Explain the functions of lysosomes.

Section Reference: Section 8.7 Lysosomes

Question Type: Multiple Choice

105) What happens to the products of the breakdown of materials brought into a single-celled organism from the extracellular environment? a) They are used as nutrients and are released to the extracellular space. b) They are used as nutrients and are released into the cytoplasm. c) Peptides produced during digestion are posted on the cell surface.

d) They are used to build the nuclear envelope and are released into the cytoplasm. e) They are maintained within the lysosome and used for building new lysosomes.

Answer: b Difficulty: Easy Learning Objective: LO 8.7 Explain the functions of lysosomes.

Section Reference: Section 8.7 Lysosomes

Question Type: Multiple Choice

106) What process is responsible for organelle turnover in the cell and carries out the regulated destruction of the cell's own organelles for the purpose of recycling the components of which they are made? a) autolysis b) autophagolysosome c) apoptosis d) autophagy e) autonomy Answer: d Difficulty: Easy Learning Objective: LO 8.7 Explain the functions of lysosomes.

Section Reference: Section 8.7 Lysosomes

Question Type: Multiple Choice

107) Once an organelle to be destroyed, like a mitochondrion, has been surrounded with a double membrane, what is the name of the structure that has been produced? a) autophagolysosome b) phagolysosome c) bacteriophage d) phagosome e) autophagosome Answer: e

Difficulty: Easy Learning Objective: LO 8.7 Explain the functions of lysosomes.

Section Reference: Section 8.7 Lysosomes

Question Type: Multiple Choice

108) Once the digestive process in an autophagolysosome is completed, the organelle is called _____. If its contents are not eliminated from the cell by exocytosis and are instead retained within the cytoplasm indefinitely, it is called _______. a) a lipofuscin granule, a residual body b) a residual body, an autophagosome c) a residual body, a lipofuscin granule d) a lipofuscin granule, an autophagosome e) an autophagosome, a lipofuscin granule Answer: c Difficulty: Medium Learning Objective: LO 8.7 Explain the functions of lysosomes.

Section Reference: Section 8.7 Lysosomes

Question Type: Multiple Choice

109) Which of the following are proposed functions of autophagy? a) It plays a role in organelle turnover. b) It is used to cannibalize organelles when a cell is deprived of nutrients. c) It protects organisms against intracellular threats like abnormal protein aggregates and invading bacteria. d) It plays a role in the regulated destruction of the cell's own organelles and their replacement. e) All of the other answers are correct.

Answer: e Difficulty: Medium Learning Objective: LO 8.7 Explain the functions of lysosomes.

Section Reference: Section 8.7 Lysosomes

Question Type: Multiple Choice

110) Which of the following is NOT a function of plant cell vacuoles? a) stores many cell solutes and macromolecules b) distributes toxic compounds to the cytoplasm c) generates high turgor pressure that pushes outward against the cell wall and maintains cell shape d) site of intracellular digestion in a plant cell Answer: b Difficulty: Medium Learning Objective: LO 8.8 List the functions of plant cell vacuoles.

Section Reference: Section 8.8 Green Cells: Plant Cell Vacuoles

Question Type: Multiple Choice

111) All of the following toxic substances may be stored in plant vacuoles EXCEPT: a) strychnine b) glycosides containing cyanide c) digitalis d) glucosinolates containing cyanide Answer: a Difficulty: Easy Learning Objective: LO 8.8 List the functions of plant cell vacuoles.

Section Reference: Section 8.8 Green Cells: Plant Cell Vacuoles

Question Type: Multiple Choice

112) Plant vacuoles are lined by a membrane known as the:

a) turgorplast b) tumoplast c) tonoplast d) chloroplast Answer: c Difficulty: Easy Learning Objective: LO 8.8 List the functions of plant cell vacuoles.

Section Reference: Section 8.8 Green Cells: Plant Cell Vacuoles

Question Type: Multiple Choice

113) The vesicle containing material taken into the cell by phagocytosis is called _________. a) a phagocytosome b) a vacuolosome c) a phagosome d) a phagolysosome e) an exosome Answer: c Difficulty: Easy Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

114) What drives the engulfment of particulate material by phagocytosis? a) actin-containing microfilaments that underlie the plasma membrane b) tubulin-containing microtubules that underlie the plasma membrane c) actin-containing microfilaments that underlie the mitochondrial membrane d) myosin-containing microfilaments that underlie the plasma membrane e) tubulin-containing microtubules that underlie the mitochondrial membrane

Answer: a Difficulty: Medium Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

115) If you treated a macrophage with colchicine (a microtubular assembly inhibitor), what would likely happen to the rate of phagocytosis? What would likely happen to the rate of phagocytosis if you treated the macrophage with cytochalain B (an inhibitor of microfilament contractile activities)? a) Nothing would happen after colchicine exposure. The rate would rise after cytochalasin B exposure. b) The rate would drop after colchicine exposure. Nothing would happen after cytochalasin B exposure. c) Nothing would happen after colchicine exposure. The rate would drop after cytochalasin B exposure. d) The rate would rise after colchicine exposure. Nothing would happen after cytochalasin B exposure. e) Nothing would happen after treatment with either inhibitor.

Answer: c Difficulty: Hard Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

116) Which of the following strategies is used by Mycobacterium tuberculosis, the bacterium responsible for tuberculosis, to avoid being destroyed by phagocytosis? a) The bacterium crystallizes the enzymes in the phagolysosome. b) The bacterium inhibits fusion of the phagosome with a lysosome. c) The bacterium allows fusion with the lysosome, but neither the acidic pH nor the lysosomal enzymes can destroy it. d) The bacterium produces proteins that destroy lysosomal membrane integrity so that the bacterium can escape into the cell cytosol. e) The bacterium neutralizes the enzymes in the lysosome.

Answer: b

Difficulty: Medium Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

117) Which of the following is a difference between the coats of COPII- and clathrin-coated vesicles? a) The inner layer of adaptor proteins of COPII-coated vesicles overlap extensively, while those of clathrin-coated vesicles do not overlap. b) The outer scaffold subunits of the clathrin lattice of coated vesicles overlap extensively, while those of the COPII lattice of coated vesicles do not overlap. c) The outer scaffold subunits of the COPII lattice of coated vesicles overlap extensively, while those of the clathrin lattice of coated vesicles do not overlap. d) The clathrin-coated vesicles have three distinct layers, while the COPII-coated vesicles have two distinct layers.

Answer: b Difficulty: Medium Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

118) Which of the following strategies is used by Listeria monocytogenes, a bacterium that causes meningitis? a) The bacterium allows fusion with the lysosome, but the acidic pH cannot destroy it. b) The bacterium inhibits fusion of the phagosome with a lysosome. c) The bacterium allows fusion with the lysosome, but the lysosomal enzymes cannot destroy it. d) The bacterium produces proteins that destroy lysosomal membrane integrity so that the bacterium can escape into the cell cytosol. e) The bacterium neutralizes the enzymes in the lysosome.

Answer: d Difficulty: Medium

Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

119) What types of molecules below can a cell internalize by receptor-mediated endocytosis? a) hormones b) enzymes c) blood-borne proteins carrying certain nutrients d) growth factors e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

120) Substances that enter the cell by receptor-mediated endocytosis bind receptors that collect in specialized domains of the plasma membrane called ______. a) coated vesicles b) coated pits c) RME pits d) gap junctions e) tight junctions Answer: b Difficulty: Easy Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

121) The three-legged assembly of protein chains that makes up a clathrin molecule and that can assemble into a network of polygons resembling a honeycomb is called a _____. a) trigeminy b) triskeleton c) trigellium d) triskelion e) triskellium Answer: d Difficulty: Easy Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

122) The best-studied adaptors that participate in the formation of the coated pits and coated vesicles of clathrin-mediated endocytosis are the _____ adaptors. a) COPII b) GGA c) AP2 d) clathrin e) COPI Answer: c Difficulty: Easy Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

123) Which molecules do the AP2 adaptors of the clathrin coat connect? a) GGA adaptors and clathrin molecules b) the cytoplasmic tails of specific membrane receptors and clathrin molecules c) the luminal tails of specific membrane receptors and clathrin molecules d) the clathrin molecules and cargo molecules e) cargo molecules and the cytoplasmic tails of specific membrane receptors Answer: d Difficulty: Medium Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

124) Which molecule below is a GTP-binding protein that is required for the release of a clathrin-coated vesicle from the membrane on which it was formed? a) AP2 b) GGA c) clathrin d) dynamin e) opsonin Answer: d Difficulty: Easy Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

125) What helps to give different membrane compartments their own unique surface identity? a) the different proteins contained within them b) the different surface nucleotides in each one c) the different shapes of the different membrane compartments

d) the degree of concentration of the contents of the membrane compartments Answer: a Difficulty: Easy Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

126) The inner leaflet of the plasma membrane contains elevated levels of _____, which plays an important role in the recruitment of proteins involved in clathrin-mediated endocytosis, like dynamin and AP2. a) PI(4,5)P2 b) PI(4)P c) PI(3,5)P2 d) PI(3,4)P2 e) PI(5)P Answer: a Difficulty: Medium Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

127) Which endosomes are typically located in the more interior part of the cell, near the nucleus? a) late endosomes b) early endosomes c) medial lysosomes d) medial endosomes e) intellosomes Answer: a Difficulty: Easy

Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

128) Which of the differences between early and late endosomes outlined below is NOT correct? a) Early endosomes exchange their Rab5 proteins for Rab7 proteins as they transform into late endosomes. b) Late endosomes have a population of vesicles crowding their interior; early endosomes do not. c) Late endosomes exhibit a higher pH than early endosomes. d) In late endosomes, the outer boundary membrane has budded inward on its lumenal surface creating a group of vesicles. e) All of these are correct.

Answer: c Difficulty: Medium Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

129) What recognizes ubiquitinated signaling receptors and sorts them into the membranes that give rise to the internal vesicles of the late endosomes? a) ESCRT complexes b) CREST complexes c) ESCORT complexes d) RESCT complexes e) lysosomes Answer: a Difficulty: Easy Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

130) What leads to the degradation of the contents of late endosomes by lysosomal enzymes? a) secretion of lysosomal enzymes into late endosomes b) transport of lysosomal enzymes into late endosomes through specialized pore complexes c) fusion of late endosomes containing intralumenal vesicles with a lysosome d) fusion of early endosomes with lysosomes; late endosomes lowering their internal pH activating the enzymes e) late endosomes synthesizing lysosomal enzymes that then degrade the contents Answer: c Difficulty: Medium Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

131) People with Niemann-Pick type C disease suffer from what defect? a) They lack one of two lysosomal enzymes. b) They cannot degrade HDL particles. c) They cannot degrade LDL particles. d) They lack one of the proteins needed to transport cholesterol out of lysosomes. e) Their LDL receptors are nonfunctional.

Answer: d Difficulty: Medium Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

132) Drugs that lower blood LDL levels are referred to as _______.

a) olefins b) statins c) ancestrins d) cholestrins e) cholestrans Answer: b Difficulty: Easy Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

133) The drugs that lower LDL concentration in the blood function by ________. a) blocking a key cholesterol-degrading enzyme, HMG CoA reductase b) activating a key cholesterol-degrading enzyme, HMG CoA reductase c) blocking a key cholesterol synthesis enzyme, HMG CoA reductase d) activating a key cholesterol synthesis enzyme, HMG CoA reductase e) blocking a key cholesterol synthesis enzyme, HMG CoA oxidase Answer: c Difficulty: Medium Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

134) What protein is associated with HDL particles? a) Large LDL particle B-100 b) LDLenin c) apolipoprotein B-100 d) statin e) apolipoprotein A-1

Answer: e Difficulty: Medium Learning Objective: LO 8.9 Explain the processes involved in the bulk transport of materials into the cell.

Section Reference: Section 8.9 The Endocytic Pathway: Moving Membrane and Materials into the Cell Interior

Question Type: Multiple Choice

135) Which of the following organelles import(s) proteins through one or more outer boundary membranes? a) the nucleus b) mitochondria c) chloroplasts d) peroxisomes e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

136) How many subcompartments do peroxisomes have into which an imported protein can be placed? a) 1 b) 2 c) 3 d) 4 Answer: b Difficulty: Easy Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

137) Where does the peroxisomal targeting signal (PTS) receptor bind to peroxisome-destined proteins? a) in the nucleus b) in the cytoplasm (cytosol) c) in the mitochondrion d) in the peroxisome e) in the RER Answer: b Difficulty: Easy Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

138) Which of the following organelles imports proteins in their native, folded conformation? a) mitochondria b) chloroplasts c) peroxisomes d) nuclei e) lysosomes Answer: c Difficulty: Easy Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

139) How many mitochondrial subcompartments exist into which proteins can be delivered? a) 1 b) 2 c) 3 d) 4 e) 5 Answer: d Difficulty: Medium Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

140) Which of the following is a mitochondrial subcompartment into which proteins can be delivered? a) outer mitochondrial membrane (OMM) b) inner mitochondrial membrane (IMM) c) intermembrane space d) matrix e) all of these are correct Answer: e Difficulty: Easy Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

141) The targeting sequence of a mitochondrial-matrix protein is found at the molecule's N-terminus and includes a number of positively charged residues. What is this targeting sequence called? a) PTS b) mPTS c) signal peptide d) presequence e) mitochondrial targeting signal Answer: d Difficulty: Easy Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

142) The N-terminal targeting sequence of mitochondrial-matrix proteins is ultimately removed by _______ following import into the matrix. a) signal peptidase b) mitochondrial processing peptidase c) mitochondrial processing lipase d) mitochodrial signal peptidase e) mitochondrial signalase Answer: b Difficulty: Hard Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

143) What kind of molecules prepare polypeptides for mitochondrial uptake, including those that specifically direct mitochondrial proteins to the cytosolic surface of the outer mitochondrial membrane? a) proteases b) aggregases c) molecular chaperones d) carbohydrates e) pronases Answer: c Difficulty: Easy Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

144) What powers the movement of proteins into the mitochondrial matrix? a) electric potential across the inner mitochondrial membrane acting on the positively-charged targeting signal b) electric potential across the outer mitochondrial membrane acting on the positively-charged targeting signal c) ATP d) GTP e) electric potential across the inner mitochondrial membrane acting on the negatively-charged targeting signal Answer: a Difficulty: Medium Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

145) When a mitochondrial chaperone helps a mitochondrial matrix protein into the matrix by biased diffusion, the chaperone is said to be acting as ______.

a) a Brownian motion b) a biased diffuser c) a Brownian ratchet d) a misratchet e) an unbiased diffuser Answer: c Difficulty: Medium Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

146) How many subcompartments are there in chloroplasts into which proteins can be delivered? a) 1 b) 2 c) 6 d) 4 e) 5 Answer: c Difficulty: Medium Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

147) Which list below names the compartments into which chloroplast proteins can be imported? a) inner and outer chloroplast membranes, the intermembrane space, the stroma, thylakoid membranes, thylakoid lumen b) inner and outer chloroplast membranes, the intercristal space, the stroma, thylakoid membranes, thylakoid lumen

c) inner and outer chloroplast membranes, the intermembrane space, the cytoplasm, thylakoid membranes, thylakoid lumen d) inner and medial chloroplast membranes, the intermembrane space, the stroma, thylakoid membranes, thylakoid lumen e) inner and outer chloroplast membranes, the intermembrane space, the stroma, cristae membranes, thylakoid lumen Answer: a Difficulty: Hard Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

148) The outer and inner chloroplast membranes contain distinct translocation complexes named ________, respectively, that work together during protein import. a) Toc and Tic complexes b) Tic and Toc complexes c) Tick and Tock complexes d) Tock and Tick complexes e) Tock and Tic complexes Answer: a Difficulty: Medium Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

149) Most proteins destined for the chloroplast are synthesized with a removable ________ called the ______. a) N-terminal sequence, signal peptide b) C-terminal sequence, transit peptide

c) N-terminal sequence, transit peptide d) C-terminal sequence, signal peptide e) mid-chain sequence, transit peptide Answer: c Difficulty: Easy Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

150) Proteins that are destined to be translocated through the chloroplast envelope into the stroma must have a transit peptide including _______. a) a thylakoid transfer domain b) a thylakoid lumen domain c) a transit peptidase d) a stroma-targeting domain e) a matrix-targeting domain Answer: d Difficulty: Easy Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

151) What removes the stroma-targeting domain and where does the removal occur? a) a processing peptide synthase, stroma b) a processing peptidase, stroma c) a processing peptidase, thylakoid membrane d) a processing peptidase, thylakoid lumen e) a stromase, stroma

Answer: b Difficulty: Medium Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Choice

152) Many of the proteins that reside within the thylakoid membrane are encoded by chloroplast genes and synthesized on __________. a) ribosomes floating in the stroma b) ribosomes bound to the outer surface of the thylakoid membrane c) ribosomes bound to the inner chloroplast membrane d) ribosomes inside the thylakoid disks e) cytoplasmic ribosomes Answer: b Difficulty: Medium Learning Objective: LO 8.10 Describe how proteins are taken up by mitochondria, chloroplasts, and peroxisomes.

Section Reference: Section 8.10 Posttranslational Uptake of Proteins by Peroxisomes, Mitochondria, and Chloroplasts

Question Type: Multiple Select

153) The best characterized membrane contact site are: (Select all that apply) a) ER-mitochondria b) ER-Golgi c) ER-lysosome d) ER-peroxisome e) ER-chloroplast Answer: a, b

Difficulty: Medium Learning Objective: LO 8.1 Compare the components of the biosynthetic and endocytic pathways.

Section Reference: Section 8.1 An Overview of the Endomembrane System

Question Type: Multiple Select

154) Examples of regulated secretion include: (Select all correct choices) a) formation of extracellular matrix b) neurotransmitter secretion c) endocrine hormone secretion d) plasma membrane formation e) release of pancreatic exocrine digestive enzymes Answer: b, c, e Difficulty: Medium Learning Objective: LO 8.1 Compare the components of the biosynthetic and endocytic pathways.

Section Reference: Section 8.1 An Overview of the Endomembrane System

Question Type: Multiple Select

155) A cellular phenomenon called _________ is a process in which cells produce small RNAs that bind to specific mRNAs and inhibit the translation of these mRNAs into proteins. (Select all correct terms) a) RNAi b) cRNAs c) RNA interference d) RNAa Answer: a, c Difficulty: Medium Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Select

156) A control cell that is synthesizing a GFP-labeled version of mannosidase II has fluorescence localized in the numerous Golgi complexes of the cell. Normally, this enzyme is synthesized in the endoplasmic reticulum and moves via transport vesicles to the Golgi complex, where it takes up residence. What would an experimental cell look like if it contained an siRNA that led to the absence of one of the proteins involved in the transport of the enzyme from the ER to the Golgi complex? (Select all correct choices) a) Fluorescent label is not found in the Golgi complex. b) The GFP-mannosidase II is denatured so there is no fluorescent label anywhere in the cell. c) Fluorescent label still translocates to the Golgi complex completely. d) Fluorescent label is found only in the endoplasmic reticulum.

Answer: a, d Difficulty: Hard Learning Objective: LO 8.2 Describe five approaches used to study the endomembrane system.

Section Reference: Section 8.2 A Few Approaches to the Study of Endomembranes

Question Type: Multiple Select

157) Which of the following are enzymes involved in detoxification of organic compounds in the SER of liver cells? (Select all correct choices) a) oxygen-transferring enzymes b) oxygenases c) members of the cytochrome P450 family d) oxidases Answer: a, b, c Difficulty: Medium Learning Objective: LO 8.3 Compare the structures and functions of the RER and SER, and their roles in the maintenance of cellular proteins and membranes.

Section Reference: Section 8.3 The Endoplasmic Reticulum

Question Type: Multiple Select

158) Which subunits of the COPII coat bind to the vesicle membrane to form the outer structural cage of the protein coat? (Select all correct choices) a) Sec31 b) Sec24 c) Sec23 d) Sec13 Answer: a, d Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Question Type: Multiple Select

159) What is responsible for recognizing lysosomal enzymes and localizing them to the lysosomes? (Select all correct choices) a) mannose 6-phosphate receptors b) MPRs c) integral membrane proteins that span the TGN membranes d) intraGolgi receptors that reside in the TGN lumen Answer: a, b, c Difficulty: Medium Learning Objective: LO 8.5 Distinguish the functions of the different types of vesicle transport.

Section Reference: Section 8.5 Types of Vesicle Transport

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 9 Question Type: Multiple Choice 1) Which type of cytoskeletal element is characterized as a hollow, rigid cylindrical tube with walls composed of tubulin subunits? a) microfilaments b) microtubules c) intermediate filaments d) minitubules Answer: b Difficulty: Easy Learning Objective: LO 9.1 Describe the components and major functions of the cytoskeleton.

Section Reference: Section 9.1 Overview of the Major Functions of the Cytoskeleton 2) Which type of cytoskeletal element is described as tough, ropelike fibers composed of a variety of related proteins like keratin? a) actin filaments b) microtubules c) intermediate filaments d) macrofilaments e) indeterminate filaments Answer: c Difficulty: Easy Learning Objective: LO 9.1 Describe the components and major functions of the cytoskeleton.

Section Reference: Section 9.1 Overview of the Major Functions of the Cytoskeleton 3) Which element of the cytoskeleton is found in the cytoplasm AND the nucleus? a) actin filaments b) microtubules c) intermediate filaments d) macrofilaments e) indeterminate filaments

Answer: c Difficulty: Medium Learning Objective: LO 9.1 Describe the components and major functions of the cytoskeleton.

Section Reference: Section 9.1 Overview of the Major Functions of the Cytoskeleton 4) Which cytoskeletal element could be described as solid, thinner structures that are often organized into a branching network? a) actin filaments b) microtubules c) intermediate filaments d) macrotubules e) minifilaments Answer: a Difficulty: Easy Learning Objective: LO 9.1 Describe the components and major functions of the cytoskeleton.

Section Reference: Section 9.1 Overview of the Major Functions of the Cytoskeleton 5) You use an ionic detergent to extract materials from a cell. When you do, much of the mRNA stays behind with the cytoskeleton, which is not solubilized/depolymerized by this treatment.

What do these results mean? a) The cytoskeleton denatures in ionic detergents. b) The mRNA is solubilized by the ionic detergents. c) The mRNA is anchored to the cytoskeleton. d) The cytoplasm is anchored to the mRNA. e) The cytoskeleton is destabilized by the ionic detergent.

Answer: c Difficulty: Hard Learning Objective: LO 9.1 Describe the components and major functions of the cytoskeleton.

Section Reference: Section 9.1 Overview of the Major Functions of the Cytoskeleton 6) The splitting of the cytoplasm of a parent cell into two daughter cells is called ______. a) diakinesis b) cytokinesis c) mitosis

d) meiosis e) cytomegaly Answer: b Difficulty: Easy Learning Objective: LO 9.1 Describe the components and major functions of the cytoskeleton.

Section Reference: Section 9.1 Overview of the Major Functions of the Cytoskeleton 7) Which of the following describes functions performed by the cytoskeleton? a) provides structural support that determines cell shape and resists deforming forces b) positions various organelles within the cell interior c) provides a network of tracks over which materials like mRNA and organelles move within cells d) serves as a force-generating apparatus that moves cells from one place to another e) all of these choices are correct Answer: e Difficulty: Medium Learning Objective: LO 9.1 Describe the components and major functions of the cytoskeleton.

Section Reference: Section 9.1 Overview of the Major Functions of the Cytoskeleton 8) Which of the following is most extensible? a) intermediate filaments b) microtubules c) actin filaments d) spindle fibers e) microtubules and spindle fibers Answer: a Difficulty: Easy Learning Objective: LO 9.1 Describe the components and major functions of the cytoskeleton.

Section Reference: Section 9.1 Overview of the Major Functions of the Cytoskeleton 9) In cell biology and with respect to microtubules, intermediate filaments, and actin filaments, the word "dynamic" means ________. a) impressive b) constant in structure

c) ever-changing in structure d) energetic e) forceful Answer: c Difficulty: Medium Learning Objective: LO 9.1 Describe the components and major functions of the cytoskeleton.

Section Reference: Section 9.1 Overview of the Major Functions of the Cytoskeleton

10) Which of the following would be the most direct method to label microtubules with a fluorescent dye? a) injecting tubulin with a fluorescent dye b) attaching a fluorescently-labeled antibody to tubulin c) attaching a fluorescently-labeled antibody to actin d) inducing a cell to express the gene for tubulin that has been fused to the gene for GFP e) attaching a fluorescently-labeled antibody to tubulin and inducing a cell to express the gene for tubulin that has been fused to the gene for GFP Answer: b Difficulty: Hard Learning Objective: LO 9.2 Describe the structure and the functions of microtubules.

Section Reference: Section 9.2 Structure and Function of Microtubules 11) The microtubule wall is composed of globular proteins arranged in longitudinal rows called _________. a) actin filaments b) protofilaments c) prototubules d) prototubulins e) microtubular units Answer: b Difficulty: Medium Learning Objective: LO 9.2 Describe the structure and the functions of microtubules.

Section Reference: Section 9.2 Structure and Function of Microtubules 12) In a normal microtubule, how many protofilaments make up its cylindrical wall?

a) 13 b) 15 c) 11 d) 9 e) 17 Answer: a Difficulty: Easy Learning Objective: LO 9.2 Describe the structure and the functions of microtubules.

Section Reference: Section 9.2 Structure and Function of Microtubules 13) What kinds of forces hold microtubular structure together? a) strong interactions b) noncovalent interactions c) covalent interactions d) magnetism e) strong interactions and covalent interactions Answer: b Difficulty: Easy Learning Objective: LO 9.2 Describe the structure and the functions of microtubules.

Section Reference: Section 9.2 Structure and Function of Microtubules 14) When the MAP protein tau has abnormally high levels of __________, it is associated with the development of strange, tangled filaments called _________ that have been seen in the brains of patients suffering from several fatal neurodegenerative diseases like Alzheimer's disease. a) phosphorylation, neurofibrillary tangles b) phosphorylation, neurofibrillary anastomoses c) dephosphorylation, neurofibrillary tangles d) dephosphorylation, neurofibrillary anastomoses e) amination, neurofibrillary tangles Answer: a Difficulty: Medium Learning Objective: LO 9.2 Describe the structure and the functions of microtubules.

Section Reference: Section 9.2 Structure and Function of Microtubules

15) Given that axons growing out of a neuron require the outward growth of microtubules to support the lengthening axon, what would be likely to happen to axons growing out from a neuron when they are exposed to colchicine or nocodazole? a) Axons would grow more rapidly. b) Axonal outgrowth would cease. c) Axons would branch more often. d) Axonal outgrowth would change direction more frequently. e) There would be no change in axonal outgrowth.

Answer: b Difficulty: Medium Learning Objective: LO 9.2 Describe the structure and the functions of microtubules.

Section Reference: Section 9.2 Structure and Function of Microtubules 16) How are microtubules thought to affect cell shape in plants? a) Microtubules of the plant cell cortex are thought to affect the movement of cellulosesynthesizing enzymes in the cell membrane, which, in turn, affect cell wall growth and shape. b) Microtubules of the plant cell vacuole are thought to affect the movement of cellulosesynthesizing enzymes in the cell membrane, which, in turn, affect cell wall growth and shape. c) Microtubules of the plant cell cortex are thought to affect the movement of lipid-synthesizing enzymes in the cell membrane, which, in turn, affect cell wall growth and shape. d) Microtubules of the plant cell wall are thought to affect the movement of cellulosesynthesizing enzymes in the cell membrane, which, in turn, affect cell wall growth and shape. e) Microtubules of the plant cell nucleus are thought to affect the movement of cellulosesynthesizing enzymes in the cell membrane, which, in turn, affect cell wall growth and shape.

Answer: a Difficulty: Hard Learning Objective: LO 9.2 Describe the structure and the functions of microtubules.

Section Reference: Section 9.2 Structure and Function of Microtubules 17) In a growing plant cell, cellulose microfibrils are oriented _______ the direction of cell growth. a) in the same direction as b) perpendicular to c) parallel to d) diagonally to e) horizontal to

Answer: b Difficulty: Easy Learning Objective: LO 9.2 Describe the structure and the functions of microtubules.

Section Reference: Section 9.2 Structure and Function of Microtubules 18) How are proteins and neurotransmitters usually transported down the axon of a nerve cell? a) individually by diffusion b) in groups of ten c) inside transport vesicles d) inside the Golgi complex e) tied individually to microtubules Answer: c Difficulty: Medium Learning Objective: LO 9.2 Describe the structure and the functions of microtubules.

Section Reference: Section 9.2 Structure and Function of Microtubules 19) Structures that move from the cell body of a neuron down the axon toward the neuron terminals are said to move in _________ direction. a) retrograde b) anterograde c) astronomical d) radial e) intergrade Answer: b Difficulty: Easy Learning Objective: LO 9.2 Describe the structure and the functions of microtubules.

Section Reference: Section 9.2 Structure and Function of Microtubules 20) Left or right handed spiral growth in Arabidopsis has been linked to all of the following proteins EXCEPT: a) α tubulin b) β tubulin c) plant specific MAPs d) actin e) all of these proteins have been linked to spiral growth

Answer: d Difficulty: Easy Learning Objective: LO 9.3 Identify the role of microtubules in the spiral growth of plants.

Section Reference: Section 9.3 Green Cells: Why The Woodbine Twineth 21) The enzyme whose activity is altered when microtubule arrangements are misaligned, leading to spiral Arabidopsis growth is: a) SPIRAL1 b) cellulose synthetase c) plant specific MAP d) SPIRAL2 e) microfibril synthetase Answer: b Difficulty: Medium Learning Objective: LO 9.3 Identify the role of microtubules in the spiral growth of plants.

Section Reference: Section 9.3 Green Cells: Why The Woodbine Twineth 22) Point mutations in α or β tubulin which are associated with spiral growth in Arabidopsis plants are often located at a) sites of lipid-protein interaction b) sites of sugar-protein interaction c) sites of nucleic acid-protein interaction d) sites of protein-protein interaction Answer: d Difficulty: Medium Learning Objective: LO 9.3 Identify the role of microtubules in the spiral growth of plants.

Section Reference: Section 9.3 Green Cells: Why The Woodbine Twineth 23) Which of the following molecular motors are associated with actin filaments? a) kinesins b) dyneins c) myosins d) kinesins and dyneins c) kinesins and myosins

Answer: c Difficulty: Easy Learning Objective: LO 9.4 Explain how kinesins and dyneins function as motor proteins within a cell.

Section Reference: Section 9.4 Motor Proteins: Kinesins and Dyneins 24) Which of the following molecular motors are known to travel in a retrograde direction along microtubules? a) kinesins b) dyneins c) myosins d) kinesins and myosins e) kinesins and dyneins Answer: b Difficulty: Easy Learning Objective: LO 9.4 Explain how kinesins and dyneins function as motor proteins within a cell.

Section Reference: Section 9.4 Motor Proteins: Kinesins and Dyneins 25) Which of the following molecular motors are known to travel in an anterograde direction along microtubules? a) kinesins b) dyneins c) myosins d) kinesins and dyneins e) kinesins and myosins Answer: a Difficulty: Easy Learning Objective: LO 9.4 Explain how kinesins and dyneins function as motor proteins within a cell.

Section Reference: Section 9.4 Motor Proteins: Kinesins and Dyneins 26) What is the direct source of energy that powers molecular motors? a) hydrolysis of GTP

b) hydrolysis of ATP c) a proton gradient d) an H+ gradient e) condensation of ATP Answer: b Difficulty: Easy Learning Objective: LO 9.4 Explain how kinesins and dyneins function as motor proteins within a cell.

Section Reference: Section 9.4 Motor Proteins: Kinesins and Dyneins 27) What part of the molecular motor kinesin is responsible for binding to the cargo to be hauled? a) the motor domain b) the neck c) the rod-like stalk d) the fan-shaped tail e) the motor domain and the neck Answer: d Difficulty: Easy Learning Objective: LO 9.4 Explain how kinesins and dyneins function as motor proteins within a cell.

Section Reference: Section 9.4 Motor Proteins: Kinesins and Dyneins 28) Kinesin movement along a microtubule is said to be highly ________ meaning that it can move considerable distances along an individual microtubule without falling off. a) excessive b) processive c) depressive d) progressive e) egressive Answer: b Difficulty: Easy Learning Objective: LO 9.4 Explain how kinesins and dyneins function as motor proteins within a cell.

Section Reference: Section 9.4 Motor Proteins: Kinesins and Dyneins

29) Motor proteins are able to generate force by ___________. a) undergoing a series of conformational changes b) polymerization of protofilaments c) deploymerization of protofilaments d) adding amino acids to the end of the molecular motor e) making bonds AND adding amino acids to the end of the molecular motor Answer: a Difficulty: Medium Learning Objective: LO 9.4 Explain how kinesins and dyneins function as motor proteins within a cell.

Section Reference: Section 9.4 Motor Proteins: Kinesins and Dyneins 30) The simplest and the original assumption about step size for molecular motors was that as the motor protein walked along the actin or microtubule polymer it would step__________. a) 10 nm for every ATP that was hydrolyzed whether it was traveling along actin or tubulin b) the distance of one tubulin dimer or actin subunit for every 2 ATPs that were hydrolyzed c) the distance of three tubulin dimers or actin subunits for every ATP that was hydrolyzed d) varying distances along the cytoskeletal polymer for every ATP that was hydrolyzed e) the distance of one tubulin dimer or actin subunit for every ATP that was hydrolyzed Answer: e Difficulty: Medium Learning Objective: LO 9.4 Explain how kinesins and dyneins function as motor proteins within a cell.

Section Reference: Section 9.4 Motor Proteins: Kinesins and Dyneins 31) In order to measure the step size of kinesin, a group of investigators attached a small silica bead to the tail of a kinesin molecule. What advantage(s) did the attached silica bead provide? a) The bead made kinesin activity visible to the naked eye. b) The bead helped to denature kinesin making its properties easier to measure. c) The bead provided a handle for binding antibodies. d) The bead absorbed laser light in a manner proportional to the distance the motor moved. e) The bead made kinesin activity trackable and provided a handle for manipulating and holding the motor using an optical trap.

Answer: e

Difficulty: Hard Learning Objective: LO 9.4 Explain how kinesins and dyneins function as motor proteins within a cell.

Section Reference: Section 9.4 Motor Proteins: Kinesins and Dyneins 32) Nucleation of microtubules takes place rapidly inside a cell, where it occurs in association with a variety of specialized structures called _____________. a) MTOCs b) the centrosome c) basal bodies d) microtubule-organizing centers e) all terms are correct Answer: e Difficulty: Easy Learning Objective: LO 9.5 Explain the activities that occur at microtubule-organizing centers (MTOCs) and the underlying basis of microtubule dynamics.

Section Reference: Section 9.5 Microtubule-Organizing Centers (MTOCs) 33) What end of a microtubule is associated with the centrosome? a) the plus end b) the minus end c) the 5'-end d) the 3'-end e) the 0-end Answer: b Difficulty: Easy Learning Objective: LO 9.5 Explain the activities that occur at microtubule-organizing centers (MTOCs) and the underlying basis of microtubule dynamics.

Section Reference: Section 9.5 Microtubule-Organizing Centers (MTOCs) 34) Which MTOC gives rise to cilia and flagella? a) a centrosome b) basal bodies c) centriole d) PCM e) the plus end

Answer: b Difficulty: Easy Learning Objective: LO 9.5 Explain the activities that occur at microtubule-organizing centers (MTOCs) and the underlying basis of microtubule dynamics.

Section Reference: Section 9.5 Microtubule-Organizing Centers (MTOCs) 35) The sperm basal body becomes ______________. a) a basal body of the fertilized egg b) pericentriolar material c) five microtubules d) a flagellum of the later embryo e) a centriole Answer: e Difficulty: Easy Learning Objective: LO 9.5 Explain the activities that occur at microtubule-organizing centers (MTOCs) and the underlying basis of microtubule dynamics.

Section Reference: Section 9.5 Microtubule-Organizing Centers (MTOCs) 36) A small zone of fluorescent microtubules in a cell is photobleached so that their fluorescent label gives off no light. Some time later fluorescence returns to the bleached zone in the cell.

Which of the following is a possible explanation for the recovery of fluorescence in the region of the cell previously bleached? a) the dynamics of the microtubules turning over in that bleached zone of the cell b) the growth of new microtubules into the bleached zone c) movement of microtubules through the bleached zone d) the dynamics of the microtubules turning over in that bleached zone of the cell and the growth of new microtubules into the bleached zone e) all of these choices Answer: e Difficulty: Medium Learning Objective: LO 9.5 Explain the activities that occur at microtubule-organizing centers (MTOCs) and the underlying basis of microtubule dynamics.

Section Reference: Section 9.5 Microtubule-Organizing Centers (MTOCs) 37) Which of the following treatments do/does NOT disassemble microtubules in living cells?

a) slightly elevated temperature b) hydrostatic pressure c) elevated Ca2+ion concentration d) colchicine or vinblastine treatment e) all of these choices disassemble microtubules in living cells Answer: a Difficulty: Medium Learning Objective: LO 9.5 Explain the activities that occur at microtubule-organizing centers (MTOCs) and the underlying basis of microtubule dynamics.

Section Reference: Section 9.5 Microtubule-Organizing Centers (MTOCs) 38) Why are taxol, vinblastine and other similar drugs used as chemotherapy agents? a) They preferentially affect actively dividing cells, like tumor cells. b) They stabilize tumor cells. c) They disrupt tumor cell membranes. d) They prevent the entry of cells into the first stage of meiosis. e) They inhibit mitochondria.

Answer: a Difficulty: Medium Learning Objective: LO 9.5 Explain the activities that occur at microtubule-organizing centers (MTOCs) and the underlying basis of microtubule dynamics.

Section Reference: Section 9.5 Microtubule-Organizing Centers (MTOCs) 39) Which of the following treatments did not help microtubules to polymerize when homogenates prepared from brain tissue received it? a) Mg2+ ions b) GTP c) EGTA d) a temperature of 37°C e) a temperature of 4°C Answer: e Difficulty: Hard Learning Objective: LO 9.5 Explain the activities that occur at microtubule-organizing centers (MTOCs) and the underlying basis of microtubule dynamics.

Section Reference: Section 9.5 Microtubule-Organizing Centers (MTOCs)

40) Which of the following is a plausible explanation for the fact that the chemical EGTA blocks microtubule disassembly? a) EGTA binds to Ca2+ ions, which are known to induce microtubule depolymerization. b) EGTA binds to Mg2+ ions, which are known to induce microtubule depolymerization. c) EGTA binds to Ca2+ ions, which are known to induce microtubule polymerization. d) EGTA destroys Ca2+ ions, which are known to inhibit microtubule polymerization. e) EGTA destroys Mg2+ ions, which are known to inhibit microtubule polymerization.

Answer: a Difficulty: Hard Learning Objective: LO 9.5 Explain the activities that occur at microtubule-organizing centers (MTOCs) and the underlying basis of microtubule dynamics.

Section Reference: Section 9.5 Microtubule-Organizing Centers (MTOCs) 41) To which end of microtubules are tubulin subunits primarily added in vitro? a) the minus end b) the N-terminal end c) the plus end d) the C-terminal end e) the 5'-end Answer: c Difficulty: Easy Learning Objective: LO 9.5 Explain the activities that occur at microtubule-organizing centers (MTOCs) and the underlying basis of microtubule dynamics.

Section Reference: Section 9.5 Microtubule-Organizing Centers (MTOCs) 42) Which of the following is NOT a function of cilia? a) moving the cell from place to place b) moving fluid and particulate material past the cell c) sensing and monitoring the properties of extracellular fluids d) moving vesicles down the nerve cell axon e) All of these choices are functions of cilia.

Answer: d Difficulty: Medium

Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella 43) The core of a cilium is called the ________. a) troponeme b) dynomeme c) cilioneme d) axoneme e) flagelloneme Answer: d Difficulty: Easy Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella

44) Which of the following is normally associated with the cilia of organisms from protists to mammals? a) a 9 + 0 pattern b) a 9 + 1 pattern c) a 9 + 2 pattern d) a 9 + 3 pattern e) none of these choices Answer: c Difficulty: Easy Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella 45) The peripheral doublets of the axoneme are connected to one another by a(n) ________ composed of an elastic protein-based linkage called the _______. a) intersheath bridge, nexin link b) peridoublet sheath, dynein link c) interdoublet bridge, nexin link d) interdoublet sheath, dynein link

e) peridoublet sheath, nexin link Answer: c Difficulty: Medium Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella 46) What protein is responsible for intraflagellar transport of IFT trainsback toward the cell body? a) kinesin-II b) myosin c) cytoplasmic dynein d) kinesin e) cytoplasmic kinesin Answer: c Difficulty: Easy Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella 47) Treatment of isolated spermaxonemes with 0.6 M NaClhas been shown to selectively remove the outer arms from the A microtubules of the axoneme, leaving the inner arms in place. What would be the most likely effect on the NaCl-treated axoneme when ATP was added to the medium? a) The axoneme would fall apart completely. b) The axonemes would beat at about half the rate of the intact axoneme. c) The central microtubules would disassemble leaving the rest of the axoneme intact. d) The axoneme would be solubilized. e) Every element of the axoneme would be permanently cross-linked.

Answer: b Difficulty: Hard Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella

48) EDTA is a chemical that binds to and removes (chelates) divalent cations from solution.

Treatment of isolated axonemes with EDTA leads to the removal of the inner and outer arms extending from the A microtubules of the axoneme. Which of the following statements would appear to be true based on this information? a) Potassium ions are required for dynein to bind to the A tubules of the axoneme. b) Chlorine ions are required for dynein to bind to the A tubules of the axoneme. c) Magnesium ions are required for dynein to bind to the A tubules of the axoneme. d) Magnesium ions are required for tubulin to bind to the A tubules of the axoneme. e) Sodium ions are required for tubulin to bind to the A tubules of the axoneme.

Answer: c Difficulty: Hard Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella 49) The _______ link is an elastic protein-based linkage that connects tubulin doublets in cilia and flagella. The resultant bridges play an important role in ciliary and flagellar movement by limiting the extent that adjacent doublets can slide over one another. The resistance to sliding provided by these bridges causes the axoneme to bend. a) plectin b) filamentin c) nexin d) vimentin e) myosin Answer: c Difficulty: Easy Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella 50) ___________ are recently discovered diseases that result from organelle dysfunction.

Specifically, each of these diseases is a set of seemingly unrelated disease symptoms that all result from defects in cilia. a) Flagellopathies b) Cilioflagellar diseases c) Ciliopathies d) Ciliary diseases e) Pathophysicilias

Answer: c Difficulty: Easy Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella 51) For a long time, it was thought that cilia on most cells were unimportant or _________, despite their presence on almost all cells. This idea arose because the cilia on most cells are nonmotile, and it was assumed that motility was the key function of cilia. a) flagellar b) execrable c) ciliopathic d) vestigial e) vestibular Answer: d Difficulty: Easy Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella

52) Bardet-Biedl syndrome (BBS) is caused by mutations in any one of a number of genes that affect protein trafficking into cilia. Persons afflicted with BBS exhibit a remarkable range of abnormalities, like polydactyly, obesity, kidney disease, etc. These disparate symptoms are thought to reflect the function of cilia ________________. a) as sensors for a magnetic field b) as locomotory organelles c) as sources of flagella d) as binding sites for actin e) as antennas to receive signals that regulate development and physiology Answer: e Difficulty: Medium Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella 53) If there is no flow of extraembryonic fluid over a mouse embryo, ___________.

a) most of the embryos die early in development b) the majority of embryos still orient correctly c) the left-right asymmetry decision for the embryo is made at random d) the majority of embryos exhibit situs inversus e) the embryos exhibit no asymmetrical arrangement of organs Answer: c Difficulty: Easy Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella 54) Researchers worked with mouse embryos that had non-motile cilia and used a pump to drive an artificially created flow over their surface. When the flow was leftward directed, the mice developed _____________. a) normal organ positions b) situsinversus c) randomly placed organ positions d) abnormally; embryos died fairly early in development e) into identical twin embryos Answer: a Difficulty: Medium Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella 55) The cilia-driven flow in human and mouse embryos is detected by ___________. a) renin b) the Na+-K+ pump c) polycystins d) polyphenylin e) cysteine Answer: c Difficulty: Easy Learning Objective: LO 9.6 Explain how the movement of cilia and flagella relates to their structure and function.

Section Reference: Section 9.6 Structure and Function of Cilia and Flagella

56) The cross-bridges that hold intermediate filaments together are composed of _______. a) filamentin b) plectin c) ascriptin d) dynein e) myosin Answer: b Difficulty: Easy Learning Objective: LO 9.7Describe the structure and functions of intermediate filaments.

Section Reference: Section 9.7 Intermediate Filaments 57) The central, rod-shaped domain of an intermediate filament is flanked on each side by globular domains of variable size and sequence. What structure forms the core of the central, rod-shaped domain? a) alpha-helix b) beta-pleated sheet c) double helix d) quaternary coil e) coiled coil Answer: a Difficulty: Easy Learning Objective: LO 9.7 Describe the structure and functions of intermediate filaments.

Section Reference: Section 9.7 Intermediate Filaments 58) Which property below is most characteristic of intermediate filaments? a) elastic b) highly resistant to shrinkage c) springy d) ability to absorb mechanical stresses applied by the extracellular environment e) inflexible Answer: d Difficulty: Easy Learning Objective: LO 9.7 Describe the structure and functions of intermediate filaments.

Section Reference: Section 9.7 Intermediate Filaments 59) You inject labeled keratin subunits into cultured skin cells. What happens a few minutes later? a) The keratin subunits remain in the cytoplasmic keratin subunit pool. b) Filaments become labeled at sites scattered throughout their length, rather than at their ends. c) Filaments become labeled at both ends simultaneously. d) Filaments become labeled at one end exclusively. e) The entire intermediate filament network is quickly labeled.

Answer: b Difficulty: Hard Learning Objective: LO 9.7 Describe the structure and functions of intermediate filaments.

Section Reference: Section 9.7 Intermediate Filaments 60) Which protein below is often a component of intermediate filaments? a) alpha-tubulin b) beta-tubulin c) actin d) keratin e) myosin Answer: d Difficulty: Easy Learning Objective: LO 9.7 Describe the structure and functions of intermediate filaments.

Section Reference: Section 9.7 Intermediate Filaments 61) What seems to control the assembly and disassembly of intermediate filaments? a) denaturation b) sulfation c) phosphorylation and dephosphorylation d) hydrolysis e) hydroxylation Answer: c Difficulty: Easy Learning Objective: LO 9.7 Describe the structure and functions of intermediate filaments.

Section Reference: Section 9.7 Intermediate Filaments 62) With which of the following structures are intermediate filaments associated? a) the nuclear envelope in the center of the cell b) hemidesmosomes c) desmosomes d) the neurofilaments of neuronal axons e) all of these choices are correct Answer: e Difficulty: Medium Learning Objective: LO 9.7 Describe the structure and functions of intermediate filaments.

Section Reference: Section 9.7 Intermediate Filaments 63) What kind of cells seems to rely mostly on microfilaments for long-distance transport of cytoplasmic vesicles and organelles, probably due to restricted microtubule distribution in these cells? a) red blood cells b) white blood cells c) plant cells d) neurons e) muscle cells Answer: c Difficulty: Easy Learning Objective: LO 9.8 Explain the structure and function of actin and myosin and how they interact.

Section Reference: Section 9.8 Actin and Myosin 64) Which of the following words best describes the structure of an actin filament? a) single actin strand b) triple helix c) hyperpolar filament d) double helix e) supercoil Answer: d

Difficulty: Easy Learning Objective: LO 9.8 Explain the structure and function of actin and myosin and how they interact.

Section Reference: Section 9.8 Actin and Myosin 65) Which of the following does NOT describe the types of microfilament organization normally seen in cells? a) ordered arrays b) highly branched networks c) tightly anchored bundles d) cylindrical conglomerations e) all of these choices describe types of microfilament organization Answer: d Difficulty: Medium Learning Objective: LO 9.8 Explain the structure and function of actin and myosin and how they interact.

Section Reference: Section 9.8 Actin and Myosin 66) What chemical below is known to bind to free actin monomers and block their incorporation into the polymer? a) cytochalasins b) nocodazole c) phalloidin d) latrunculin e) phalloidin and latrunculin Answer: d Difficulty: Medium Learning Objective: LO 9.8 Explain the structure and function of actin and myosin and how they interact.

Section Reference: Section 9.8 Actin and Myosin 67) What motor is associated with microfilaments? a) myoglobin b) kinesin c) myosin d) dynein

e) myometrium Answer: c Difficulty: Easy Learning Objective: LO 9.8 Explain the structure and function of actin and myosin and how they interact.

Section Reference: Section 9.8 Actin and Myosin 68) The myosin filament is characterized as a(n) _________ filament. a) bipolar b) unipolar c) tripolar d) parallel e) orthogonal Answer: a Difficulty: Easy Learning Objective: LO 9.8 Explain the structure and function of actin and myosin and how they interact.

Section Reference: Section 9.8 Actin and Myosin 69) A culture of Dictyostelium slime mold is prepared in which the myosin II gene is deleted. In which of the activity/ activities described below are these cells unable to participate? a) separation of chromosomes during mitosis b) cell elongation c) cytokinesis d) separation of chromosomes during mitosis and cell elongation e) separation of chromosomes during mitosis and cytokinesis Answer: c Difficulty: Medium Learning Objective: LO 9.8 Explain the structure and function of actin and myosin and how they interact.

Section Reference: Section 9.8 Actin and Myosin 70) Why is myosin V able to take very large steps along a microfilament? a) Its neck is twisted. b) Its neck is relatively long.

c) Its neck is relatively short. d) Its tail is very long. e) Its tail is bipolar.

Answer: b Difficulty: Easy Learning Objective: LO 9.8 Explain the structure and function of actin and myosin and how they interact.

Section Reference: Section 9.8 Actin and Myosin 71) Along which structure do membranous vesicles and organelles typically engage in local movement in the cell periphery of an animal cell? a) mitochondria b) microtubules c) actin filaments d) intermediate filaments e) lysosomes Answer: c Difficulty: Medium Learning Objective: LO 9.8 Explain the structure and function of actin and myosin and how they interact.

Section Reference: Section 9.8 Actin and Myosin 72) How do muscle cells become multinucleate? a) They become multinucleate as they undergo fission. b) They become multinucleate via the embryonic fusion of large numbers of mononucleate myoblasts. c) They become multinucleate via the embryonic fusion of large numbers of multinucleate myoblasts. d) They become multinucleate via mitosis in myoblasts without cytokinesis. e) They become multinucleate via the embryonic fusion of mononucleaateneuroblasts.

Answer: b Difficulty: Medium Learning Objective: LO 9.9Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction

73) Myofibrils in a muscle cell are made up of a repeating linear array of contractile units called ________. a) sarcocytes b) blastomeres c) myomeres d) sarcomeres e) myotubules Answer: d Difficulty: Easy Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction 74) What is the name of the lightly staining areas at the outer edges of a sarcomere? a) A bands b) H zones c) I bands d) Z lines e) M lines Answer: c Difficulty: Easy Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction 75) What is the name of the densely staining area between the lightly staining areas at the outer edges of a sarcomere? a) A bands b) H zones c) I bands d) Z lines e) M lines Answer: a

Difficulty: Easy Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction 76) Which region of the sarcomere contains only actin thin filaments or actin filaments? a) A bands b) H zones c) I bands d) Z lines e) M lines Answer: c Difficulty: Medium Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction 77) Which region of the sarcomere represents the region of overlap between the two types of filaments in the sarcomere? a) A bands b) the part of the A band on either side of the H zone c) I bands d) Z lines e) the part of the H zone on either side of the A band Answer: b Difficulty: Medium Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction 78) What accounts for the decrease in the length of an entire muscle? a) the combined decrease in sarcomere length b) the combined shortening of actin filaments c) the combined shortening myosin filaments d) the combined shortening of thin filaments e) the combined decrease in sarcomere length and the combined shortening of actin filaments

Answer: a Difficulty: Medium Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction 79) What happens to the Z line positioning after contraction of the sarcomere? a) The distance between the Z lines does not change. b) The distance between the Z lines decreases. c) The distance between the Z lines increases. d) The Z lines disappear. e) The Z lines become curved.

Answer: b Difficulty: Medium Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction 80) What protein is thought to act like a "molecular ruler" by regulating the number of actin monomers that are allowed to assemble into a thin filament? a) troponin b) myosin c) nebulin d) titin e) tropomyosin Answer: c Difficulty: Easy Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction 81) What is the name of the largest protein yet discovered? It extends from the M line in the center of the sarcomere along the myosin filament and past the A band to terminate at the Z line. a) troponin

b) myosin c) actinin d) titin e) tropomyosin Answer: d Difficulty: Easy Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction 82) How does an actin thin filament manage to move continuously during a contraction cycle? a) All of the myosin heads beat synchronously. b) All of the myosin heads beat out of synchrony with one another. c) They use an enormous amount of ATP. d) They use an enormous amount of GTP. e) none of these choices Answer: b Difficulty: Medium Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction

83) What provides the energy that drives sarcomere contraction? a) ATP b) ADP c) GTP d) GDP e) none of these choices Answer: a Difficulty: Medium Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction

84) The point at which the neuron axon terminus and the muscle fiber make contact is called the _________. a) neuromuscular terminus b) nerve exons c) neural conjunctions d) neuromuscular junction e) neuromuscular conjunction Answer: d Difficulty: Medium Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction 85) What blocks the myosin-binding sites on actin thin filaments in a stimulated sarcomere? a) troponin b) myosin itself c) tropomyosin d) titin e) nothing Answer: e Difficulty: Medium Learning Objective: LO 9.9 Describe the molecular components of muscle and how they interact in contraction.

Section Reference: Section 9.9 Muscle Organization and Contraction 86) Muscle contracted to a size shorter than its resting length has less tension than one at resting length because: a) Z discs will collide with thin filaments b) Z discs will collide with thick filaments c) H bands will widen d) A bands will widen e) none of these is a correct explanation for the reduced tension Answer: b Difficulty: Medium Learning Objective: LO 9.10 Explain the molecular basis and clinical implications of muscle

biomechanics Section Reference: Section 9.10 Engineering Linkage: Muscle Biomechanics 87) Techniques for measuring muscle activity include all of the following EXCEPT: a) placing electrodes on the skin surface close to muscles b) placing electrodes into muscle by piercing the skin c) detecting vibrations produced by superficial muscles d) detecting vibrations produced by deep muscles e) all are standard activity-measuring techniques Answer: c Difficulty: Easy Learning Objective: LO 9.10 Explain the molecular basis and clinical implications of muscle biomechanics Section Reference: Section 9.10 Engineering Linkage: Muscle Biomechanics 88) Characteristics of Functional Electrical Stimulation (FES) include: a) using an electrode to stimulate muscle contraction b) application in assisting patients whose nerves have been severed c) application in assisting patients whose nerves have degenerated due to a variety of medical conditions d) muscle fatigue issues due to single electrode stimulus e) all choices are correct Answer: e Difficulty: Medium Learning Objective: LO 9.10 Explain the molecular basis and clinical implications ofmuscle biomechanics Section Reference: Section 9.10Engineering Linkage: Muscle Biomechanics 89) What is a major influence in determining the organization and behavior of actin filaments inside cells? a) axonemes b) tubulin c) actin-binding proteins d) dynein e) actin-binding proteins and dynein

Answer: c Difficulty: Medium Learning Objective: LO 9.11 Describe the function of each category of actin-binding proteins.

Section Reference: Section 9.11Actin-Binding Proteins 90) Proteins that accelerate the polymerization of actin filaments are called ________. a) nucleons b) nucleating proteins c) monomer-sequestering proteins d) end-blocking proteins e) nucleons and nucleating proteins Answer: b Difficulty: Medium Learning Objective: LO 9.11 Describe the function of each category of actin-binding proteins.

Section Reference: Section 9.11 Actin-Binding Proteins 91) ________ proteins share considerable sequence homology with actins and accelerate the polymerization of actin filaments. a) Actin-nucleating b) Actin-racemase c) Actin-related d) Tubulin-related e) Actin-rated Answer: c Difficulty: Easy Learning Objective: LO 9.11 Describe the function of each category of actin-binding proteins.

Section Reference: Section 9.11 Actin-Binding Proteins 92) A shift in the concentration or activity of which type of proteins can cause a shift in the equilibrium between actin monomers and polymers? a) nucleating proteins b) monomer-sequestering proteins c) endolysins d) capping proteins e) all of these choices

Answer: b Difficulty: Medium Learning Objective: LO 9.11 Describe the function of each category of actin-binding proteins.

Section Reference: Section 9.11 Actin-Binding Proteins 93) Which type of actin-binding protein is known to decrease cytoplasmic viscosity by breaking existing actin filaments into two or more pieces? a) monomer-polymerizing proteins b) cross-linking proteins c) filament-severing proteins d) actin-filament depolymerizing proteins e) end-blocking proteins Answer: c Difficulty: Easy Learning Objective: LO 9.11 Describe the function of each category of actin-binding proteins.

Section Reference: Section 9.11 Actin-Binding Proteins 94) Which of the following non-muscle cell activities do NOT involve actin filaments often working in concert with myosin motors? a) cytokinesis b) blood platelet activation c) vesicle trafficking d) red blood cells carrying oxygen e) changes in cell shape Answer: d Difficulty: Medium Learning Objective: LO 9.12 Explain the molecular mechanisms of cellular motility and the molecular basis of changes in cell shape.

Section Reference: Section 9.12 Cellular Motility 95) As a fibroblast moves, its leading edge extends from the cell as a broad, flattened, veil-like protrusion called a ________. a) pseudopodium b) lamella c) lamellipodium

d) podium e) extensor Answer: c Difficulty: Easy Learning Objective: LO 9.12 Explain the molecular mechanisms of cellular motility and the molecular basis of changes in cell shape.

Section Reference: Section 9.12 Cellular Motility 96) If you were to fix a fish keratocyte and stain it with fluorescent antibodies for myosin II, where would you see the myosin II? a) in the advancing lamellipodium edge b) in the rear of the cell c) in a band where the rear of the lamellipodium joins the rest of the cell d) around the nucleus e) surrounding the mitochondria Answer: c Difficulty: Hard Learning Objective: LO 9.12 Explain the molecular mechanisms of cellular motility and the molecular basis of changes in cell shape.

Section Reference: Section 9.12 Cellular Motility 97) The focal complexes that form near the leading edge of a motile cell exert traction force through their associated __________ and then typically disassemble as the cell moves forward or mature into larger, more contractile focal adhesions. a) microtubules b) keratin filaments c) vinculin filaments d) actin filaments e) actinin filaments Answer: d Difficulty: Easy Learning Objective: LO 9.12 Explain the molecular mechanisms of cellular motility and the molecular basis of changes in cell shape.

Section Reference: Section 9.12 Cellular Motility

98)It was found that Listeria infection could NOT be spread from one cell to its neighbors on a petri dish in the presence of cytochalasin. This suggested that ___________. a) actin polymerization is required for Listeria infection b) tubulin polymerization is required for Listeria infection c) cytochalasin is required for Listeria infection d) cytochalasin is toxic e) intermediate filaments are required for Listeria infection Answer: a Difficulty: Hard Learning Objective: LO 9.12 Explain the molecular mechanisms of cellular motility and the molecular basis of changes in cell shape.

Section Reference: Section 9.12 Cellular Motility

99) Using a macrophage-like cell line, researchers infected one set of petri dishes with wild-type Listeria, and, as a negative control, infected another set with a Listeria mutant that was unable to enter cells. At specific time points, the cells were fixed and prepared for electron microscopy. Two hours after infection, they observed that the wild-type Listeria in the cytoplasm were surrounded by ______________. a) a cloud of tubulin b) a cloud of actin c) a cloud of keratin d) a growth cone e) comet tails of actin filaments Answer: b Difficulty: Medium Learning Objective: LO 9.12 Explain the molecular mechanisms of cellular motility and the molecular basis of changes in cell shape.

Section Reference: Section 9.12 Cellular Motility 100) Which of the following traits is NOT seen upon close examination of a living growth cone of an elongating axon? a) a broad, flattened lamellipodium that creeps out over the substratum b) stiff microspikes pointing outward to the edge of the lamellipodium c) many cilia that attach to the substratum and pull the growth cone forward d) highly elongated filopodia that extend and retract continuously e) none of these choices is observed

Answer: c Difficulty: Medium Learning Objective: LO 9.12 Explain the molecular mechanisms of cellular motility and the molecular basis of changes in cell shape.

Section Reference: Section 9.12 Cellular Motility 101) After they have elongated, the cells of the neural epithelium become constricted at one end, causing them to become wedge shaped and leading the entire layer of cells to curve inward.

What causes this constriction? a) contraction of microtubules in the cytoplasm just above the basal cell membrane b) lengthening of microtubules in the cytoplasm just below the apical cell membrane c) contraction of a band of actin filaments that assemble in the cortical region of the cells just above the basal cell membrane d) contraction of a band of actin filaments that assemble in the cortical region of the cells just beneath the apical cell membrane e) shortening of microtubules in the cytoplasm just below the apical cell membrane Answer: d Difficulty: Medium Learning Objective: LO 9.12 Explain the molecular mechanisms of cellular motility and the molecular basis of changes in cell shape.

Section Reference: Section 9.12 Cellular Motility 102) The role of building the cytokinetic ring during cell division in prokaryotes is executed by _________. a) actin b) tubulin c) FtsZ d) ParM e) Crescentin Answer: c Difficulty: Medium Learning Objective: LO 9.13 Describe the functions of each of the components of the bacterial cytoskeleton.

Section Reference: Section 9.13 The Bacterial Cytoskeleton

103) The protein FtsZ acts in the bacterial cell analogously to the ______ cytoskeleton during eukaryotic cytokinesis and is a(n) _________ homolog that is found in nearly all prokaryotic cells. a) actin, actin b) actin, tubulin c) tubulin, actin d) actin, intermediate filament e) tubulin, tubulin Answer: b Difficulty: Medium Learning Objective: LO 9.13 Describe the functions of each of the components of the bacterial cytoskeleton.

Section Reference: Section 9.13 The Bacterial Cytoskeleton 104) The protein ParM has been shown to play a role in plasmid segregation during bacterial cell division analogous to the action of ___________during mitosis and is structurally similar to __________. a) actin filaments, actin b) actin filaments, tubulin c) microtubules, tubulin d) intermediate filaments, keratin e) microtubules, actin Answer: e Difficulty: Medium Learning Objective: LO 9.13 Describe the functions of each of the components of the bacterial cytoskeleton.

Section Reference: Section 9.13 The Bacterial Cytoskeleton 105) The protein Crescentin (CreS) has been implicated in regulating the shape of some bacterial cells and forms bundled filaments that give bacteria containing it a highly curved shape; it resembles __________ in structure. a) actin filaments b) microtubules c) titin d) intermediate filaments e) ParM

Answer: d Difficulty: Medium Learning Objective: LO 9.13 Describe the functions of each of the components of the bacterial cytoskeleton.

Section Reference: Section 9.13 The Bacterial Cytoskeleton 106) The protein _________ has been implicated in regulating the shape of some bacterial cells; it is expressed in rod-shaped and helical bacteria. It resembles __________in structure. a) MreB, tubulin b) MreB, actin c) CreS, tubulin d) CreS, actin e) ParM, keratin Answer: b Difficulty: Medium Learning Objective: LO 9.13 Describe the functions of each of the components of the bacterial cytoskeleton.

Section Reference: Section 9.13 The Bacterial Cytoskeleton 107) The deletion of the mreB gene in Escherichia coli results in __________. a) rod-shaped cells b) crescent-shaped cells c) spherical cells d) spiral cells e) cells that look like bunches of grapes Answer: c Difficulty: Medium Learning Objective: LO 9.13 Describe the functions of each of the components of the bacterial cytoskeleton.

Section Reference: Section 9.13 The Bacterial Cytoskeleton

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 10

Question Type: Multiple Choice

1) Which of the following is NOT a conclusion reached by Mendel? a) Characteristics of plants are governed by distinct factors or units of inheritance. b) Gametes from each plant have two copies of the gene for each trait. c) An organism's two alleles segregate from each other during gamete formation. d) The two alleles for a trait carried by an organism may be identical to one another. e) The two alleles for a trait carried by an organism may be different from one another.

Answer: b Difficulty: Medium Learning Objective: LO 10.1: Relate Mendel's conclusions to the modern concept of genetic inheritance.

Section Reference: Section 10.1 The Concept of a Gene as a Unit of Inheritance

2) Mendel’s Law of Independent Assortment states that ____________. a) segregation of an allelic pair for one trait has no effect on segregation of alleles for another trait b) an organism's two alleles for a gene separate from one another during gamete formation c) segregation of an allelic pair for one trait has a great effect on segregation of alleles for another trait d) an organism's three alleles for a gene separate from one another during gamete formation e) gametes are diploid and highly variable Answer: a Difficulty: Medium Learning Objective: LO 10.1: Relate Mendel's conclusions to the modern concept of genetic inheritance.

Section Reference: Section 10.1 The Concept of a Gene as a Unit of Inheritance

3) When both a dominant and recessive allele for a particular gene are present together in the same plant, _________. a) the recessive allele is always expressed b) the dominant allele is expressed some of the time c) the dominant allele is always expressed d) the dominant allele is masked by the recessive allele Answer: c Difficulty: Medium Learning Objective: LO 10.1: Relate Mendel's conclusions to the modern concept of genetic inheritance.

Section Reference: Section 10.1 The Concept of a Gene as a Unit of Inheritance

4) Different versions of a gene are called _________. a) heterologues b) homologues c) allogues d) alleles e) mutoids Answer: d Difficulty: Easy Learning Objective: LO 10.1: Relate Mendel's conclusions to the modern concept of genetic inheritance.

Section Reference: Section 10.1 The Concept of a Gene as a Unit of Inheritance

5) The effect of _________ on embryonic development is ___________. a) polyandry, disruptive cell divisions and the early death of the embryo b) mitosis, disruptive cell divisions and the early death of the embryo c) polyspermy, disruptive cell divisions and the early death of the embryo d) polyspermy, the embryo develops normally but is twice as large e) polyandry, the embryo develops normally but is twice as large Answer: c Difficulty: Medium

Learning Objective: LO 10.2 Describe the discovery of chromosomes.

Section Reference: Section 10.2 The Discovery of Chromosomes

6) What abnormality is observed in daughter cells from an egg that has been fertilized by more than one sperm? a) They have more cilia. b) They are smaller. c) They have variable numbers of chromosomes. d) They enter meiosis unexpectedly. e) They swell to three times their normal size.

Answer: c Difficulty: Easy Learning Objective: LO 10.2 Describe the discovery of chromosomes.

Section Reference: Section 10.2 The Discovery of Chromosomes

7) What would happen if meiosis did not include a reduction division? a) The number of chromosomes in a species would remain the same with each generation. b) The number of chromosomes in a species would double with each generation. c) The number of chromosomes in a species would halve with each generation. d) The number of chromosomes in a species would quadruple with each generation. e) Chromosomes would shrink prior to each cell division.

Answer: b Difficulty: Easy Learning Objective: LO 10.2 Describe the discovery of chromosomes.

Section Reference: Section 10.2 The Discovery of Chromosomes 8) Who was the first scientist to propose that meiosis included a reduction division? a) Edouard van Beneden b) Theodore Boveri c) Gregor Mendel d) August Weismann e) Walther Flemming Answer: d

Difficulty: Easy Learning Objective: LO 10.2 Describe the discovery of chromosomes.

Section Reference: Section 10.2 The Discovery of Chromosomes

9) How many chromosomes would a sexually-reproducing organism with 6 chromosomes in generation 0 have in generation 4 if there are reduction divisions in meiosis? a) 6 b) 12 c) 24 d) 48 e) 96 Answer: a Difficulty: Hard Learning Objective: LO 10.2 Describe the discovery of chromosomes.

Section Reference: Section 10.2 The Discovery of Chromosomes

10) Which part of the cell behaves in a way corresponding to the behavior of Mendel's genetic factors? a) mitochondria b) endoplasmic reticulum c) homologous pairs of chromosomes d) homologous pairs of centrioles e) nucleolus Answer: c Difficulty: Medium Learning Objective: LO 10.3 Explain the relationship between a chromosome and a linkage group.

Section Reference: Section 10.3 Chromosomes as the Carriers of Genetic Information

11) Which word below refers to a pair of homologous chromosomes? a) chromophores b) bivalent c) birefringence

d) bilateral e) nucleolus Answer: b Difficulty: Easy Learning Objective: LO 10.3 Explain the relationship between a chromosome and a linkage group.

Section Reference: Section 10.3 Chromosomes as the Carriers of Genetic Information

Question Type: Multiple Select

12) Agrobacterium tumefaciens is a gram-negative bacterium found in soil that causes:

a) highly acidic soil. b) transgenic plants. c) Crown gall disease. d) Dutch elm disease.

Answer: c

Difficulty: Easy Learning Objective 1: LO 10.10 Identify the basis of gene transfer in Agrobacterium.

Section Reference: 10.10: Green Cells: Gene Transfer by Agrobacterium tumefaciens

Question Type: Multiple Choice

13) Which term is an accurate description of a linkage group, as it was first described by Sutton? a) a group of genes carried on the same chromosome

b) a pair of alleles carried on the same homologous chromosome pair c) a group of chromosomes found in a gamete d) a group of chromosomes found in a fertilized egg Answer: a Difficulty: Easy Learning Objective: LO 10.3 Explain the relationship between a chromosome and a linkage group.

Section Reference: Section 10.3 Chromosomes as the Carriers of Genetic Information

14) Which of the following characteristics initially made fruit flies a poor subject for genetic studies? a) a short generation time from egg to maturity b) they produced up to 1000 eggs in a lifetime c) easy to house and breed d) there was only one strain of flies available e) inexpensive to maintain Answer: d Difficulty: Easy Learning Objective: LO 10.3 Explain the relationship between a chromosome and a linkage group.

Section Reference: Section 10.3 Chromosomes as the Carriers of Genetic Information

15) What was the original strain of fruit flies called in Morgan’s studies? a) wild ones b) originals c) wild type d) normal type e) dominant type Answer: c Difficulty: Medium Learning Objective: LO 10.3 Explain the relationship between a chromosome and a linkage group.

Section Reference: Section 10.3 Chromosomes as the Carriers of Genetic Information

16) What appears to be the reason for the production of the large Drosophila larvae salivary gland cells? a) to allow less gene expression b) to maintain low level gene expression c) to maintain high secretory activity d) to allow the cells to take up more space e) to digest larger amounts of phagocytic material Answer: c Difficulty: Easy Learning Objective: LO 10.3 Explain the relationship between a chromosome and a linkage group.

Section Reference: Section 10.3 Chromosomes as the Carriers of Genetic Information

17) What is the name of chromosomes that have as many as 1024 times the number of DNA strands usually present? a) polymorphic chromosomes b) polytene chromosomes c) homologous chromosomes d) heterozygous chromosomes e) papillosomes Answer: b Difficulty: Easy Learning Objective: LO 10.3 Explain the relationship between a chromosome and a linkage group.

Section Reference: Section 10.3 Chromosomes as the Carriers of Genetic Information

18) The individual banding patterns on Drosophila chromosomes provided evidence for the validity of what phenomenon? a) mitosis b) meiosis c) gene mapping d) translation e) respiration

Answer: c Difficulty: Medium Learning Objective: LO 10.3 Explain the relationship between a chromosome and a linkage group.

Section Reference: Section 10.3 Chromosomes as the Carriers of Genetic Information

19) The building blocks of a nucleotide are ___________. a) a pentose sugar and a phosphate group b) a pentose sugar and a nitrogenous base c) a phosphate group and a nitrogenous base d) a pentose sugar, a phosphate group and a nitrogenous base e) a pentose sugar, a phosphate group and an amino acid Answer: d Difficulty: Medium Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

20) The nitrogenous base attaches to the ____-carbon of the nucleotide's sugar. a) 1' b) 2' c) 3' d) 4' e) 5' Answer: a Difficulty: Easy Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

21) Which of the following is a DNA nucleotide? a) a phosphate group, adenine and ribose b) a phosphate group, guanine and deoxyribose

c) cytosine and ribose d) thymine and deoxyribose e) a phosphate group and adenine Answer: b Difficulty: Medium Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

22) Which of the following is an RNA nucleoside? a) a phosphate group, adenine and ribose b) a phosphate group, guanine and deoxyribose c) cytosine and ribose d) thymine and ribose e) a phosphate group and adenine Answer: c Difficulty: Medium Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

23) The backbone of a DNA molecule is _________. a) made up of sugars alone b) made up of nitrogenous bases alone c) made up of phosphate groups alone d) made up of alternating phosphate and sugar groups e) made up of alternating sugars and nitrogenous bases Answer: d Difficulty: Medium Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

24) Purines are characterized by _______; pyrimidines are characterized by ______.

a) two rings, one ring b) one ring, two rings c) two rings, three rings d) two rings, two rings e) two rings, one chain Answer: a Difficulty: Medium Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

25) The bonds that hold DNA and RNA backbones together are known as __________. a) 3'-4'-phosphodiester linkages b) 3'-5'-phosphodiester linkages c) phosphate ethers d) 1,4-glycosidic linkages e) peptide bonds Answer: b Difficulty: Easy Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

26) The ends of a polynucleotide chain are the ____ end and the ____ end. a) 5', N-terminal b) 3', 4' c) 3', 5' d) N-terminal, C-terminal e) 3', C-terminal Answer: c Difficulty: Easy Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

27) The original model of DNA structure stated that each unit in DNA contained all four nitrogenous bases in a repeating pattern; it was called the ________. a) Endosymbiotic Theory b) Induced Fit Model c) Lock and Key Model d) Tetranucleotide Theory e) Evolutionary Theory Answer: d Difficulty: Easy Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

28) Why is the AMY1 gene more prevalent in humans than in chimpanzees and more prevalent in some human populations than others? (Select all correct choices) a) Chimps have to digest forms of starch different from those digested by humans. b) Chimps have less starch in their diets than humans and therefore need lower levels of amylase. c) Some human populations have more starch in their diets than others. d) The AMY1 gene is directly involved with the ability to speak.

Answer: b, c Difficulty: Medium Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

29) You isolate DNA from a particular organism and analyze it. The amount of adenine was 6 µmoles and the A+T/G+C ratio is 4.0. How much guanine should be in the sample? a) 6 µmoles b) 3 µmoles c) 1.5 µmoles d) 4 µmoles e) 12 µmoles Answer: c Difficulty: Hard

Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

30) What technique supplied the data that led Watson and Crick to hypothesize the double helical structure of DNA? a) sucrose density centrifugation b) polyacrylamide gel electrophoresis c) X-ray diffraction/crystallography d) autoradiography e) ion exchange chromatography Answer: c Difficulty: Easy Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

31) In a right-handed double helix, if one looks down the central axis of the molecule, _________. a) each strand follows a counterclockwise path as it moves away from the observer b) each strand follows a clockwise path as it moves away from the observer c) each strand follows a rectangular path as it moves toward the observer d) each strand follows a clockwise path as it moves toward the observer e) one strand follows a clockwise path as it moves away from the observer, the other follows a clockwise path as it moves toward the observe Answer: b Difficulty: Medium Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

32) Which molecule provides a DNA molecule with most of its negative charge? a) deoxyribose b) ribose c) phosphate group d) chlorine ion

e) adenine Answer: c Difficulty: Easy Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

33) Which statement below explains the uniform width of the DNA molecule along its entire width? a) A purine nitrogenous base always pairs with another purine nitrogenous base. b) A pyrimidine nitrogenous base always pairs with another pyrimidine nitrogenous base. c) A pyrimidine nitrogenous base always pairs with a purine nitrogenous base. d) Repulsion between phosphate groups keeps the strands a uniform distance apart. e) Attraction between phosphate groups keeps the strands a uniform distance apart.

Answer: c Difficulty: Medium Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

34) ________ refers to the fact that the sequence of one DNA strand specifies the sequence of the other strand in the double helix. a) Indirectionality b) Complexity c) Complementarity d) Similarity e) Compulsivity Answer: c Difficulty: Easy Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

35) The inheritable information encoded in DNA resides in ________.

a) phosphates in the backbone b) sugars in the backbone c) the DNA base sequence d) the sugars and phosphate groups together e) the phosphodiester linkages Answer: c Difficulty: Easy Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

36) Which type of enzyme is essential for processes like DNA replication and transcription to prevent excessive supercoiling from developing as the complementary strands of the DNA duplex separate and unwind? a) topoisomerase b) telomerase c) topologicase d) helicase e) isomerase Answer: a Difficulty: Easy Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

37) Which type of enzyme makes a transient break in both DNA duplex strands and then transports another segment of a DNA molecule (or separate molecule entirely) through the break and reseals the severed strands? a) Type I topoisomerase b) Type II topoisomerase c) Type I topologicase d) Type II topologicase e) Type I isomerase Answer: b Difficulty: Easy Learning Objective: LO 10.4 Describe the structure and basic composition of DNA.

Section Reference: Section 10.4 The Chemical Nature of the Gene

38) What function does topoisomerase II serve in preparation for mitosis? a) It pulls the chromosomes apart in association with the spindle. b) It organizes the spindle. c) It disentangles DNA molecules. d) It moves genes from place to place. e) It lengthens chromosomes at the end of mitosis.

Answer: c Difficulty: Medium Learning Objective: LO 10.4 Describe the structure and basic composition of DNA. Section Reference: Section 10.4 The Chemical Nature of the Gene

39) In humans, the genome is essentially equivalent to all of the genetic information that is present in a ______ set of chromosomes. a) triploid b) double c) haploid d) diploid e) polyploid Answer: c Difficulty: Easy Learning Objective: LO 10.5 Explain how DNA denaturation and renaturation have helped advance the understanding of genome structure.

Section Reference: Section 10.5 The Complexity of the Genome

40) How is the degree of DNA denaturation measured in C0t studies? a) Absorbance of UV light by DNA increases as DNA denatures. b) Absorbance of UV light by DNA decreases as DNA denatures. c) Absorbance of infrared light by DNA increases as DNA denatures. d) The temperature of the solution indicates the degree of denaturation. e) The color of the solution indicates the degree of denaturation.

Answer: a Difficulty: Medium Learning Objective: LO 10.5 Explain how DNA denaturation and renaturation have helped advance the understanding of genome structure.

Section Reference: Section 10.5 The Complexity of the Genome

41) Which type of DNA sequence is typified by short sequences of DNA (five to a few hundred base pairs in length) repeated a large number of times in tandem to form very large clusters, each containing up to several million base pairs of DNA? a) satellite DNAs b) minisatellite DNAs c) microsatellite DNAs d) consensus sequences e) microminisatellite DNAs Answer: a Difficulty: Easy Learning Objective: LO 10.5 Explain how DNA denaturation and renaturation have helped advance the understanding of genome structure.

Section Reference: Section 10.5 The Complexity of the Genome

42) Why are satellite DNAs separated from the bulk of the genome during density gradient centrifugation? a) They include more phosphate and sugar groups per nitrogenous base. b) Their base composition is significantly different from that of the bulk of the genome. c) They have higher molecular weights. d) They have a higher negative charge than the bulk of the genome. e) They have a higher positive charge than the bulk of the genome.

Answer: b Difficulty: Medium Learning Objective: LO 10.5 Explain how DNA denaturation and renaturation have helped advance the understanding of genome structure.

Section Reference: Section 10.5 The Complexity of the Genome

43) Why are satellite DNAs called satellite DNAs? a) They orbit the Earth. b) They form bands in a density gradient within the main band formed by the bulk of the genome. c) They form bands in a density gradient separate from the main band formed by the bulk of the genome. d) They form bands on an agarose gel separate from the main band formed by the bulk of the genome. e) They form small bands on an agarose gel within the main band formed by the bulk of the genome.

Answer: c Difficulty: Medium Learning Objective: LO 10.5 Explain how DNA denaturation and renaturation have helped advance the understanding of genome structure.

Section Reference: Section 10.5 The Complexity of the Genome

44) Why would much larger satellite DNAs be unlikely to form satellites in density gradients? a) Larger satellites are less likely to have a base composition similar to that of the bulk of the genome. b) Larger satellites have higher molecular weights than the bulk of the genome. c) Larger satellites will have the same molecular weight as the bulk of the genome. d) Larger satellites are more likely to have a base composition similar to that of the bulk of the genome. e) Larger satellites have the same charge as the bulk of the genome.

Answer: d Difficulty: Hard Learning Objective: LO 10.5 Explain how DNA denaturation and renaturation have helped advance the understanding of genome structure.

Section Reference: Section 10.5 The Complexity of the Genome

45) The labeled, single-stranded DNAs used to localize the positions of specific complementary DNA sequences within the chromosomes in in situ hybridization studies are called _______. a) altoids b) probatives c) probes

d) bindins e) prorbs Answer: c Difficulty: Easy Learning Objective: LO 10.5 Explain how DNA denaturation and renaturation have helped advance the understanding of genome structure.

Section Reference: Section 10.5 The Complexity of the Genome

46) To what does avidin directly bind with high affinity? a) RNA b) DNA c) fish d) biotin e) centromeres Answer: d Difficulty: Medium Learning Objective: LO 10.5 Explain how DNA denaturation and renaturation have helped advance the understanding of genome structure.

Section Reference: Section 10.5 The Complexity of the Genome

47) Satellite DNAs have been localized to the _________________- during in situ hybridization studies: a) nucleolus b) centromere c) spindle d) mitochondria e) nucleosomes Answer: b Difficulty: Easy Learning Objective: LO 10.5 Explain how DNA denaturation and renaturation have helped advance the understanding of genome structure.

Section Reference: Section 10.5 The Complexity of the Genome

48) What kind of DNA sequence is 20% to 80% of the total DNA in plant and animal genomes, depending on the organism, and includes sequences repeated within the genome a few times to tens of thousands of times? a) moderately repeated DNA sequences b) nonrepeated sequences c) highly repeated sequences d) satellites, minisatellites and microsatellites e) very unique sequence DNA Answer: a Difficulty: Easy Learning Objective: LO 10.5 Explain how DNA denaturation and renaturation have helped advance the understanding of genome structure.

Section Reference: Section 10.5 The Complexity of the Genome

49) What is one proposed explanation for the wide discrepancies in genome sizes from species to species? a) More advanced organisms have more DNA. b) Genomes have an extremely variable number of repeated DNA sequences that do not code for proteins. c) Some organisms have multiple repeats of each gene. d) More advanced organisms have more genes. e) More advanced organisms have more centromeric DNA. Answer: b Difficulty: Hard Learning Objective: LO 10.5 Explain how DNA denaturation and renaturation have helped advance the understanding of genome structure.

Section Reference: Section 10.5 The Complexity of the Genome

50) Approximately what percentage of the human genome codes for amino acids in proteins? a) 15% b) 23% c) 1.5% d) 7.5% e) 70%

Answer: c Difficulty: Easy Learning Objective: LO 10.5 Explain how DNA denaturation and renaturation have helped advance the understanding of genome structure.

Section Reference: Section 10.5 The Complexity of the Genome

51) Which polyploidization mechanism is thought to occur most often in plants? a) Two related species mate, forming an organism with the combined chromosomes from both parents. b) A single-celled embryo duplicates its chromosomes, but they are not separated into separate cells and remain in a single cell that develops into a viable embryo. c) Chromosomes spontaneously split down the middle during the G1 portion of the cell cycle. d) Plants form a syncytium. e) There is a spontaneous duplication of chromosomes at random.

Answer: a Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

52) Susumu Ohno proposed that the evolution of vertebrates from a much simpler invertebrate ancestor was made possible by two separate rounds of whole-genome duplication during an early evolutionary period. How was it proposed that the whole-gene duplication led to the encoding of the more complex vertebrate body? a) The extra genes immediately resulted in a bigger body. b) The many extra genes generated by genetic duplication can be molded over time into new genes needed to encode the complex vertebrate body. c) The genes could rapidly combine to make new structures. d) The gene duplication makes the nucleus bigger and makes the cell more versatile. e) The duplication of the chromosomes leads to new cytoplasmic structures in the first generation.

Answer: b Difficulty: Medium

Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

53) What evidence supports the Ohno suggestion about vertebrate evolution from ancestral invertebrates by whole-genome duplication? a) Modern vertebrates have four times the number of certain groups of genes compared to their homologues in amphioxus. b) Modern vertebrates and amphioxus have exactly the same number of certain groups of genes. c) Modern vertebrates have six times the number of certain groups of genes compared to their homologues in amphioxus. d) Amphioxus has four times the number of certain groups of genes compared to their homologues in modern vertebrates. e) Amphioxus has eight times the number of certain groups of genes compared to their homologues in modern vertebrates.

Answer: a Difficulty: Hard Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

54) In which of the following organisms is polyploidization common? a) apples b) wheat c) bananas d) coffee e) all of these are examples of polyploidization Answer: e Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

55) What causes unequal crossing over?

a) A pair of homologous chromosomes align perfectly during meiosis followed by genetic exchange. b) A pair of homologous chromosomes aligns imperfectly during meiosis followed by genetic exchange. c) Sections of the chromosome are replicated spontaneously. d) Pieces of chromosomes are translocated from one place to another.

Answer: b Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

56) How is a cluster of tandemly repeated segments generated at a localized site within a chromosome? a) by a single duplication event b) by multiple vaporizations c) by repeated duplication of a particular sequence over a number of generations d) by a single inversion event e) by a single deletion even Answer: c Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

57) When a gene is duplicated one or more times, it gives rise to a group of genes that may diverge by mutation, but their sequences will generally remain closely related and they will encode similar polypeptides. The genes produced in this way can be referred to as ________. a) isotopes b) isomers c) isosceles d) gene families e) gene isoforms Answer: d

Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

58) Which phrase below describes the structure of hemoglobin? a) either an a-globin or a b-globin chain b) an a-globin and a b-globin chain c) two a-globin and two b-globin chains d) three a-globin chains and one b-globin chain e) four a-globin or four b-globin chains Answer: c Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

59) Hemoglobin molecules analyzed at various times during an animal's life seem to be highly variable. What is the explanation for this? a) Contaminants at various points in an organism's life cause the variation in data. b) Hemoglobin denatures when isolated from older embryos. c) The combinations of a-family and b-family globin polypeptides differ with developmental stage. d) Hemoglobins are chemically altered as they age. e) Hemoglobins bind copper ions instead of iron ions.

Answer: c Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

60) When a gene has been duplicated one or more times, what are the possible things that can happen to the duplicated gene?

a) The duplicated gene can accumulate favorable mutations and acquire a new function. b) The duplicated gene can be lost through deletion. c) The duplicated gene can be rendered nonfunctional by unfavorable mutations. d) If there are two copies of the gene, both could undergo mutation so that each evolves a more specialized function than the original gene. e) All of these are correct.

Answer: e Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

61) Why is it thought that certain primitive fish diverged from vertebrates before the globin gene was first duplicated? a) The fish are very old. b) The fish do not have any hemoglobin. c) The hemoglobin of the fish consists of 8 polypeptide subunits. d) These fish have only one globin gene instead of multiple globin genes, suggesting that they diverged from other vertebrates before the first duplication of the globin gene. e) These fish have four globin genes instead of a single globin gene, suggesting they diverged from other vertebrates before the first duplication of the globin gene.

Answer: d Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

62) The globin gene cluster contains stretches of DNA that are homologous to the sequences of functional globin genes, but contain severe accumulated mutations that render them nonfunctional. Most of these noncoding regions have no known function. They are considered to be evolutionary relics and are called _________. a) reliquaries b) pseudoemissaries c) pseudogenes d) pseudoproteins

e) pseudoglobins Answer: c Difficulty: Easy Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

63) The genetic rearrangement that Barbara McClintock discovered is called _________ and the mobile genetic elements she discovered are called ________. a) transposition, transposable elements b) transposable elements, transposition c) transference, transferable elements d) mutations, mutable elements e) transposition, transposables Answer: a Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

64) DNA sequences in bacteria that move from one place in the genome to another are called ________. a) movers b) jumpons c) transposons d) transpodons e) jumposons Answer: c Difficulty: Easy Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

65) Transposase is an enzyme that __________. a) degrades transposons b) builds transposons c) catalyzes transposon excision from a donor DNA site and its subsequent insertion at a target DNA site d) degrades target DNA e) rearranges transposon DNA Answer: c Difficulty: Easy Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

66) Which type of DNA sequence in the genome is interspersed and probably arose by transposition of mobile genetic elements? a) satellite DNA b) microsatellite DNA c) minisatellite DNA d) moderately repeated DNA sequences e) unique sequence DNA Answer: d Difficulty: Easy Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

67) How do Alu sequences contribute to the genetic diversity in the human population? a) Their transposition generates considerable differences in the timing of Alu sequence movement. b) Alu sequences amplify the effects of genes that they abut. c) Their transposition generates considerable differences in the location of Alu sequences. d) Alu sequences change the DNA sequences of the genes that they abut. e) Alu sequences reshuffle genes on every chromosome.

Answer: c Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

68) What do many people believe the function of transposable elements is? a) It is thought that they are mostly junk with no function. b) It is thought that they transpose base pairs. c) It is thought that they make enzymes more efficient. d) It is thought that they make enzymes less efficient. e) It is thought that they denature enzymes.

Answer: a Difficulty: Easy Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

69) What word below most accurately describes transposable elements? a) stable b) offspring c) helpers d) genetic scrap yard e) genetic symbionts Answer: d Difficulty: Easy Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

70) A transposable element is a type of genetic parasite that can invade a host genome from the outside world, spread within the genome and be transmitted to offspring. Under what circumstances would a transposable element NOT be able to accomplish this?

a) if there are serious adverse effects on the ability of the host to survive and reproduce b) if there are substantial positive effects on the ability of the host to survive and reproduce c) if it speeds up the activity of amylase d) if is slows down the activity of triosephosphate isomerase e) if it increases the rate at which an organism can sense time Answer: a Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

71) What may be the primary mechanism in the evolution of proteins that are composed of domains derived from different ancestral genes? a) gene duplication b) transposable elements c) crossing over d) random assortment e) genetic hyperbole Answer: b Difficulty: Easy Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

72) _______ is thought to be derived from a reverse transcriptase encoded by an ancient retrotransposon. a) Phosphatase b) Esterase c) Telomerase d) Protein kinase e) Phosphodiesterase Answer: c Difficulty: Medium

Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

73) ________ plays a key role in replicating DNA at the ends of chromosomes. a) PolyA polymerase b) DNA polymerase c) Telomerase d) Protein kinase e) Phosphodiesterase Answer: c Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

74) How might a transposase be responsible for our ability to ward off infectious disease? a) Enzymes that make the proteins in antibodies also make transposases. b) Enzymes involved in antibody gene rearrangement may be derived from a transposase encoded by an ancient DNA transposon. c) Antibodies are transposases. d) Most transposases are antibodies. e) Enzymes involved in transposase gene rearrangement may be derived from ancient antibodies.

Answer: b Difficulty: Medium Learning Objective: LO 10.6 Outline the mechanisms by which genetic elements move from one genome site to another.

Section Reference: Section 10.6 The Stability of the Genome

75) Conserved portions of mammalian genomes are assumed to be _________. a) repeated b) important c) unimportant

d) long e) extraordinary Answer: b Difficulty: Easy Learning Objective: LO 10.7 Identify the mechanisms that can explain how relatively few genes can direct a highly complex organism.

Section Reference: Section 10.7 Sequencing Genomes: The Footprints of Biological Evolution

76) Current estimates place the number of protein-coding human genes in the neighborhood of _______. a) 100,000 b) 30,000 c) 20,000 d) 75,000 e) 5,000 Answer: c Difficulty: Medium Learning Objective: LO 10.7 Identify the mechanisms that can explain how relatively few genes can direct a highly complex organism.

Section Reference: Section 10.7 Sequencing Genomes: The Footprints of Biological Evolution

77) Humans have roughly the same number of protein-coding genes as _________. a) a mouse b) a nematode c) a puffer fish d) a chicken e) all of these are correct Answer: e Difficulty: Easy Learning Objective: LO 10.7 Identify the mechanisms that can explain how relatively few genes can direct a highly complex organism.

Section Reference: Section 10.7 Sequencing Genomes: The Footprints of Biological Evolution

78) A single gene can encode a number of related proteins as a result of a process called _______. a) alternative splicing b) gene expression c) polymorphism d) alternative addition e) alternative expression Answer: a Difficulty: Easy Learning Objective: LO 10.7 Identify the mechanisms that can explain how relatively few genes can direct a highly complex organism.

Section Reference: Section 10.7 Sequencing Genomes: The Footprints of Biological Evolution

79) An area of biological study that focuses on the ways that proteins work together as complex networks rather than as individual actors is called __________. a) systems biology b) complex biology c) systematics d) complexity e) networkonics Answer: a Difficulty: Easy Learning Objective: LO 10.7 Identify the mechanisms that can explain how relatively few genes can direct a highly complex organism.

Section Reference: Section 10.7 Sequencing Genomes: The Footprints of Biological Evolution

80) Experimentation at the J. Craig Venter Institute has led to all of the following EXCEPT: a) inserting a synthetic genome into Mycoplasma b) inserting a synthetic genome into Mycobacterium c) attempts to create minimal bacterial genome through rational gene selection d) attempts to create minimal bacterial genome through mutagenesis Answer: b

Difficulty: Medium Learning Objective: LO 10.8 Explain how DNA-editing technologies make it possible to introduce changes in the genome.

Section Reference: Section 10.8 Engineering Linkage: Engineering Genomes

81) CRISPR-Cas9 gene editing is characterized by: a) introduction of random sequence changes into the human genome b) introduction of large scale genetic changes in diverse genomes c) introduction of non-targeted genetic changes in diverse genomes d) small scale, targeted changes in diverse genomes Answer: d Difficulty: Easy Learning Objective: LO 10.8 Explain how DNA-editing technologies make it possible to introduce changes in the genome.

Section Reference: Section 10.8 Engineering Linkage: Engineering Genomes

82) Venter’s first synthetic genome was comprised of _____________ 1kB segments joined together. a) 11 b) 100 c) 1,000 d) 15,000 Answer: c Difficulty: Easy Learning Objective: LO 10.8 Explain how DNA-editing technologies make it possible to introduce changes in the genome.

Section Reference: Section 10.8 Engineering Linkage: Engineering Genomes

83) When we compare the DNA of the human and chimpanzee, it is seen that the genomes differ by about __________ percent. a) 0.1 b) 0.4 c) 1

d) 4 e) 10 Answer: d Difficulty: Easy Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

84) Which of the following does NOT suggest that the AMY1 gene has been subject to natural selection during human evolution? a) Chimps have one copy of the gene in their genome, while humans have multiple copies of the same gene. b) Chimps have multiple copies of the gene in their genome, while humans have one copy of the same gene. c) There is a higher concentration of the enzyme in human saliva than in chimp saliva. d) The number of copies of the AMY1 gene tends to be higher in human populations that ingest greater quantities of starch in their diet.

Answer: b Difficulty: Medium Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

85) A significant proportion of functional DNA sequences are __________ and thus are _______ parts of the genome. a) duplicated, highly conserved b) constantly evolving, not highly conserved c) constantly evolving, highly conserved d) invariant, not highly conserved e) duplicated, invariant Answer: b Difficulty: Medium Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

86) What does it likely mean if portions of the noncoding regions of the genome are conserved? a) Exons code for proteins. b) Exons are not as important as once was thought. c) Noncoding parts of the genome actually have important, unidentified functions. d) Introns have no importance. e) Introns must be excised to maintain consistency.

Answer: c Difficulty: Easy Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

87) Why would changes in the genes for transcription factors be expected to generate major phenotypic differences? a) They are very highly expressed genes. b) They can affect the expression of large numbers of other genes. c) They can affect the expression of relatively few other genes. d) Their gene products normally denature more rapidly than other gene products. e) Their gene products are remarkably stable.

Answer: b Difficulty: Medium Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

88) Persons with mutations in the FOXP2 gene suffer from a severe speech and language disorder. What is the nature of the disorder? a) The person’s lips are malformed. b) The person is unable to perform the fine muscular movements of lips and tongue that are required for vocal communication. c) The person has malformed vocal cords.

d) The person has a malformed tongue. e) The person with the disorder is deaf.

Answer: b Difficulty: Easy Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

89) ____________ are sites in the genome that vary among different individuals. This term usually refers to a genetic variant that occurs in at least 1% of a species population. a) Genetic variances b) Genetic anomalies c) Genetic polymorphisms d) Genetic polyploidisms e) Genetic polydactyly Answer: c Difficulty: Easy Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

90) The most common type of genetic variability in humans occurs at sites in the genome where single nucleotide differences are found among different members of the population. Which term is NOT a correct reference to these sequence regions? a) single nucleotide polymorphisms b) SNPs c) "snips" d) single nucleotide polymathisms Answer: d Difficulty: Easy Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

91) Using genome-wide association studies (GWASs), an association was found between ___________ and the high risk allele identified as _____________. a) diabetes, APOE4 b) cardiovascular disease, APOE6 c) congestive heart failure, APLE2 d) Alzheimer’s disease, APOE4 Answer: d Difficulty: Easy Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

92) Genome-wide association studies (GWASs) have allowed researchers to identify genes or non-coding sites for which certain variants lead to increased risk of _______________. a) Type 1 diabetes b) Type 2 diabetes c) Crohn’s disease d) cancer e) all choices are correct Answer: e Difficulty: Easy Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

93) Which type of gene or DNA sequence would you predict to contribute most significantly to the phenomenon of epistasis? a) a gene encoding a single enzyme b) a gene encoding a neurotransmitter c) a gene encoding a transcription factor d) a noncoding SNP region Answer: c

Difficulty: Hard Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

94) A large chunk of DNA (around 20 kB) which is likely to be vertically inherited as a block is termed a ______________: a) diplotype b) haplotype c) genotype d) SNP Answer: b Difficulty: Easy Learning Objective: LO 10.9 Describe how comparisons of DNA sequences have been used to explain human evolution.

Section Reference: Section 10.9 The Genetic Basis of “Being Human”

95) In the 1980s, researchers found that the manipulation of Agrobacterium tumor-inducing genes had broader value in

a) genetic modification of economically important crops to improve quality and yield. b) eradicating weeds that are harmful to desirable crop growth. c) identification of cancer causing genes in humans. d) All of the answers are correct.

Answer: a

Difficulty: Easy Learning Objective 1: LO 10.10 Identify the basis of gene transfer in Agrobacterium.

Section Reference: 10.10: Green Cells: Gene Transfer by Agrobacterium tumefaciens

Question Type: Multiple Select

96) Which model organisms provided valuable data in early studies of chromosomal inheritance?

(Select all correct choices) a) humans b) sea urchins c) laboratory mice d) roundworms such as Ascaris Answer: b, d Difficulty: Easy Learning Objective: LO 10.2 Describe the discovery of chromosomes.

Section Reference: Section 10.2 The Discovery of Chromosomes

Question Type: Multiple Select

97) Which of the following can lead to an increase or decrease in the number of chromosomes over time and can thus provide a clear visual footprint of the evolutionary process? (Select all correct choices) a) a simple loss of chromosomes during a mitotic event b) complete fragmentation of a chromosome c) the splitting of a chromosome d) the fusion of two chromosomes into one chromosome Answer: c, d Difficulty: Medium Learning Objective: LO 10.7 Identify the mechanisms that can explain how relatively few genes can direct a highly complex organism.

Section Reference: Section 10.7 Sequencing Genomes: The Footprints of Biological Evolution

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 11

Question Type: Multiple Choice

1) Who was the first to report that certain rare inherited diseases were caused by the absence of specific enzymes? a) Charles Darwin b) Archibald Garrod c) George Beadle d) Vernon Ingram e) James Watson Answer: b Difficulty: Easy Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

2) Alcaptonuria is a genetic disease that is characterized by _________. a) urine turning dark upon exposure to the air b) mental retardation c) paralysis d) urine smelling and tasting like maple syrup e) high fevers Answer: a Difficulty: Easy Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

3) An alcaptonuric lacks the enzyme that oxidizes which metabolite?

a) phenylalanine b) tyrosine c) homogentisic acid d) asparagine e) pantothenic acid Answer: c Difficulty: Easy Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

4) What did Archibald Garrod call diseases like alcaptonuria? a) deadly diseases b) inborn errors of transcription c) homogentisms d) errors e) inborn errors of metabolism Answer: e Difficulty: Easy Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

5) What did Beadle and Tatum use to generate mutations in their experimental organism? a) mustard gas b) irradiation with ultraviolet light c) fluorescent dyes d) ethidium bromide e) Coomassie blue Answer: b Difficulty: Easy Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

6) Beadle and Tatum's research suggested that __________. a) a gene carries the information to build lipids b) a gene carries the information to build carbohydrates c) a gene carries the information for the construction of a particular enzyme d) a gene is made of RNA e) a gene is made of DNA Answer: c Difficulty: Medium Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

7) What was the new name of Beadle and Tatum's hypothesis after it was discovered that some enzymes were composed of more than one polypeptide chain? a) the one gene–one enzyme hypothesis b) the one gene–one polypeptide hypothesis c) the one polypeptide–one enzyme hypothesis d) the one polypeptide–one gene hypothesis e) the one gene–two gene hypothesis Answer: b Difficulty: Easy Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

8) Why has the one gene–one polypeptide hypothesis been modified in recent years? a) It was found that RNA was the genetic material, not DNA. b) Genes can be spliced differently to generate a variety of related polypeptides. c) Enzymes sometimes consist of more than one polypeptide, each of which is coded for by its own gene. d) Enzymes actually code for genes. e) Polypeptides code for genes.

Answer: b Difficulty: Medium Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

9) A “sense” RNA for a particular targeted protein is ___________. a) an RNA having a sequence complementary to the mRNA of the targeted protein b) the sequence of the mRNA that encoded the protein being targeted c) a small RNA with a clover shape d) an RNA always possessing catalytic activity e) an RNA generally found in ribosomes that forges the peptide bond Answer: b Difficulty: Easy Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

10) The enzyme that is responsible for the synthesis of RNA from a DNA template is called _______. a) DNA-dependent DNA polymerase b) DNA-dependent RNA polymerase c) RNA-dependent RNA polymerase d) RNA-dependent DNA polymerase e) ribonuclease Answer: b Difficulty: Easy Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

11) In what direction is an mRNA molecule synthesized?

a) 3' to 5' direction b) 5' to 3' direction c) N-terminal to C-terminal direction d) C-terminal to N-terminal direction e) N-terminal to 3' direction Answer: b Difficulty: Easy Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

12) The site on DNA to which RNA polymerase binds before initiating transcription is called the ______. a) terminator b) operator c) promoter d) enhancer e) silencer Answer: c Difficulty: Easy Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

13) What provides the energy that drives the polymerization of RNA from a DNA template? a) nitrogenous base breakdown b) deoxyribonucleoside triphosphate (dNTPs) bond breakage c) ribonucleoside triphosphate (NTPs) bond breakage d) ribose sugar hydrolysis e) ribosome hydrolysis Answer: c Difficulty: Medium

Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

14) The reverse reaction of nucleic acid synthesis almost never happens. What prevents it? a) The enzyme does not work in reverse. b) Polynucleotides are too stable to depolymerize. c) H bonds holding the strands together are too strong. d) Nucleic acid synthesis is coupled to the highly exergonic pyrophosphate hydrolysis. e) There is a large uptake of free energy.

Answer: d Difficulty: Hard Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

15) RNA polymerase is a processive enzyme which means that a) it binds loosely to the DNA so it can slip off after each nucleotide. b) it binds tightly to DNA so it only associates with one nucleotide. c) it attaches to DNA for long stretches and moves from nucleotide to nucleotide. d) it processes DNA templates into RNA or DNA. e) it rapidly processes the entire DNA template at once.

Answer: c Difficulty: Easy Learning Objective: LO 11.1 Describe the flow of information in a cell from DNA to RNA to protein.

Section Reference: Section 11.1 The Relationships Among Genes, Proteins, and RNAs

16) Once the s factor leaves the core enzyme, what happens? a) Transcription begins. b) The core enzyme continues RNA elongation. c) The core enzyme discontinues synthesis. d) Transcription terminates.

e) The core enzyme backs up 25 nucleotides.

Answer: b Difficulty: Medium Learning Objective: LO 11.2 Compare the process of transcription in prokaryotic cells and eukaryotic cells.

Section Reference: Section 11.2 An Overview of Transcription in Both Prokaryotic and Eukaryotic Cells

17) The nucleotide at which transcription is initiated is called _____. a) 0 b) +1 c) –1 d) +2 e) –2 Answer: b Difficulty: Easy Learning Objective: LO 11.2 Compare the process of transcription in prokaryotic cells and eukaryotic cells.

Section Reference: Section 11.2 An Overview of Transcription in Both Prokaryotic and Eukaryotic Cells

18) Sequences of DNA that are conserved and seen upstream of a transcription initiation site in roughly the same location from gene to gene in bacteria are called ________. a) familiar sequences b) conserved sequences c) consensus sequences d) avatars e) consensons Answer: c Difficulty: Medium Learning Objective: LO 11.2 Compare the process of transcription in prokaryotic cells and eukaryotic cells.

Section Reference: Section 11.2 An Overview of Transcription in Both Prokaryotic and Eukaryotic Cells

19) The _______ is located about 10 bases upstream from the initiation site. It has the consensus sequence ______ and is responsible for identifying the precise nucleotide at which ________ begins. a) Pribnow box, TATAAT, transcription b) Pribnow box, TTGACA, transcription c) Pribnow box, TATAAT, translation d) Portnoy box, TATAAT, transcription e) Portnoy box, TATAAT, translation Answer: a Difficulty: Hard Learning Objective: LO 11.2 Compare the process of transcription in prokaryotic cells and eukaryotic cells.

Section Reference: Section 11.2 An Overview of Transcription in Both Prokaryotic and Eukaryotic Cells

20) Once bound to the promoter, core RNA polymerase ________. a) breaks the DNA chain in the start site region b) melts the two DNA strands in the start site region c) degrades the two DNA strands in the start site region d) melts the two DNA strands in the termination site region Answer: b Difficulty: Medium Learning Objective: LO 11.2 Compare the process of transcription in prokaryotic cells and eukaryotic cells.

Section Reference: Section 11.2 An Overview of Transcription in Both Prokaryotic and Eukaryotic Cells

21) The combination of DNA, RNA core enzyme and s factor is called a) an open complex b) a transcription unit c) a translation unit d) a coding unit

_____.

e) a transcriptosome Answer: b Difficulty: Easy Learning Objective: LO 11.2 Compare the process of transcription in prokaryotic cells and eukaryotic cells.

Section Reference: Section 11.2 An Overview of Transcription in Both Prokaryotic and Eukaryotic Cells

22) What percentage of cellular RNA is rRNA? a) less than 20% b) more than 80% c) 50-60% d) approximately 35% Answer: c Difficulty: Easy Learning Objective: LO 11.3 Explain the processing of ribosomal and transfer RNA molecules.

Section Reference: Section 11.3 Synthesis and Processing of Eukaryotic Ribosomal and Transfer RNAs

23) Most cellular RNA is in what form? a) hnRNA b) snoRNA c) mRNA d) rRNA e) hmRNA Answer: d Difficulty: Medium Learning Objective: LO 11.3 Explain the processing of ribosomal and transfer RNA molecules.

Section Reference: Section 11.3 Synthesis and Processing of Eukaryotic Ribosomal and Transfer RNAs

24) The chromosome regions containing most rDNA are gathered in __________.

a) terminators b) nucleoli c) nucleosomes d) ribostores e) telomeres Answer: b Difficulty: Easy Learning Objective: LO 11.3 Explain the processing of ribosomal and transfer RNA molecules.

Section Reference: Section 11.3 Synthesis and Processing of Eukaryotic Ribosomal and Transfer RNAs

25) A larger S value (Svedberg unit) for an RNA indicates that the RNA __________. a) migrates more rapidly through a field of force during centrifugation b) migrates less rapidly through a field of force during centrifugation c) migrates more rapidly through a field of force during gel filtration d) migrates more rapidly through a field of force during SDS polyacrylamide gel electrophoresis e) migrates less rapidly through a field of force during SDS polyacrylamide gel electrophoresis Answer: a Difficulty: Medium Learning Objective: LO 11.3 Explain the processing of ribosomal and transfer RNA molecules.

Section Reference: Section 11.3 Synthesis and Processing of Eukaryotic Ribosomal and Transfer RNAs

26) Pre-rRNAs have more ___________ than other RNA transcripts. a) pseudouridine residues and thymidine residues b) thymidine residues and methylated nucleotides c) pseudouridine residues and methylated nucleotides d) pseudouridines and pseudocytosines e) methylated nucleotides and pseudocytosines Answer: c Difficulty: Medium Learning Objective: LO 11.3 Explain the processing of ribosomal and transfer RNA molecules.

Section Reference: Section 11.3 Synthesis and Processing of Eukaryotic Ribosomal and Transfer RNAs

27) Modifications to the nucleotides of pre-rRNAs are made _________. a) after translation b) before transcription c) after transcription d) after mitosis e) before mitosis Answer: c Difficulty: Easy Learning Objective: LO 11.3 Explain the processing of ribosomal and transfer RNA molecules.

Section Reference: Section 11.3 Synthesis and Processing of Eukaryotic Ribosomal and Transfer RNAs

28) In mammalian cells employed in pulse-chase experiments, radiolabeled methyl groups appear first in which size RNA molecule that is a precursor to rRNA? a) 65S RNA b) 45S RNA c) 28S RNA d) 18S RNA e) 5.8S RNA Answer: b Difficulty: Medium Learning Objective: LO 11.3 Explain the processing of ribosomal and transfer RNA molecules.

Section Reference: Section 11.3 Synthesis and Processing of Eukaryotic Ribosomal and Transfer RNAs

29) What is the name of the RNA-degrading machine that consists of nearly a dozen different exonucleases and is thought to execute some of the enzymatic cleavages that occur during pre-rRNA processing? a) endosome b) exosome

c) nucleosome d) heliosome e) degradosome Answer: b Difficulty: Easy Learning Objective: LO 11.3 Explain the processing of ribosomal and transfer RNA molecules.

Section Reference: Section 11.3 Synthesis and Processing of Eukaryotic Ribosomal and Transfer RNAs

30) How would you describe the arrangement of the 5S rRNA genes? a) tandem array with spacers b) continuous genes c) tandem array without spacers d) 4 introns between each protein e) quartile array with duplex spacers Answer: a Difficulty: Medium Learning Objective: LO 11.3 Explain the processing of ribosomal and transfer RNA molecules.

Section Reference: Section 11.3 Synthesis and Processing of Eukaryotic Ribosomal and Transfer RNAs

31) A cluster of genes coding for tRNAs is often referred to as ______. a) tDNA b) transferase c) rDNA d) t clusters e) tDNase Answer: a Difficulty: Easy Learning Objective: LO 11.3 Explain the processing of ribosomal and transfer RNA molecules.

Section Reference: Section 11.3 Synthesis and Processing of Eukaryotic Ribosomal and Transfer RNAs

32) The promoter for tRNA genes (tDNA) is located ________. a) at the 3' end of the gene b) within the coding section of the gene c) at the 5' end of the gene d) far downstream of the gene e) far upstream of the gene Answer: b Difficulty: Medium Learning Objective: LO 11.3 Explain the processing of ribosomal and transfer RNA molecules.

Section Reference: Section 11.3 Synthesis and Processing of Eukaryotic Ribosomal and Transfer RNAs

33) You incubate eukaryotic cells for 30 minutes in [3H]uridine and then immediately kill the cells and extract the RNA. Where does the radiolabel appear after this experiment? a) in larger molecular weight RNAs in the nucleus b) in smaller molecular weight RNAs in the mitochondria c) in smaller molecular weight RNAs in the cytoplasm d) in larger molecular weight RNAs in the mitochondria e) in moderately sized RNAs in the Golgi complex Answer: a Difficulty: Hard Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

34) Heterogeneous nuclear RNAs (hnRNAs) are _________. a) tRNA precursors b) mRNA precursors c) rRNA precursors d) snoRNA precursors e) mature snRNAs Answer: b Difficulty: Medium

Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

35) How would you describe the half-lives of rRNAs and tRNAs? a) days or weeks long b) minutes long c) seconds long d) hours long e) years long Answer: a Difficulty: Medium Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

36) Which enzyme is responsible for synthesizing hnRNAs? a) RNA polymerase I b) RNA polymerase II c) RNA polymerase III d) reverse transcriptase e) general transcription factors Answer: b Difficulty: Easy Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

37) RNA polymerase II promoters are located on the ________ side of each transcription unit. a) 3' b) 5' c) N-terminal d) C-terminal Answer: b

Difficulty: Medium Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

38) Why are general transcription factors (GTFs) referred to as "general?" a) The same transcription factors are required for the accurate initiation of transcription of a diverse array of genes in a wide variety of different organisms. b) The same transcription factors are required for the accurate initiation of translation of a diverse array of genes in a wide variety of different organisms. c) The same transcription factors are required for the accurate termination of transcription of a diverse array of genes in a wide variety of different organisms. d) The same transcription factors are required for the accurate termination of translation of a diverse array of genes in a wide variety of different organisms.

Answer: a Difficulty: Medium Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

39) What molecule is TFIIH known to phosphorylate? a) a G protein b) RNA polymerase II c) peptidyltransferase d) DNA helicase Answer: b Difficulty: Hard Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

40) Where is the RNA polymerase II phosphorylated during its activation? a) on the N-terminal end of the largest RNA polymerase II subunit b) on the central 20 amino acids of the largest RNA polymerase II subunit c) on the 3' end of the largest RNA polymerase II subunit d) on the 5' end of the largest RNA polymerase II subunit

e) in the carboxyl-terminal domain (CTD) of the largest RNA polymerase II subunit Answer: e Difficulty: Medium Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

41) Which of the following is NOT a normal property of eukaryotic mRNAs? a) They contain a continuous nucleotide sequence encoding a specific polypeptide. b) They are found in the cytoplasm and inside the Golgi complex. c) They are attached to ribosomes when they are translated. d) Most have a significant noncoding segment that does not direct assembly of amino acids. e) They have special modifications at their 5' and 3' termini.

Answer: b Difficulty: Medium Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

42) The 3' end of most eukaryotic mRNAs contains a _________, while the 5' end has a _________. a) poly(A) tail, methylated guanosine cap b) poly(U) tail, methylated guanosine cap c) methylated guanosine cap, poly(A) tail d) poly(A) tail, sulfonated guanosine cap e) methylated guanosine cap, poly(U) tail Answer: a Difficulty: Medium Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

43) Which of the following binds to the TATA box? a) CTD

b) tRNA c) corticosteroid binding protein d) TBP e) PBT Answer: d Difficulty: Easy Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

44) The intermediate stage that the group II introns pass through while undergoing self-splicing is called the _____. a) langolier b) lanyard c) lariat d) lasso Answer: c Difficulty: Easy Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

45) The macromolecular complex that associates with each intron and splices it is called __________. a) a splicer b) an acrosome c) a spliceosome d) a splicing body e) a splice engine Answer: c Difficulty: Easy Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

46) As life was first evolving, what molecule is thought to have performed double duty as the genetic material and catalyst of chemical reactions? a) RNA b) proteins c) polypeptides d) DNA e) both proteins and polypeptides Answer: a Difficulty: Easy Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

47) Which of the phenomena below is responsible for the ability of one gene to code for more than one polypeptide? a) transcription b) alternative splicing c) transposition d) hybridization e) exon shuffling Answer: b Difficulty: Easy Learning Objective: LO 11.4 Describe the synthesis and structure of eukaryotic mRNA. Section Reference: Section 11.4 Synthesis and Structure of Eukaryotic Messenger RNAs

48) RNA interference can be used to __________ the production of a particular enzyme, allowing the effect of ___________ of the enzyme on the organism's _________ to be determined. a) stop, deficiency, phenotype b) enhance, deficiency, phenotype c) stop, deficiency, genotype d) enhance, overexpression, phenotype e) stop, overexpression, genotype Answer: a

Difficulty: Hard Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

49) RNAi or dsRNA-mediated RNA interference is an example of a broader phenomenon that occurs widely in eukaryotes called __________. a) RNA activation b) RNA ascension c) RNA silencing d) RNA sussuration e) RNA quieting Answer: c Difficulty: Easy Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

50) Why does it make sense that cells would respond to the presence of dsRNAs with a mechanism such as RNAi? a) dsRNAs are not produced by the cell's normal genetic activities. b) dsRNAs are produced by the cell's normal genetic activities. c) dsRNAs adversely affect mitochondria. d) dsRNAs could cause degradation of nuclear DNA. e) dsRNAs have a very abnormal interaction with proteins.

Answer: a Difficulty: Hard Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

51) What is the name of the enzyme that cleaves dsRNA into the small, double-stranded fragments known as small-interfering RNAs (siRNAs)?

a) riboendonuclease b) Dicer ribonuclease c) deoxyribonuclease d) RNA helicase e) reverse transcriptase Answer: b Difficulty: Easy Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

52) What appears to be the role of siRNA in destroying the target mRNA upon which it and its associated proteins act? a) It cleaves the target mRNA. b) It stabilizes the target mRNA. c) It destabilizes the target mRNA's binding to its associated proteins. d) It guides the RISC that cleaves the target mRNA to that target mRNA due to its complementarity to that molecule. e) It activates the RISC complex ribonuclease.

Answer: d Difficulty: Hard Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

53) Which strand of the double-stranded siRNA is cut in two and then dissociates from the pre-RISC? a) the active strand b) the passenger strand c) the siRNA strand d) the pedestrian strand e) the silencer strand Answer: b Difficulty: Easy

Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

54) How is the RISC directed to the target mRNA that it is destined to destroy? a) The ribonuclease slicer directs the RISC to the cleavage site. b) The single-stranded siRNA is complementary to the target mRNA and directs the RISC to it. c) The passenger strand acts like a guide to direct the RISC to the target. d) The siRNA is complementary to the slicer ribonuclease. e) The siRNA is magnetically attracted to the target mRNA. Answer: b Difficulty: Medium Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

55) It is generally accepted that vertebrates do not utilize RNAi as a defense against viruses for what reason? a) Vertebrates have no serious viral infections. b) Vertebrate cell membranes resist viral attachment. c) Vertebrate cell walls resist viral attachment. d) Vertebrates rely instead on a well-developed immune system.

Answer: d Difficulty: Easy Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

56) Mammalian oocytes have recently been shown to produce siRNAs. What are they called? a) exo-siRNAs b) endo-siRNAs c) endoRNAs d) mamma-siRNAs

e) oo-siRNAs Answer: b Difficulty: Medium Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

57) What is the presumed function of the siRNAs produced by mammalian oocytes? a) They aid in fertilization. b) They defend against the movement of transposable elements in the female germ cell line. c) They defend against the movement of chromosomes in the female germ cell line. d) They play a role in the regulation of meiosis. e) They play a role in the regulation of oogenesis.

Answer: b Difficulty: Medium Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

58) A small RNA encoded by the lin-4 gene was found in the nematode C. elegans. It was nearly complementary to segments in ________. These small RNAs were able to bind to the complementary mRNA, blocking its translation, which apparently triggers a transition to the next developmental stage. a) the 3' untranslated region of specific mRNAs produced by the organism b) the 5' untranslated region of specific mRNAs produced by the organism c) the promoter of specific genes d) the poly(A) tail of specific mRNAs e) the 5'-methylguanosine cap of the mRNA Answer: a Difficulty: Medium Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

59) A pri-miRNA is cleaved within the nucleus by an enzyme called _______ into a shorter, double-stranded, hairpin-shaped precursor called a ________. a) Drosha, pre-miRNA b) Drosha, pri-miRNA c) Dicer, pre-miRNA d) Dicer, pri-miRNA e) Slicer, pre-miRNA Answer: a Difficulty: Medium Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

60) Where is the pre-miRNA converted to miRNA by Dicer? a) the nucleus b) the cytoplasm c) the mitochondria d) the plasma membrane e) the lysosome Answer: b Difficulty: Easy Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

61) With what protein does the double-stranded miRNA become associated? The RNA duplex then is disassembled and one of the single strands is incorporated into a RISC complex. a) slicer b) Mincer c) an Argonaute protein d) riscin e) ribonuclease

Answer: c Difficulty: Easy Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

62) Which enzyme, also responsible for siRNA formation, carves miRNAs from their double-stranded, fold-back RNA precursor (pre-miRNA)? a) RNA polymerase b) reverse transcriptase c) Dicer ribonuclease d) Drosha polymerase e) Mincer ribonuclease Answer: c Difficulty: Medium Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

63) What is this difference between si/miRNAs and piRNAs? a) piRNAs are longer than si/miRNAs. b) The majority of mammalian piRNAs can be mapped to a small number of huge genomic loci, unlike si/mi RNAs. c) The formation of piRNAs does not involve the formation of dsRNA precursors, unlike si/mi RNAs. d) Formation of piRNAs does not involve cleavage by Dicer ribonuclease, but instead it depends on the endonuclease activity of the PIWI protein acting on a long, single stranded primary transcript. e) All of these are correct.

Answer: e Difficulty: Medium Learning Objective: LO 11.5 Explain the role of RNA interference in the regulation of gene expression.

Section Reference: Section 11.5 RNA Interference

64) Which event is considered to be non-cell autonomous? a) movement of mRNA between plant cells b) movement of siRNAs between plant cells c) compartmentalization of miRNAs in single plant cells d) all are correct choices Answer: b Difficulty: Medium Learning Objective: LO 11.6 Identify the role of plasmodesmata in long-range siRNA movement..

Section Reference: Section 11.6 Green Cells: Long-Range siRNA movement

65) Which molecule in plant cells has been linked with cell-to-cell movement of siRNA molecules? a) Dicer DCL4 b) Drosha DCL6 c) Zucchini d) RNA polymerase RDR8 Answer: a Difficulty: Medium Learning Objective: LO 11.6 Identify the role of plasmodesmata in long-range siRNA movement..

Section Reference: Section 11.6 Green Cells: Long-Range siRNA movement

66) The CRISPR-cas9 system uses _______ as a template to locate and cleave specific___________ targets. a) siRNA, DNA b) siRNA, RNA c) dsDNA, RNA d) sgRNA, RNA e) sgRNA, DNA Answer: e Difficulty: Easy

Learning Objective: LO 11.7 Describe the transcriptome and its relationship to noncoding RNAs. Section Reference: Section 11.7 CRISPR and other Noncoding RNAs

67) Which of the following is a correct statement about the CRISPR-cas9 system? a) The CRISPR-cas9 system is only capable of DNA insertions. b) The CRISPR-cas9 system was originally discovered in eukaryotes. c) The CRISPR-cas9 system protects bacteria from viral infection d) The CRISPR-cas9 system randomly cuts DNA at any sequence location Answer: c Difficulty: Medium Learning Objective: LO 11.7 Describe the transcriptome and its relationship to noncoding RNAs. Section Reference: Section 11.7 CRISPR and other Noncoding RNAs

68) You discover alien life with a genetic system based on a DNA-like molecule, but it has 6 bases instead of 4 as happens on Earth. The proteins on the planet are built from combinations of 30 possible amino acids. What would be the minimum number of bases in each codon on this planet? a) 1 b) 2 c) 3 d) 4 e) 6 Answer: b Difficulty: Hard Learning Objective: LO 11.8 Explain how the redundancy of the genetic code can provide protection from mutation.

Section Reference: Section 11.8 Encoding Genetic Information

69) What evidence shows that the genetic code is not overlapping? a) Mutant proteins whose genes experience a change in only one nucleotide have a corresponding change in 3 consecutive amino acids. b) Mutant proteins whose genes experience a change in only one nucleotide have a corresponding change in only 1 amino acid. c) Mutant proteins are greatly increased in length relative to the nonmutated version.

d) Mutant proteins are greatly decreased in length relative to the nonmutated version. e) Mutant proteins whose genes experience a change in only one nucleotide have a corresponding change in 6 consecutive amino acids.

Answer: b Difficulty: Hard Learning Objective: LO 11.8 Explain how the redundancy of the genetic code can provide protection from mutation.

Section Reference: Section 11.8 Encoding Genetic Information

70) The genetic code has 64 codons, while there are only 20 amino acids. Thus, some amino acids are coded for by more than one codon. As a result, the genetic code is said to be ________. a) regenerate b) degenerate c) overlapping d) nonoverlapping e) nonspecific Answer: b Difficulty: Easy Learning Objective: LO 11.8 Explain how the redundancy of the genetic code can provide protection from mutation.

Section Reference: Section 11.8 Encoding Genetic Information

71) How many codons code for an amino acid? a) 20 b) 3 c) 64 d) 61 e) 21 Answer: d Difficulty: Hard Learning Objective: LO 11.8 Explain how the redundancy of the genetic code can provide protection from mutation.

Section Reference: Section 11.8 Encoding Genetic Information

72) What is the maximum number of tRNAs that a cell would be likely to have? a) 20 b) 3 c) 64 d) 61 e) 21 Answer: d Difficulty: Medium Learning Objective: LO 11.8 Explain how the redundancy of the genetic code can provide protection from mutation.

Section Reference: Section 11.8 Encoding Genetic Information

73) Before the genetic code was actually known, Francis Crick predicted that it was degenerate.

What piece of evidence led him to make this prediction? a) All proteins looked the same. b) All proteins were made of amino acids. c) He noted that the base composition of the DNAs of various bacteria varied greatly while the amino acid composition of their proteins varied much less. d) He noted that the base composition of the DNAs of various bacteria varied little while the amino acid composition of their proteins varied greatly overall. e) The code was non-overlapping.

Answer: c Difficulty: Hard Learning Objective: LO 11.8 Explain how the redundancy of the genetic code can provide protection from mutation.

Section Reference: Section 11.8 Encoding Genetic Information

74) What does it mean to say the genetic code is universal? a) The genetic code is the same everywhere in the Universe. b) All of the organisms on Earth use the same genetic code with only minor variations. c) The genetic code is found in all organisms but varies extensively. d) The genetic code is minimal.

e) The genetic code is multiphasic.

Answer: b Difficulty: Medium Learning Objective: LO 11.8 Explain how the redundancy of the genetic code can provide protection from mutation.

Section Reference: Section 11.8 Encoding Genetic Information

75) Another name for protein synthesis is _________. a) transcription b) transition c) transubstantiation d) translation e) transition state Answer: d Difficulty: Easy Learning Objective: LO 11.9 Describe the role of transfer RNAs in protein synthesis.

Section Reference: Section 11.9 Decoding the Codons: The Role of Transfer RNAs

76) Where are the unusual bases of tRNAs predominantly concentrated? a) in the stems b) in the loops c) at the 3' end d) at the 5' end e) in double-stranded regions Answer: b Difficulty: Easy Learning Objective: LO 11.9 Describe the role of transfer RNAs in protein synthesis.

Section Reference: Section 11.9 Decoding the Codons: The Role of Transfer RNAs

77) What is the supposed function of the loops in tRNAs? a) They bind to amino acids.

b) They bind to other tRNAs. c) They bind to mRNAs. d) They serve as potential recognition sites for various proteins. e) They increase the buoyant density of tRNAs. Answer: d Difficulty: Medium Learning Objective: LO 11.9 Describe the role of transfer RNAs in protein synthesis.

Section Reference: Section 11.9 Decoding the Codons: The Role of Transfer RNAs

78) How do the unusual bases found in the loops in tRNA influence tRNA structure? a) They disrupt H bond formation in the loop regions, causing the loops to form. b) They bind to proteins that hold the loops open. c) They disrupt hydrophobic interactions in the loop regions, causing the loops to form. d) They prevent van der Waals interactions which prevent loop formation. e) They disrupt H bond formation which causes complementary pairing in the stem regions.

Answer: a Difficulty: Medium Learning Objective: LO 11.9 Describe the role of transfer RNAs in protein synthesis.

Section Reference: Section 11.9 Decoding the Codons: The Role of Transfer RNAs

79) A tRNA has an anticodon with the sequence 3'-UAC-5'. What would be the sequence of the complementary codon? a) 3'-UAC-5' b) 3'-AUG-5' c) 5'-AUG-3' d) 5'-AUC-3' e) 5'-ATG-3' Answer: c Difficulty: Medium Learning Objective: LO 11.9 Describe the role of transfer RNAs in protein synthesis.

Section Reference: Section 11.9 Decoding the Codons: The Role of Transfer RNAs

80) The greatest similarities among codons that specify the same amino acid occur in the _________ of the triplet. a) first two nucleotides b) last two nucleotides c) first and third nucleotides d) third nucleotide e) middle nucleotide Answer: a Difficulty: Medium Learning Objective: LO 11.9 Describe the role of transfer RNAs in protein synthesis.

Section Reference: Section 11.9 Decoding the Codons: The Role of Transfer RNAs

81) The greatest variability among codons that specify the same amino acid occurs in the _________ of the triplet. a) first two nucleotides b) last two nucleotides c) first and last nucleotides d) last nucleotide e) middle nucleotide Answer: d Difficulty: Medium Learning Objective: LO 11.9 Describe the role of transfer RNAs in protein synthesis.

Section Reference: Section 11.9 Decoding the Codons: The Role of Transfer RNAs

82) What is the significance of the variability of the third nucleotide in a codon? a) Each tRNA can recognize and bind its own codon. b) Each tRNA can recognize and bind its own amino acid. c) The same tRNA can recognize more than one codon. d) The same tRNA can recognize more than one anticodon. e) The same anticodon can recognize more than one amino acid.

Answer: c Difficulty: Hard Learning Objective: LO 11.9 Describe the role of transfer RNAs in protein synthesis.

Section Reference: Section 11.9 Decoding the Codons: The Role of Transfer RNAs

83) Based on the interchangeability of the nucleotide at the third position, Francis Crick proposed that the same tRNA may be able to recognize more than one codon. What was his proposal called? a) the tRNA theory b) the wobble hypothesis c) the steric hindrance hypothesis d) the chemiosmotic hypothesis e) the endosymbiotic hypothesis Answer: b Difficulty: Easy Learning Objective: LO 11.9 Describe the role of transfer RNAs in protein synthesis.

Section Reference: Section 11.9 Decoding the Codons: The Role of Transfer RNAs

84) What enzyme is responsible for covalently linking amino acids to the 3'-end of the cognate tRNA? a) peptidyltransferase b) aminoacyl-tRNA synthetase c) glutamine synthetase d) RNA polymerase e) ATP synthase Answer: b Difficulty: Medium Learning Objective: LO 11.9 Describe the role of transfer RNAs in protein synthesis.

Section Reference: Section 11.9 Decoding the Codons: The Role of Transfer RNAs

85) Which of the following is NOT required for protein synthesis? a) various tRNAs with their attached amino acids b) ribosomes c) mRNA d) anions e) GTP

Answer: d Difficulty: Medium Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

86) What are the three distinct activities of protein synthesis in the correct order? a) initiation, elongation, termination b) termination, initiation, elongation c) initiation, termination, elongation d) elongation, initiation, termination e) elongation, termination, initiation Answer: a Difficulty: Medium Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

87) Which codon below usually serves as the initiation codon? a) 5'-AUG-3' b) 5'-GUG-3' c) 3'-AUG-5' d) 3'-GUG-3' e) 3'-UAC-5' Answer: a Difficulty: Easy Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

88) What is the name of the nucleotide sequence that helps the 30S ribosomal subunit find the initiation codon on bacterial mRNAs?

a) the Watson-Crick sequence b) the Hershey-Chase sequence c) the Hatch-Slack sequence d) the Shine-Dalgarno sequence e) the Franklin sequence Answer: d Difficulty: Medium Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

89) Which bacterial initiation factor facilitates attachment of the 30S subunit to the mRNA and may prevent the aminoacyl-tRNA from entering the wrong site on the ribosome? a) IF2 b) IF1 c) IF3 d) eIF2 e) IF4 Answer: b Difficulty: Easy Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

90) Which is always the first amino acid incorporated at the N-terminus of a nascent polypeptide chain? a) cysteine b) cystine c) methionine d) asparagine e) glycine Answer: c Difficulty: Easy

Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

91) What chemical group is attached to the first methionine in a polypeptide chain in prokaryotes? a) a formyl group b) a methyl group c) an acetyl group d) a phosphate group e) a glutamyl group Answer: a Difficulty: Easy Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

92) The initiator tRNA enters the 30S ribosomal subunit at the __________ during prokaryotic protein synthesis. a) A site b) P site c) E site d) Q site e) 50S attachment point Answer: b Difficulty: Easy Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

93) What drives the conformational shift that is required for the release of the IF2-GDP initiation factor from the prokaryotic initiation complex? a) hydrolysis of ATP bound to IF2

b) hydrolysis of the GTP bound to IF2 c) binding of IF1 d) degradation of IF3 e) GDP condensation Answer: b Difficulty: Medium Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

94) The mechanical changes that ribosomes undergo are driven by energy from ______. a) GTP hydrolysis b) ATP hydrolysis c) ADP hydrolysis d) an electrochemical gradient e) a concentration gradient Answer: a Difficulty: Easy Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

95) The surfaces of the two ribosomal subunits that face one another contain the binding sites for the mRNA and incoming tRNAs and are thus key for the function of the ribosomes. The fact that these surfaces consist largely of RNA supports what proposal? a) primordial ribosomes were composed solely of proteins b) primordial ribosomes were composed exclusively of RNA c) primordial ribosomes were composed exclusively of DNA d) prokaryotes gave rise to eukaryotes e) endosymbiosis gave rise to eukaryotes Answer: b Difficulty: Medium Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

96) It has been discovered that some mRNAs have a signal that causes the ribosome to change its reading frame by backing up or moving ahead one base. Such a sequence is called _________. a) a recentering signal b) a recoding signal c) an acentric signal d) an acentric sequence e) an allopatric sequence Answer: b Difficulty: Easy Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

97) Which amino acid can be converted to selenocysteine after its attachment to its tRNA? a) serine b) alanine c) phenylalanine d) cysteine e) cystine Answer: a Difficulty: Medium Learning Objective: LO 11.10 Outline the translation of genetic information from initiation through termination.

Section Reference: Section 11.10 Translating Genetic Information

98) Technology which uses DNA for the engineering of nanostructures and new materials is referred to as ______________. a) DNA sudoku b) DNA mah-jong c) DNA origami d) DNA jig-saw

Answer: c Difficulty: Easy Learning Objective: LO 11.11 Explain how DNA origami is used to build nanostructures.

Section Reference: Section 11.11 Engineering Linkage: DNA Origami

Question Type: Multiple Select

99) Through which structures have plant siRNAs been observed to spread to distant cells?

(Select all correct choices) a) xylem tissue b) phloem tissue c) plasmodesmata d) guard cell pores Answer: b, c Difficulty: Medium Learning Objective: LO 11.6 Identify the role of plasmodesmata in long-range siRNA movement..

Section Reference: Section 11.6 Green Cells: Long-Range siRNA movement

Question Type: Multiple Select

100) DNA origami technology relies on the use of _________________. choices)

(Select all correct

a) circles of dsDNA b) circles of ssDNA c) linear strands of ssDNA d) linear strands of dsDNA Answer: b, c Difficulty: Easy Learning Objective: LO 11.11 Explain how DNA origami is used to build nanostructures.

Section Reference: Section 11.11 Engineering Linkage: DNA Origami

Question Type: Multiple Select

101) Potential applications of DNA origami technology include:

(Select all correct choices)

a) design of antiviral medications b) creation of novel nanocircuitry for electronics c) CRISPR-cas9 applications d) designing small containers to study protein-protein motor interactions Answer: b, d Difficulty: Medium Learning Objective: LO 11.11 Explain how DNA origami is used to build nanostructures.

Section Reference: Section 11.11 Engineering Linkage: DNA Origami

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 12

Question Type: Multiple Choice

1) What is the name of the linkage than holds the lactose disaccharide together? a) β-galactoside linkage b) α-lipophilic linkage c) β-glycosidic linkage d) α-galactoside linkage e) ester linkage Answer: a Difficulty: Easy Learning Objective: LO 12.1 Describe the components and control mechanisms of repressible and inducible operons.

Section Reference: Section 12.1 Control of Gene Expression in Bacteria

2) Which two monosaccharides combine to form lactose? a) 2 glucose molecules b) glucose and galactose c) galactose and fructose d) 2 galactose molecules e) glucose and fructose Answer: b Difficulty: Easy Learning Objective: LO 12.1 Describe the components and control mechanisms of repressible and inducible operons.

Section Reference: Section 12.1 Control of Gene Expression in Bacteria

3) A section of a bacterial chromosome in which genes for the enzymes of a particular metabolic pathway are clustered together in a functional complex under coordinate control is called ______. a) an operator b) an operon c) a promoter d) a repressor e) an activator Answer: b Difficulty: Easy Learning Objective: LO 12.1 Describe the components and control mechanisms of repressible and inducible operons.

Section Reference: Section 12.1 Control of Gene Expression in Bacteria

4) What is the name of the site where RNA polymerase binds to the DNA prior to the beginning of transcription? a) the operator b) the terminator c) the promoter d) the repressor e) the structural genes Answer: c Difficulty: Easy Learning Objective: LO 12.1 Describe the components and control mechanisms of repressible and inducible operons.

Section Reference: Section 12.1 Control of Gene Expression in Bacteria

5) The operator is the site on the __________. a) DNA where the repressor binds b) DNA where DNA polymerase binds c) DNA where reverse transcriptase binds d) RNA where the repressor binds e) ribosome where the polymerase binds Answer: a

Difficulty: Easy Learning Objective: LO 12.1 Describe the components and control mechanisms of repressible and inducible operons.

Section Reference: Section 12.1 Control of Gene Expression in Bacteria

6) Which site in a bacterial operon is adjacent to or overlaps with a promoter? a) operator b) terminator c) activator d) repressor e) structural genes Answer: a Difficulty: Easy Learning Objective: LO 12.1 Describe the components and control mechanisms of repressible and inducible operons.

Section Reference: Section 12.1 Control of Gene Expression in Bacteria

7) What is the name of the regulatory protein which binds to specific DNA sequences with high affinity and plays an important role in determining whether a genome segment is transcribed or not? a) the operator b) the terminator c) the promoter d) the repressor e) the structural genes Answer: d Difficulty: Easy Learning Objective: LO 12.1 Describe the components and control mechanisms of repressible and inducible operons.

Section Reference: Section 12.1 Control of Gene Expression in Bacteria

8) The lac operon is an example of _______ operon.

a) a noninducible b) a constitutive c) an inducible d) a repressible e) an irrepressible Answer: c Difficulty: Easy Learning Objective: LO 12.1 Describe the components and control mechanisms of repressible and inducible operons.

Section Reference: Section 12.1 Control of Gene Expression in Bacteria

9) β-galactosidase is encoded by the ___________. a) y gene of the lac operon b) z gene of the lac operon c) a gene of the lac operon d) y gene of the trp operon e) z gene of the trp operon Answer: b Difficulty: Easy Learning Objective: LO 12.1 Describe the components and control mechanisms of repressible and inducible operons.

Section Reference: Section 12.1 Control of Gene Expression in Bacteria

10) How do allolactose and lactose differ? a) They are composed of different sugars. b) Allolactose has a negative charge, while lactose has a positive charge. c) The type of linkage holding the two constituent sugars together differs between lactose and allolactose. d) The order of the sugars is reversed in the two molecules. e) The constituent sugars are both upside down in lactose and right-side-up in allolactose.

Answer: c Difficulty: Medium Learning Objective: LO 12.1 Describe the components and control mechanisms of repressible and inducible operons.

Section Reference: Section 12.1 Control of Gene Expression in Bacteria

11) When a regulatory protein inhibits transcription, this is known as _________________. a) positive control b) negative control c) averaged control d) circumspect control e) neutral control Answer: b Difficulty: Easy Learning Objective: LO 12.1 Describe the components and control mechanisms of repressible and inducible operons.

Section Reference: Section 12.1 Control of Gene Expression in Bacteria

12) Digital logic relies on all of the following EXCEPT: a) 0,1 binary values b) electronic circuits where voltage switches are ON or OFF c) circuit output regulating input d) AND gates where two input circuits must be active to generate activity past the logic gate e) OR gates where either of two input circuits must be active to generate activity past the logic gate Answer: c Difficulty: Medium Learning Objective: LO 12.2 Explain how gene regulatory mechanisms can be used to reprogram cell behavior.

Section Reference: Section 12.2 Engineering Linkage: Building Digital Logic with Genes

13) What future goals are being considered for cellular engineering attempts to reprogram cellular behavior? a) reprogramming developmental events so that all humans will reach a standardized height b) reprogramming metabolism to eliminate obesity and diabetes c) reprogramming surface receptor responses so that receptor binding might cause tumor cell destruction

d) reprogramming cellular receptors to eliminate infectious disease e) all these options are actively being pursued and researched Answer: c Difficulty: Medium Learning Objective: LO 12.2 Explain how gene regulatory mechanisms can be used to reprogram cell behavior.

Section Reference: Section 12.2 Engineering Linkage: Building Digital Logic with Genes

14) Which of the following does NOT accurately describe the contents of the nucleus? a) viscous b) amorphous c) undistinguished morphology d) crystalline e) highly extended nucleoprotein Answer: d Difficulty: Easy Learning Objective: LO 12.3 Explain how the nuclear pore complex regulates movement of materials.

Section Reference: Section 12.3 Structure of the Nuclear Envelope

15) According to the text, what is the single most important distinction between prokaryotes and eukaryotes? a) the existence of the Golgi complex b) the separation of the cell's genetic material from the surrounding cytoplasm c) the existence of ribosomes d) the centrioles e) the lysosomes and peroxisomes Answer: b Difficulty: Easy Learning Objective: LO 12.3 Explain how the nuclear pore complex regulates movement of materials.

Section Reference: Section 12.3 Structure of the Nuclear Envelope

16) With what structure is the outer membrane of the nuclear envelope continuous? a) Rough endoplasmic reticulum b) Smooth endoplasmic reticulum c) Golgi complex d) the spindle e) the plasma membrane Answer: a Difficulty: Easy Learning Objective: LO 12.3 Explain how the nuclear pore complex regulates movement of materials.

Section Reference: Section 12.3 Structure of the Nuclear Envelope

17) The thin filamentous meshwork that is bound by integral membrane proteins of the inner surface of the nuclear envelope in animal cells is called the _________. a) basement lamina b) basal lamina c) nuclear lamina d) nucleon e) nuclear limulus Answer: c Difficulty: Easy Learning Objective: LO 12.3 Explain how the nuclear pore complex regulates movement of materials.

Section Reference: Section 12.3 Structure of the Nuclear Envelope

18) What is the name of the proteins that make up the nuclear lamina and of what protein superfamily are they a member? a) lamins, laminins b) lamins, intermediate filaments c) keratin, intermediate filaments d) keratin, laminins e) actin, microfilaments Answer: b

Difficulty: Easy Learning Objective: LO 12.3 Explain how the nuclear pore complex regulates movement of materials.

Section Reference: Section 12.3 Structure of the Nuclear Envelope

19) Which of the traits below is characteristic of the classical nuclear localization signals? a) possession of large numbers of hydrophobic amino acids b) possession of one or two short stretches of negatively charged amino acids c) possession of one or two short stretches of positively charged amino acids d) twisted backbones e) double helical regions Answer: c Difficulty: Easy Learning Objective: LO 12.3 Explain how the nuclear pore complex regulates movement of materials.

Section Reference: Section 12.3 Structure of the Nuclear Envelope

20) A transport receptor that moves macromolecules from the cytoplasm to the nucleus is called _______. a) an exhalin b) an exportin c) an importin d) a transportin e) a receptin Answer: c Difficulty: Easy Learning Objective: LO 12.3 Explain how the nuclear pore complex regulates movement of materials.

Section Reference: Section 12.3 Structure of the Nuclear Envelope

21) When an importin α/β complex carries a protein destined to move into the nucleus, what does it bind to when it comes to the outer surface of the nucleus near the nuclear pore complex?

a) the torus b) the outer ring of the nuclear pore complex c) the inner ring of the nuclear pore complex d) cytoplasmic filaments that extend from the outer ring of the nuclear pore complex e) the transporter Answer: d Difficulty: Medium Learning Objective: LO 12.3 Explain how the nuclear pore complex regulates movement of materials.

Section Reference: Section 12.3 Structure of the Nuclear Envelope

22) What energy source is used to maintain the Ran-GTP gradient across the nuclear envelope? a) energy released by ATP hydrolysis b) a proton gradient c) a H+ ion gradient d) energy released by GTP hydrolysis e) an electron gradient Answer: d Difficulty: Medium Learning Objective: LO 12.3 Explain how the nuclear pore complex regulates movement of materials.

Section Reference: Section 12.3 Structure of the Nuclear Envelope

23) What happens if histone H1 is selectively extracted from compacted chromatin? a) chromatin uncoils to form a more extended beaded filament b) chromatin uncoils to form a less extended cylindrical filament c) chromatin completely disassembles to its component nucleotides d) chromatin breaks into small fragments e) chromatin breaks into large fragments Answer: a Difficulty: Medium Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

24) What experimental evidence suggests that the N-terminal tails of histones participate in the formation of higher-order chromatin structure? a) The tails cause histones to denature. b) The tails when acetylated cause the dissolution of the 30-nm fibers. c) Chromatin fibers with histones lacking their tails cannot fold into higher-order fibers. d) Chromatin fibers with histones possessing longer tails cannot fold into higher-order fibers. e) Chromatin fibers lacking tails are shorter.

Answer: c Difficulty: Hard Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

25) What is the name of the gene responsible for the inactivation of the X chromosome? a) INAC b) XIST c) 1STX d) IRS e) XCHR Answer: b Difficulty: Easy Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

26) What distinguishes the regulatory, noncoding RNA that is suspected of being responsible for X chromosome inactivation from other noncoding RNA molecules? a) It is much larger than the other noncoding RNAs. b) It is much smaller than the other noncoding RNAs. c) It is more tightly coiled than the other noncoding RNAs. d) It contains a higher content of uracil than the other noncoding RNAs. e) It contains a higher content of adenine than the other noncoding RNAs.

Answer: a Difficulty: Medium Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

27) There are genes on the X chromosome that manage to escape inactivation. What particular genes are included in this group and what might be the reason that they remain activated? a) genes that are missing from the X chromosome; so they will be expressed equally in both sexes b) genes that are also present on the Y chromosome; so they will be expressed equally in both sexes c) genes that are also found on Chromosome 1; so they will be expressed equally in both sexes d) centromere genes; so that all cells will be able to attach to the spindle e) centromere genes; so they will be expressed equally in both sexes Answer: b Difficulty: Medium Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

28) What evidence suggests that while the XIST gene may be required to initiate X chromosome inactivation, it may not be required to maintain it from one generation to another? a) Tumor cells do not maintain X chromosome inactivation from generation to generation. b) Some tumor cells in women contain inactivated X chromosomes whose XIST gene has been deleted. c) Some tumor cells in women contain inactivated X chromosomes whose XIST gene has been duplicated. d) Some women have patches of cells in their retinas that are color blind and others that are not. e) Some tumor cells in women have no X chromosomes.

Answer: b Difficulty: Hard Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

29) What is thought to maintain X chromosome inactivation? a) repressive histone modifications b) RNA inactivation c) DNA methylation d) localized DNA denaturation e) both repressive histone modifications and DNA methylation Answer: e Difficulty: Easy Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

30) What evidence suggests that RNAi plays a role in heterochromatization? a) Deletion of RNAi components impairs both methylation of histone H3K9 and heterochromatization. b) Addition of RNAi components impairs both methylation of histone H3K9 and heterochromatization. c) Deletion of RNAi components enhances both methylation of histone H3K9 and heterochromatization. d) Mutation of RNAi components denatures both methylation of histone H3K9 and heterochromatization.

Answer: a Difficulty: Medium Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

31) What is the advantage of the highly condensed state of the DNA of mitotic chromosomes? a) This state allows gene expression needed during mitosis. b) The highly condensed state favors delivery of an intact package of DNA to each daughter cell. c) The condensed state allows chromosomes to fuse more easily.

d) The condensed state allows replication to occur more rapidly as the cell enters mitosis. e) The condensed state favors DNA repair prior to mitosis.

Answer: b Difficulty: Medium Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

32) Scientists can stain chromosomes from mitotic cells and photograph the chromosomes using a microscope. Each chromosome can then be cut out of the photograph, the chromosomes matched up in homologous pairs and placed in order of decreasing size. This methodcan be used to screen individuals for chromosomal abnormalities, like extra, missing or grossly altered chromosomes. What is such a picture called? a) karyoplan b) eukaryote c) karyotype d) karyokinesis e) prokaryote Answer: c Difficulty: Easy Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

33) A stretch of repeated sequences at the tip of a DNA molecule forming a cap at the end of the chromosome is called a ________. a) telomere b) chromomere c) centromere d) telophase e) karyomere Answer: a Difficulty: Easy

Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

34) If cells cannot replicate the ends of their DNA, what should happen with each round of cell division? a) The chromosomes should stay exactly the same length. b) The chromosomes should get longer. c) The mitotic spindle should shrink. d) The chromosomes should get shorter. e) The chromosomes should denature.

Answer: d Difficulty: Medium Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

35) The fact that chromosomes should become shorter and shorter with each round of cell division is referred to as the ________. a) shortening contradiction b) the replication paradox c) the short end hypothesis d) the truncated end problem e) the end-replication problem Answer: e Difficulty: Medium Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

36) In a rare disease, individuals suffer from bone marrow failure due to the inability of this blood-forming tissue to produce a sufficient number of blood cells over a human lifetime. What is NOT a cause of this condition?

a) Individuals have greatly elevated telomerase levels. b) Individuals have greatly reduced telomerase levels. c) Individuals are heterozygous for the gene that encodes the telomerase RNA. d) Individuals are heterozygous for the gene that encodes the telomerase protein subunit.

Answer: a Difficulty: Hard Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

37) Why was it initially expected that cloned animals might have a shorter life span? a) The chromosomes of the donor nuclei had shortened telomeres. b) The chromosomes of the donor nuclei had lengthened telomeres. c) The egg cell had elevated telomerase. d) The donor cell had elevated telomerase. e) After transplant of the nucleus, telomerase levels climbed precipitously.

Answer: a Difficulty: Hard Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

38) Which is NOT an example of an epigenetic phenomenon? a) X chromosome inactivation b) histone methylation patterns c) sequence of distal promoter elements d) localization of histone variant CENP-A e) covalent modification of DNA Answer: c Difficulty: Medium Learning Objective: LO 12.4 Compare the packaging of genetic material into mitotic and nonmitotic chromosomes.

Section Reference: Section 12.4 Chromosomes and Chromatin

39) Which of the following would be the most acceptable explanation for why cloned animals actually have telomeres of normal length on their chromosomes? a) The telomeres were elongated before transfer to the egg by telomerase in egg cell cytoplasm. b) The telomeres were elongated after transfer to the egg by telomerase in egg cell cytoplasm. c) The telomeres were shortened before transfer to the egg by telomerase in egg cell cytoplasm. d) The telomeres were shortened after transfer to the egg by telomerase in egg cell cytoplasm. e) The telomeres were replaced prior to mitosis by DNA repair.

Answer: b Difficulty: Hard Learning Objective: LO 12.5 Outline the evidence demonstrating that the nucleus is an ordered organelle.

Section Reference: Section 12.5 The Nucleus as an Organized Organelle

40) Genes are physically moved to sites within the nucleus called _________, where the transcription machinery is concentrated and within which genes involved in the same response tend to become colocalized. a) transcription homes b) transcription sites c) transcription factories d) translation factories e) nucleosynthetic locales Answer: c Difficulty: Easy Learning Objective: LO 12.5 Outline the evidence demonstrating that the nucleus is an ordered organelle.

Section Reference: Section 12.5 The Nucleus as an Organized Organelle

41) Which of the following is NOT a general description of one of the gene expression regulation mechanisms that operate in eukaryotic organisms? a) transcriptional-level controls b) processing-level controls c) translational-level controls d) replication-level controls

e) post-translational-level controls Answer: d Difficulty: Medium Learning Objective: LO 12.6 List four levels of regulation of gene expression in eukaryotic cells.

Section Reference: Section 12.6 An Overview of Gene Regulation in Eukaryotes

42) Which level of control of gene expression is defined as determining if a particular gene can give rise to mRNA and, if so, how often? a) transcriptional-level controls b) processing-level controls c) translational-level controls d) replication-level controls e) post-translational-level controls Answer: a Difficulty: Easy Learning Objective: LO 12.6 List four levels of regulation of gene expression in eukaryotic cells.

Section Reference: Section 12.6 An Overview of Gene Regulation in Eukaryotes

43) What level of control of gene expression is defined as regulating whether or not a particular mRNA is actually used in protein synthesis and, if so, how long and for how long a period of time? a) transcriptional-level controls b) processing-level controls c) translational-level controls d) replication-level controls e) post-translational-level controls Answer: c Difficulty: Easy Learning Objective: LO 12.6 List four levels of regulation of gene expression in eukaryotic cells.

Section Reference: Section 12.6 An Overview of Gene Regulation in Eukaryotes

44) The success of cloning experiments led to all of the following conclusions EXCEPT:

a) the transcriptional state of a differentiated cell is reversible b) the transcriptional state chromatin in a differentiated cell is irreversible c) the transcriptional state chromatin in a differentiated cell is reversible d) a nucleus from a differentiated cell can be reprogrammed by factors residing in the cytoplasm of its new environment Answer: b Difficulty: Medium Learning Objective: LO 12.6 List four levels of regulation of gene expression in eukaryotic cells.

Section Reference: Section 12.6 An Overview of Gene Regulation in Eukaryotes

45) You are interpreting data on a DNA chip or microarray. You expose the chip to a mixture of two cDNA populations: one from cells that were not treated with a glucocorticoid hormone (untreated controls; labeled with a red fluorescent dye) and a population from cells that were treated with glucocorticoid hormones (glucocorticoid-treated; labeled with green fluorescent dye). You look at a spot on the chip representing the gene for phosphofructokinase, a gene that is not affected by glucocorticoid treatment, but is instead expressed in all cells. What color should the spot representing the phosphofructokinase gene be? a) red b) green c) yellow d) no color, the spot is not labeled e) brown Answer: c Difficulty: Hard Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

46) You are interpreting data on a DNA chip or microarray. You expose the chip to a mixture of two cDNA populations: one from cells that were not treated with a glucocorticoid hormone (untreated controls; labeled with a red fluorescent dye) and a population from cells that were treated with glucocorticoid hormones (glucocorticoid-treated; labeled with green fluorescent dye). You look at a spot on the chip representing the gene for phosphoenolase, a gene that is turned off by glucocorticoid treatment, but is expressed in control, untreated cells. What color should the spot representing the phosphoenolase gene be?

a) red b) green c) yellow d) no color, the spot is not labeled e) brown Answer: a Difficulty: Hard Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

47) Which type of molecule binds at the core promoter sites in association with RNA polymerase? a) general transcription factors b) sequence-specific transcription factors c) elongation factors d) initiation factors e) termination factors Answer: a Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

48) The extent to which a given gene is transcribed presumably depends upon __________. a) the single transcription factor bound to its upstream regulatory elements b) the particular combination of transcription factors bound to its upstream regulatory elements c) the particular combination of transcription factors bound to its downstream regulatory elements d) the combination of initiation factors bound to its upstream regulatory elements e) the combination of translational factors bound to its upstream regulatory elements Answer: b Difficulty: Easy

Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

49) Which of the following is NOT a transcription factor identified as important for maintaining pluripotency in embryonic stem (ES) cells? a) Oct4 b) Myc c) Cal5 d) Sox2 e) Klf4 Answer: c Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

50) Each transcription factor usually has at least two domains that mediate different aspects of their function. What are they? a) the DNA-binding domain and the activation domain b) the activation domain and the repression domain c) the DNA-binding domain and the repression domain d) the RNA-binding domain and the activation domain e) the RNA-binding domain and the repression domain Answer: a Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

51) What domain of a transcription factor is responsible for recognizing and associating with specific DNA base pair sequences? a) the DNA-binding domain

b) the activation domain c) the repression domain d) the DNA-unwinding domain e) the DNA-derepression domain Answer: a Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

52) Which transcription factor helps to activate genes needed for cell division? a) Egr b) Csn c) GATA d) trp Answer: a Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

53) The helix-loop-helix (HLH) motif is often preceded by a stretch of highly ______ amino acids whose ______ charged side chains contact DNA and determine the transcription factor's sequence specificity. a) basic, positively b) basic, negatively c) acidic, negatively d) acidic, positively e) hydrophobic, neutral Answer: a Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

54) What phenomenon greatly expands the diversity of regulatory factors that can be generated from a limited number of polypeptides? a) heterodimerization b) homodimerization c) heterohomodimerization d) recombination e) heterotrimerization Answer: a Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

55) The combination of a basic stretch of amino acids and a leucine zipper is known as a(n) _____ motif. a) bHLH b) bZIP c) acidic zipper d) basic zipper e) basido zipper Answer: b Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

56) The α-helical portions of the bZIP proteins ______. a) facilitate dimerization b) allow the protein to recognize a specific nucleotide sequence in DNA c) prevent dimerization d) allow the protein to recognize a specific nucleotide sequence in RNA e) facilitate tetramerization

Answer: a Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

57) The basic amino acid stretch in bZIP proteins _______. a) facilitates dimerization b) allows the protein to recognize a specific nucleotide sequence in DNA c) prevents dimerization d) allows the protein to recognize a specific nucleotide sequence in RNA e) facilitates tetramerization Answer: b Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

58) When present, the TATA, CAAT and GC boxes are typically found within 100 – 150 bp upstream from the transcription start site. Due to their closeness to the start of gene, they are often called ______. a) distal promoter elements b) proximal promoter elements c) central promoter sites d) primary promoter elements e) primary promoter sites Answer: b Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

59) You attempt deletion mapping of a part of the promoter region of a particular gene. You remove a short sequence of nucleotides. Once the altered DNA is transfected into cells, the cells are able to transcribe the transfected DNA in a normal fashion. What do you conclude? a) The sequence that was removed is an essential part of the promoter. b) The sequence that was deleted is an important determinant of the ability to transcribe the gene. c) The sequence that was removed is not an essential part of the promoter. d) The deleted sequence has a moderate level of importance in promoting transcription. e) The deleted sequence binds tightly to RNA polymerase.

Answer: c Difficulty: Hard Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

60) What strategy in transcription factor research allows the simultaneous monitoring of all sites in the genome that carry out a particular activity with the goal of identifying all of the sites bound by a given transcription factor under a given set of physiological conditions? a) deletion mapping b) DNA footprinting c) genome-wide location analysis d) FISH e) scanning electron microscopy Answer: c Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

61) Treatment of fragmented DNA with a particular transcription factor attached at a number of sites with antibodies against that transcription factor can permit _________. a) precipitation of DNA fragments bound to that transcription factor b) solubilization of DNA fragments bound to that transcription factor c) hydrolysis of DNA fragments bound to that transcription factor d) hydrolysis of DNA fragments that remain unbound by that transcription factor e) precipitation of DNA fragments not bound to that transcription factor

Answer: a Difficulty: Hard Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

62) When DNA-binding proteins are removed from immunoprecipitated DNA sequences and the DNA fragments precipitated by the antibody are subsequently sequenced directly to determine the genomic sites bound, the technique is called __________. a) Hip-chip b) ChIP-chip c) ChIP-seq d) chromatin immunoprecipitation e) ChIP Answer: c Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

63) Transcription factors bound at the enhancer stimulate the initiation of transcription at the core promoter through the action of intermediaries called _____. a) corepressors b) cotranscriptors c) coactivators d) preinitiators e) costimulators Answer: c Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

64) Evidence suggests that ________ of __________ groups from nucleosomes in the wake of an elongating RNA polymerase prevents inappropriate __________ within the internal coding region of a gene. a) addition, acetyl, initiation of transcription b) removal, acetyl, initiation of translation c) removal, acetyl, initiation of transcription d) removal, methyl, initiation of transcription e) addition, methyl, initiation of translation Answer: c Difficulty: Hard Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

65) The ChIP technique designed to detect genome-wide histone modifications has been developed to detect histone modifications in all of the following EXCEPT: a) H3K9 b) H4K16 c) H3K4 d) H3K36 e) H4K15 Answer: e Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

66) The enzymes that remove acetyl groups from histones in the chromatin are ________. a) histone acetyltransferases b) histone deacetylases c) histone acetylases d) histone methylases e) methylacetyltransferases

Answer: b Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

67) In gene expression profiling by microarray analysis, ____ sequences produced from mRNA are hybridized with ____ sequences that have been spotted onto a glass slide. a) cDNA, complementary RNA b) cDNA, complementary DNA c) RNA, complementary d) intron, exon e) short, long Answer: b Difficulty: Easy Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

68) A plant breeder is looking to create a novel bloom type highlighting the intricate colors found in the carpals of a particular lily by reducing the stamens. He is not concerned about plant fertility. What would be his most efficient way to produce new candidate plants? a) mutate Gene A b) mutate Gene B c) mutate Gene C d) mutate Gene A and B e) mutate Gene B and C Answer: c Difficulty: Hard Learning Objective: LO 12.8 Explain the role of MADS domain transcription factors in the ABC model of floral mutations.

Section Reference: Section 12.8 Green Cells: The ABC model and MADS domain transcription factors

69) How do the proteins involved in controlling transcription of genes related to flower development associate with one another? a) in homodimeric complexes of proteins sharing a common MADS domain b) in heterotetrameric complexes of proteins sharing a common MADS domain c) in heterotetrameric complexes of proteins sharing a common MARS domain d) in homotrimeric complexes of proteins sharing a common MARS domain Answer: b Difficulty: Medium Learning Objective: LO 12.8 Explain the role of MADS domain transcription factors in the ABC model of floral mutations.

Section Reference: Section 12.8 Green Cells: The ABC model and MADS domain transcription factors

70) If an exon excised, what other RNA sequences will it be excised with it? a) the flanking exons b) the flanking introns c) one flanking exon and one flanking intron d) the promoter e) the poly(A) sequence Answer: b Difficulty: Hard Learning Objective: LO 12.9 Explain how alternative splicing and RNA editing can increase the number of proteins produced by the genome.

Section Reference: Section 12.9 RNA Processing Control

71) Which genetic phenomenon below involves the conversion of specific nucleotides to other nucleotides after RNA has been transcribed? a) translational frameshifting b) termination codon readthrough c) mRNA editing d) alternative translation initiation e) translational bypassing

Answer: c Difficulty: Easy Learning Objective: LO 12.9 Explain how alternative splicing and RNA editing can increase the number of proteins produced by the genome.

Section Reference: Section 12.9 RNA Processing Control

72) Messenger RNA editing is an example of gene expression at the _________ level. a) transcriptional b) translational c) posttranslational d) posttranscriptional e) pretranscriptional Answer: d Difficulty: Easy Learning Objective: LO 12.9 Explain how alternative splicing and RNA editing can increase the number of proteins produced by the genome.

Section Reference: Section 12.9 RNA Processing Control

73) When an adenine (A) is converted to an inosine (I), how is it subsequently read by the translational machinery? a) It is read as a guanine (G). b) It is read as a cytosine (C). c) It is read as a uracil (U). d) It is read as a thymine (T).

Answer: a Difficulty: Easy Learning Objective: LO 12.9 Explain how alternative splicing and RNA editing can increase the number of proteins produced by the genome.

Section Reference: Section 12.9 RNA Processing Control

74) Which is NOT an effect mRNA editing may have on a newly transcribed mRNA? a) It can create new splice sites.

b) It can generate new start codons. c) It can generate stop codons. d) It can lead to amino acid substitutions.

Answer: b Difficulty: Medium Learning Objective: LO 12.9 Explain how alternative splicing and RNA editing can increase the number of proteins produced by the genome.

Section Reference: Section 12.9 RNA Processing Control

75) In mRNA editing, to which nitrogenous bases is adenine converted by the enzymatic removal of an amino group? a) cytosine b) inosine c) guanine d) thymine e) uracil Answer: b Difficulty: Easy Learning Objective: LO 12.9 Explain how alternative splicing and RNA editing can increase the number of proteins produced by the genome.

Section Reference: Section 12.9 RNA Processing Control

76) What extends from the methylguanosine cap at the start of an mRNA to the AUG initiation codon? a) the first intron b) the last exon c) the 5' UTR d) the 3' UTR e) the last intron Answer: c Difficulty: Easy Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

77) What extends from the termination codon at the end of an mRNA coding region to the end of the poly(A) tail? a) the first intron b) the last exon c) the 5' UTR d) the 3' UTR e) the last intron Answer: d Difficulty: Easy Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

78) _______ mRNAs are preferentially localized at the anterior end of a fruit fly oocyte; ______ mRNAs are preferentially localized at the opposite or posterior end of the oocyte. a) Bicoid, oskar b) Oskar, bicoid c) Bicoid, staufen d) Staufen, bicoid e) Oskar, staufen Answer: a Difficulty: Medium Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

79) The oskar protein is required for the ________, which develop at the _______ end of the Drosophila larva. a) formation of germ cells, anterior b) formation of germ cells, posterior c) formation of muscle cells, anterior d) formation of osteocytes, posterior

e) formation of brain cells, anterior Answer: b Difficulty: Medium Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

80) Why might localizing mRNAs in the oocyte be more efficient than localizing the proteins they encode? a) Each mRNA can be translated into a limited number of proteins. b) Each mRNA can be translated into a large number of proteins. c) Messenger RNAs are easier to immobilize than proteins. d) Localizing proteins would denature them.

Answer: c Difficulty: Hard Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

81) The localization of mRNAs is mediated by specific proteins that recognize mRNA localization sequences on the mRNAs. Select the molecule or molecular region which is NOT believed to be involved in localization. a) 3’ UTR of mRNA b) collagen c) microtubules d) kinesin I motor protein e) microfilaments Answer: b Difficulty: Easy Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

82) What role are microfilaments thought to play in the localization of oskar and bicoid mRNAs in the fruit fly oocytes? a) They are thought to anchor mRNAs in position after they have arrived at their destination. b) They move these mRNAs to their final destination. c) They play no role in localization or anchoring the mRNAs in the proper position. d) They compress the mRNAs. e) They increase the stability of mRNAs. Answer: a Difficulty: Medium Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

83) Why does the activation of a protein kinase that acts on initiation factor eIF2 block protein synthesis? a) Phosphorylated eIF2 denatures. b) Phosphorylated eIF2 cannot exchange its GDP for GTP, which is required for eIF2 to participate in another round of translation initiation. c) Phosphorylated eIF2 cannot exchange its GTP for GDP, which is required for eIF2 to participate in another round of translation initiation. d) Phosphorylated eIF2 is hyperactivated, blocking further translation. e) Dephosphorylated eIF2 cannot exchange its GDP for GTP, which is required for eIF2 to participate in another round of translation initiation.

Answer: b Difficulty: Hard Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

84) The inactive mRNAs that are stored in an egg prior to fertilization typically have ________. a) lengthened 5' UTRs b) many bound inhibitory proteins c) extra long poly(A) tails d) many lipids associated with them

e) shortened 5' UTRs Answer: b Difficulty: Medium Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

85) The inactive mRNAs that are stored in an egg prior to fertilization typically have ________. a) lengthened 5' UTRs b) lengthened poly(A) tails c) shortened poly(A) tails d) many lipids associated with them e) shortened 5' UTRs Answer: c Difficulty: Medium Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

86) The normal length of a poly(A) tail is about how many adenosine residues? a) 100 b) 500 c) 200 d) 1000 e) 700 Answer: c Difficulty: Medium Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

87) How many adenosine residues must the poly(A) tail have to short enough to cause the mRNA to be degraded rapidly?

a) 1 b) about 10 c) about 100 d) about 30 e) about 75 Answer: d Difficulty: Easy Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

88) A complex of exonucleases that degrades mRNAs is called the ______. a) endosome b) execrosome c) exosome d) enterosome e) edusome Answer: c Difficulty: Easy Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

89) Deadenylation, decapping and 5' —> 3' degradation occurs within small, transient cytoplasmic granules called _________. a) P-granules b) P-coats c) decappers d) P-bodies e) degradators Answer: d Difficulty: Easy

Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

90) What may happen if a protein that is supposed to have a short survival time and that is involved in the initiation of cell division is not destroyed when it is supposed to be destroyed? a) The cell may die quickly. b) The cell may become malignant. c) The cell may become benign. d) The cell may stop dividing but survive. e) The cell may undergo apoptosis.

Answer: b Difficulty: Medium Learning Objective: LO 12.10 Describe three different ways in which gene expression might be controlled at the translational level.

Section Reference: Section 12.10 Translational Control

91) A specific internal sequence of amino acids that ensures that the protein containing it will not survive long within the cell is called a _______. a) degradicon b) degron c) proteolicron d) denocon e) codon Answer: b Difficulty: Easy Learning Objective: LO 12.11 Explain the role of proteasomes and ubiquitin in determining how long a functional protein remains in the cell.

Section Reference: Section 12.11 Posttranslational Control: Determining Protein Stability

92) Covalent linkage to what highly-conserved molecule marks proteins for destruction? a) chaperonin b) actin

c) polyubiquitin d) cyclin e) dystrophin Answer: c Difficulty: Easy Learning Objective: LO 12.11 Explain the role of proteasomes and ubiquitin in determining how long a functional protein remains in the cell.

Section Reference: Section 12.11 Posttranslational Control: Determining Protein Stability

93) What happens to membrane proteins that have been attached to a single ubiquitin molecule? a) They are selectively incorporated into endocytic vesicles. b) They move immediately to proteasomes. c) They stay in the membrane. d) They move to the rough endoplasmic reticulum. e) They move directly to the smooth endoplasmic reticulum.

Answer: a Difficulty: Medium Learning Objective: LO 12.11 Explain the role of proteasomes and ubiquitin in determining how long a functional protein remains in the cell.

Section Reference: Section 12.11 Posttranslational Control: Determining Protein Stability

94) What modification, targeting a protein for degradation, is usually recognized by the cap of a proteasome? a) proteins with a single ubiquitin b) naked proteins c) precipitated proteins d) polyubiquitinated proteins e) lysinated proteins Answer: d Difficulty: Easy Learning Objective: LO 12.11 Explain the role of proteasomes and ubiquitin in determining how long a functional protein remains in the cell.

Section Reference: Section 12.11 Posttranslational Control: Determining Protein Stability

95) To which amino acid is the first ubiquitin on a polyubiquitinated protein attached? a) glycine b) leucine c) arginine d) phenylalanine e) lysine Answer: e Difficulty: Easy Learning Objective: LO 12.11 Explain the role of proteasomes and ubiquitin in determining how long a functional protein remains in the cell.

Section Reference: Section 12.11 Posttranslational Control: Determining Protein Stability

Question Type: Multiple Select

96) When referring to cell metabolism and using digital logic analogies, which of the following statements is correct? (Select all correct choices) a) transcription of the lac operon is an example of an OR gate only, because both lactose and cAMP must always be present b) transcription of the lac operon is an example of an OR gate only because either lactose OR cAMP must always be present c) transcription of the lac operon is an example of an AND or OR gate because differences in the lactose concentration can lead to different transcriptional switch behaviors d) transcription of the lac operon is an example of an AND or OR gate because differences in the cAMP concentration can lead to different transcriptional switch behaviors e) transcription of the lac operon is an example of an AND gate only, because both lactose and cAMP must always be present Answer: c, d Difficulty: Hard Learning Objective: LO 12.2 Explain how gene regulatory mechanisms can be used to reprogram cell behavior.

Section Reference: Section 12.2 Engineering Linkage: Building Digital Logic with Genes

Question Type: Multiple Select

97) During a cloning experiment, the nucleus of a differentiated cell ________. (Select all correct choices) a) is able to stop expressing the genes of the adult tissue from which it is taken b) starts expressing the genes of the adult tissue from which it was taken after transplantation c) begins to selectively express the genes that are appropriate for the activated egg in which it suddenly finds itself d) begins to selectively express the genes that are appropriate for the adult tissue in which it suddenly finds itself Answer: a, c Difficulty: Medium Learning Objective: LO 12.6 List four levels of regulation of gene expression in eukaryotic cells.

Section Reference: Section 12.6 An Overview of Gene Regulation in Eukaryotes

Question Type: Multiple Select

98) You are working with adult mouse fibroblast cells. The genes for transcription factors from pluripotent stem cells are transduced into the adult fibroblast cells as part of viral vectors in various combinations, and once inside the cells they are expressed. What results would you expect to obtain? (Select all correct choices) a) The fibroblasts die. b) A combination of transduced genes for only four specific transcription factors is sufficient to reprogram the fibroblasts into undifferentiated cells. c) A combination of transduced genes for only four specific transcription factors is sufficient to cause the fibroblasts to behave like pluripotent ES cells. d) A combination of transduced genes for only four specific transcription factors is sufficient to cause a terminal differentiation of the fibroblast cells.

Answer: b, c Difficulty: Hard Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

Question Type: Multiple Select

99) You are working with adult mouse fibroblast cells. The genes for transcription factors from pluripotent stem cells are transduced into the adult fibroblast cells as part of viral vectors in various combinations, and once inside the cells they are expressed. Cells are produced that are capable of dividing indefinitely in culture and of differentiating into all of the various types of the body's cells. What are these new cells called? (Select all correct choices) a) iPS cells b) white blood cells c) induced pluripotent cells d) infracted pluripotent cells e) infant-derived pluripotent cells Answer: a, c Difficulty: Easy Learning Objective: LO 12.7 Explain the relationship between transcriptional control and epigenetic changes.

Section Reference: Section 12.7 Transcriptional Control

Question Type: Multiple Select

100) In flowering plants, which gene group(s) are needed for petal formation? (Select all correct choices) a) class A genes b) class B genes c) class C genes d) none are required Answer: a, b Difficulty: Medium Learning Objective: LO 12.8 Explain the role of MADS domain transcription factors in the ABC model of floral mutations.

Section Reference: Section 12.8 Green Cells: The ABC model and MADS domain transcription factors

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 13

Question Type: Multiple Choice

1) Who was the first to suggest semiconservative replication? a) Meselson and Stahl b) Hershey and Chase c) Watson and Crick d) Avery, McCarty and MacLeod e) Darwin and Wallace Answer: c Difficulty: Easy Learning Objective: LO 13.1 Explain the concept of semiconservative DNA replication.

Section Reference: Section 13.1 DNA Replication

2) Which type of replication results in 2 duplexes made of one parental strand and one newly synthesized strand? a) semiconservative replication b) conservative replication c) dispersive replication d) incisive replication e) reservative replication Answer: a Difficulty: Medium Learning Objective: LO 13.1 Explain the concept of semiconservative DNA replication.

Section Reference: Section 13.1 DNA Replication

3) What theory of replication results in the integrity of both parental strands being disrupted, the new duplex strands made of both old and new DNA and neither the parental strands nor the parental duplex preserved?

a) semiconservative replication b) conservative replication c) dispersive replication d) incisive replication e) reservative replication Answer: c Difficulty: Medium Learning Objective: LO 13.1 Explain the concept of semiconservative DNA replication.

Section Reference: Section 13.1 DNA Replication

4) Bacteria are grown in a medium containing [15N]H4Cl for a number of generations so that all of the DNA is made of fully ‘heavy’ DNA. The bacteria are moved to a new medium and grown in [14N]H4Cl so that all subsequent new DNA will be ‘light.’ After one generation time, what does the DNA look like? a) All of the DNA is made of two ‘light’ strands. b) All of the DNA is made of two ‘heavy’ strands. c) All of the DNA is made of one ‘heavy’ strand and one ‘light’ strand. d) Each strand is made of a mixture of ‘heavy’ and ‘light’ DNA, with each strand being between 75% and 100% ‘light.’ e) Half of the DNA is made of two ‘light’ strands and half is made of two ‘heavy’ strands.

Answer: c Difficulty: Hard Learning Objective: LO 13.1 Explain the concept of semiconservative DNA replication.

Section Reference: Section 13.1 DNA Replication

5) Bacteria are grown in a medium containing [15N]H4Cl for a number of generations so that all of the DNA is made of fully ‘heavy’ DNA. The bacteria are moved to a new medium and grown in [14N]H4Cl so that all subsequent new DNA will be “light”. If replication were conservative, what would the DNA look like after TWO generation times have passed? a) All of the DNA is made of two ‘light’ strands. b) Half of the DNA is made of two ‘light’ strands and half is made of one ‘light’ strand and one ‘heavy’ strand. c) All of the DNA is made of one ‘heavy’ strand and one ‘light’ strand. d) Each strand is made of a mixture of ‘heavy’ and ‘light’ DNA with each strand being between 75% and 100% ‘light.’

e) Three quarters of the DNA is made of two ‘light’ strands and one quarter is made of 2 ‘heavy’ strands.

Answer: e Difficulty: Hard Learning Objective: LO 13.1 Explain the concept of semiconservative DNA replication.

Section Reference: Section 13.1 DNA Replication

6) Bacteria are grown in a medium containing [15N]H4Cl for a number of generations so that all of the DNA is made of fully ‘heavy’ DNA. The bacteria are moved to a new medium and grown in [14N]H4Cl so that all subsequent new DNA will be ‘light.’ If replication were dispersive, what would the DNA look like after TWO generation times? a) All of the DNA is made of two ‘light’ strands. b) Half of the DNA is made of two ‘light’ strands and half of the DNA is made of one ‘light’ strand and one ‘heavy’ strand. c) All of the DNA is made of one ‘heavy’ strand and one ‘light’ strand. d) Each strand is made of a mixture of ‘heavy’ and ‘light’ DNA, with each strand being between 75% and 100% ‘light.’ e) Three quarters of the DNA is made of two ‘light’ strands and one quarter is made of two ‘heavy’ strands.

Answer: d Difficulty: Hard Learning Objective: LO 13.1 Explain the concept of semiconservative DNA replication.

Section Reference: Section 13.1 DNA Replication

7) Cultured mammalian cells grown in thymidine for many generations were allowed to undergo replication in the presence of bromodeoxyuridine (BrdU), which replaces thymidine in DNA. After ONE round of replication, what does the DNA look like? a) All chromatids have one strand that contains BrdU and one strand that contains thymidine. b) All chromatids have two strands that contain BrdU. c) Half of the chromatids have two strands that contain BrdU and half have two strands lacking BrdU. d) Both of the strands of each chromatid contain mixtures of BrdU and thymidine. e) All chromatids lack BrdU. Answer: a

Difficulty: Hard Learning Objective: LO 13.1 Explain the concept of semiconservative DNA replication.

Section Reference: Section 13.1 DNA Replication

8) Cultured mammalian cells grown in thymidine for many generations were allowed to undergo replication in the presence of bromodeoxyuridine (BrdU), which replaces thymidine in DNA. After two rounds of replication, what does the DNA look like? a) All chromatids have one strand that contains BrdU and one strand that does not. b) All chromatids have two strands that contain BrdU. c) Half of the chromatids have two strands that contain BrdU and half have two strands lacking BrdU. d) Both strands of each chromatid contain mixtures of BrdU and thymidine. e) Half of the chromatids have two strands that contain BrdU and half have one strand lacking BrdU and one strand containing BrdU. Answer: e Difficulty: Hard Learning Objective: LO 13.1 Explain the concept of semiconservative DNA replication.

Section Reference: Section 13.1 DNA Replication

9) Cultured mammalian cells grown in thymidine for many generations were allowed to undergo replication in the presence of bromodeoxyuridine (BrdU), which replaces thymidine in DNA. After two rounds of replication, what would the DNA look like if replication were conservative? a) All chromatids have one strand that contains BrdU and one strand that does not. b) All chromatids have two strands that contain BrdU. c) Half of the chromatids have two strands that contain BrdU and half have two strands lacking BrdU. d) Both strands of each chromatid contain mixtures of BrdU and thymidine. e) Three quarters of the chromatids have two strands that contain BrdU and one quarter have two strands lacking BrdU. Answer: e Difficulty: Hard Learning Objective: LO 13.1 Explain the concept of semiconservative DNA replication.

Section Reference: Section 13.1 DNA Replication

10) Cultured mammalian cells grown in thymidine for many generations were allowed to undergo replication in the presence of bromodeoxyuridine (BrdU), which replaces thymidine in DNA. After one round of replication, what would the DNA look like if replication were dispersive? a) All chromatids have one strand that contains BrdU and one strand that does not. b) All chromatids have two strands that contain BrdU. c) Half of the chromatids have two strands that contain BrdU and half have two strands lacking BrdU. d) Both strands of each chromatid contain mixtures of BrdU and thymidine. e) All chromatids lack BrdU. Answer: d Difficulty: Hard Learning Objective: LO 13.1 Explain the concept of semiconservative DNA replication.

Section Reference: Section 13.1 DNA Replication

11) The specific site on the bacterial chromosome at which replication begins is called the ________ of replication. a) beginning b) origin c) initiation site d) initiator e) replicon Answer: b Difficulty: Easy Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

12) Replication moves outward from the origin of replication in ________ direction(s) and is said to be ________. a) both, unidirectional b) both, bidirectional c) one, bidirectional d) unique, unidirectional e) one, unidirectional

Answer: b Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

13) In replicating bacterial chromosomes, where does replication terminate? a) at the origin b) across the circular chromosome from the origin c) at random locations around the circle d) one quarter of the way around the DNA circle from the origin Answer: b Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

14) What happens to DNA (circular DNA or linear DNA that is not free to rotate) when it becomes overwound? a) It becomes negatively supercoiled. b) It breaks into a number of fragments. c) It becomes positively supercoiled. d) It stretches. e) Its mass decreases.

Answer: c Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

15) The replication fork generates _______ supercoils in the _______ portion of the DNA molecule. a) negative, replicated b) positive, replicated c) neutral, unreplicated

d) positive, unreplicated e) negative, unreplicated Answer: d Difficulty: Hard Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

16) Where is DNA gyrase normally positioned as it changes positively supercoiled DNA into negatively supercoiled DNA in the replicating circular, bacterial chromosome? a) It is permanently located at the origin. b) It travels along the DNA behind the replication fork. c) It travels along the DNA ahead of the replication fork. d) It travels along the DNA at the replication fork as part of the replisome. e) It is permanently located at the termination site of replication.

Answer: c Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

17) What supplies the energy that drives the relief of mechanical strain by DNA gyrase? a) condensation of ATP b) condensation of GTP c) hydrolysis of ATP d) hydrolysis of GTP e) a proton gradient Answer: c Difficulty: Easy Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

18) Who was the first to purify an enzyme that could incorporate DNA precursors into a polymer?

a) Arthur Kornberg b) James Watson c) Francis Crick d) Jacques Monod Answer: a Difficulty: Easy Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

19) In early experiments with DNA polymerase I, what evidence convinced investigators that the original unlabeled DNA in the reaction mixture served as the template for the newly made DNA? a) The new DNA had the same base composition as the original unlabeled DNA. b) The new DNA had a variable base composition. c) The new DNA had a triple helix. d) The new DNA and the old DNA were made of the same elements. e) The new DNA was equally stable.

Answer: a Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

20) Which of the following DNA molecules could serve as an effective template for DNA synthesis in the early studies of DNA polymerase activity? a) linear single-stranded DNA b) circular single-stranded DNA c) partially double-stranded DNA d) linear single-stranded RNA Answer: c Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

21) Why is an intact, linear double helix an ineffective template for DNA polymerase? a) It has a 3'-hydroxyl terminus, but lacks a template. b) It lacks a 3'-hydroxyl group, but has a template. c) It lacks a 3'-hydroxyl group and a template. d) It has a 3'-hydroxyl group and has a template. e) It lacks a 5'-hydroxyl group and has a template.

Answer: a Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

22) Why is a single-stranded, circular DNA an ineffective template for DNA polymerase? a) It has a 3'-hydroxyl terminus, but lacks a template. b) It lacks a 3'-hydroxyl primer, but has a template. c) It lacks a 3'-hydroxyl group and a template. d) It has a 3'-hydroxyl group and has a template. e) It lacks a 5'-hydroxyl group and has a template.

Answer: b Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

23) What discovery suggested the presence of other DNA polymerases in bacteria besides the Kornberg DNA polymerase enzyme? a) Kornberg DNA polymerase mutants died. b) Kornberg DNA polymerase mutants grew much more slowly. c) Mutants with <1% of the normal Kornberg DNA polymerase enzyme activity multiplied at a normal rate. d) Mutants with <1% of the normal Kornberg DNA polymerase enzyme activity multiplied at a low rate. e) Kornberg DNA polymerase mutants reproduced much faster than normal bacteria.

Answer: c

Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

24) All DNA polymerases lay down nucleotides in a ______ direction and move along the template in a _______ direction. a) 3'—>5', 5'—>3' b) N—>C, C—>N c) 5'—>3', 3'—>5' d) C—>N, N—>C e) N—>C, 5'—>3' Answer: c Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

25) The DNA strand growing toward the replication fork grows ______ in a 5'—>3' direction as the replication fork advances and is called the ________. a) continuously, leading strand b) discontinuously, lagging strand c) continuously, lagging strand d) discontinuously, leading strand e) steadfastly, forthright strand Answer: a Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

26) The _______ strand fragment grows away from the replication fork toward the ___ of the previously synthesized fragment to which it is subsequently linked. a) leading, 5'-end b) lagging, 5'-end

c) leading, 3'-end d) lagging, 3'-end e) lagging, N-terminal Answer: b Difficulty: Hard Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

27) Since one strand of DNA is synthesized continuously during replication and the other is made discontinuously, replication is said to be ___________. a) continuous b) hemicontinuous c) discontinuous d) semidiscontinuous e) semicontinuous Answer: d Difficulty: Easy Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

28) During replication of the lagging strand, DNA is constructed in small segments called ________ that are rapidly linked to longer pieces of DNA synthesized earlier. a) Watson fragments b) Tokyo fragments c) Osaka fragments d) Okazaki fragments e) Ouabain fragments Answer: d Difficulty: Easy Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

29) The enzyme that joins the small fragments of the lagging strand together into a continuous strand is called _______. a) DNA gyrase b) DNA ligase c) DNA polymerase d) primase e) deoxyribonuclease Answer: b Difficulty: Easy Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

30) Strand initiation during replication is carried out by an enzyme that makes a short RNA molecule that is used as a primer; the enzyme is a distinct type of RNA polymerase, called _______. a) RNA gyrase b) RNA ligase c) ribonuclease d) primase e) deoxyribonuclease Answer: d Difficulty: Easy Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

31) What happens to the RNA primers that initiate replication? a) They are chemically altered to DNA. b) They are sealed into the DNA molecule with ligase. c) They are excised along with the complementary DNA. d) They are removed and replaced with DNA. Answer: d Difficulty: Hard Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

32) Which of the following is an advantage of using RNA primers during initiation of a strand in replication? a) Using primers may decrease mistakes; such errors as mismatched bases are more likely during initiation than elongation, and the use of a short, removable RNA segment avoids inclusion of mismatched bases. b) Using primers slows down the process of replication, which increases accuracy of complementary base pairing. c) The RNA of the primers is more stable. d) The RNA of the primers is more likely to lead to changes in base sequence, which enhances the rate of mutation and thus evolution. e) The RNA of the primers allows more efficient packing of the chromosomes after its removal.

Answer: a Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

33) _________ are DNA unwinding enzymes that unwind the DNA in a reaction using the energy from ________ to move along one of the DNA strands, breaking the _______ holding the two strands together. a) DNA helicases, ATP dehydration, disulfide linkages b) DNA gyrases, ATP hydrolysis, hydrogen bonds c) DNA helicases, ATP hydrolysis, 3'-5'-phosphodiester linkages d) DNA helicases, ATP hydrolysis, hydrogen bonds e) DNA gyrases, ATP dehydration, hydrogen bonds Answer: d Difficulty: Hard Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

34) Where is the DnaB helicase first loaded onto the DNA? a) at the replication terminator site

b) at the replication origin c) at random locations through the circular chromosome d) at the operator e) at the promoter Answer: b Difficulty: Easy Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

35) What proteins bind selectively to single-stranded DNA and are responsible for keeping it extended and preventing it from being rewound? a) DNA helicase b) DNA gyrase c) single-stranded DNA binding (SSB) proteins d) ATPase e) DNA unwindase Answer: c Difficulty: Easy Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

36) In bacteria, a _______ is formed when a ________ associates transiently with a _______. a) primosome, helicase, DNA polymerase b) primosome, helicase, primase c) ribosome, helicase, primase d) helicosome, primosome, DNA polymerase e) primosome, helicase, DNA ligase Answer: b Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

37) How does DNA polymerase III move from one site on the lagging strand template to a site closer to replication fork? a) It hitches a ride with the DNA polymerase that is moving that way along the leading strand template. b) It hitches a ride with the DNA polymerase that is moving that way along the lagging strand template. c) It moves by itself like a tiny molecular motor. d) It transports from the earlier Okazaki fragment to the later Okazaki fragment. e) It is moved toward the replication fork by a complex of proteins called the transportosome.

Answer: a Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

38) How can the replication of both DNA strands by two tethered polymerases be accomplished when the template strands run in opposite directions? a) One of the enzymes polymerizes DNA in the 3'—>5' direction. b) The DNA of the lagging strand loops back on itself so it has same orientation as the leading strand template. c) The DNA of the leading strand loops back on itself so it has same orientation as the lagging strand template. d) The lagging strand is broken and then rejoined regularly to allow simultaneous synthesis.

Answer: b Difficulty: Medium Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

39) As replication proceeds, the lagging strand template of the DNA is looped back on itself so that it has the same orientation as the leading strand template; the looping DNA repeatedly grows and shortens during lagging strand replication. This model is often referred to as the _________. a) telescope model b) extension model c) trombone model d) French horn model e) piccolo model

Answer: c Difficulty: Easy Learning Objective: LO 13.2 Outline the process of DNA replication in bacteria.

Section Reference: Section 13.2 DNA Replication in Bacterial Cells

40) Which DNA polymerase in bacteria is mostly involved in DNA repair to correct damaged DNA sections and removes RNA primers at the 5' ends of Okazaki fragments, replacing them with DNA? a) DNA polymerase I b) DNA polymerase II c) DNA polymerase III d) DNA polymerase IV Answer: a Difficulty: Easy Learning Objective: LO 13.3 Distinguish the functions of the various DNA polymerases.

Section Reference: Section 13.3 The Structure and Functions of DNA Polymerases

41) Which DNA polymerase in bacteria synthesizes DNA strands during replication and forms part of a complex that serves as a large replication machine? a) DNA polymerase I b) DNA polymerase II c) DNA polymerase III d) DNA polymerase IV Answer: c Difficulty: Easy Learning Objective: LO 13.3 Distinguish the functions of the various DNA polymerases.

Section Reference: Section 13.3 The Structure and Functions of DNA Polymerases

42) What is the name of the noncatalytic component of the DNA polymerase III holoenzyme that keeps the polymerase associated with the DNA template? a) β-pleated sheet

b) α-helix c) β-clamp d) α-clamp e) β-clam Answer: c Difficulty: Easy Learning Objective: LO 13.3 Distinguish the functions of the various DNA polymerases.

Section Reference: Section 13.3 The Structure and Functions of DNA Polymerases

43) The DNA polymerase on the leading strand template _____________. a) stays tethered to a single β clamp during replication b) switches from β clamp to β clamp during replication c) cycles to a new β clamp that has been assembled at an RNA primer-DNA template junction closer to the replication fork d) cycles to a new β clamp that has been assembled at an RNA primer-DNA template junction farther from the replication fork Answer: a Difficulty: Easy Learning Objective: LO 13.3 Distinguish the functions of the various DNA polymerases.

Section Reference: Section 13.3 The Structure and Functions of DNA Polymerases

44) The assembly of the β clamp around the DNA requires a multisubunit _______ that is also part of the ________; part of this structure opens the ______ so that it can fit around the DNA. a) clamp loader, polymericon, β clamp b) clamp loader, DNA polymerase III holoenzyme, β clamp c) DNA polymerase III holoenzyme, clamp loader, replicon d) β clamp, DNA polymerase III holoenzyme, clamp loader e) clamp loader, β clamp, DNA polymerase III holoenzyme Answer: b Difficulty: Hard Learning Objective: LO 13.3 Distinguish the functions of the various DNA polymerases.

Section Reference: Section 13.3 The Structure and Functions of DNA Polymerases

45) Why did Kornberg initially think that the exonuclease activity he found in his DNA polymerase preparations was a contaminating enzyme? a) The action of exonucleases is a lot like endonuclease. b) The action of exonucleases is so dramatically opposed to the activity of DNA polymerases, to synthesize DNA. c) The action of exonucleases is exactly like the action of DNA polymerase. d) Purification was so difficult. e) Enzymes can often run the reverse reactions.

Answer: b Difficulty: Easy Learning Objective: LO 13.3 Distinguish the functions of the various DNA polymerases.

Section Reference: Section 13.3 The Structure and Functions of DNA Polymerases

46) What is the function of the 5'—>3' exonuclease activity of DNA polymerase I? a) It removes mismatched nucleotides that have been incorporated by mistake. b) It replaces mismatched nucleotides with the correctly matched nucleotides. c) It removes the DNA primer laid down by the primase at the 5' end of the Okazaki fragment. d) It removes the RNA primer laid down by the primase at the 5' end of the Okazaki fragment. e) It nicks DNA to create a primer in the middle of a DNA chain.

Answer: d Difficulty: Medium Learning Objective: LO 13.3 Distinguish the functions of the various DNA polymerases.

Section Reference: Section 13.3 The Structure and Functions of DNA Polymerases

47) What happens simultaneously with the removal of RNA primer by the 5'—>3' exonuclease activity of DNA polymerase I? a) The DNA double helix is unwound. b) The gap left by the removal of the RNA primer is filled in with deoxyribonucleotides. c) The gap left by the removal of the RNA primer is filled in with ribonucleotides. d) DNA is supercoiled extensively.

Answer: b Difficulty: Medium Learning Objective: LO 13.3 Distinguish the functions of the various DNA polymerases.

Section Reference: Section 13.3 The Structure and Functions of DNA Polymerases

48) Which enzyme is responsible for joining the last deoxyribonucleotide added during RNA primer digestion to the 5' end of the previously synthesized and adjacent DNA fragment? a) DNA polymerase I b) DNA polymerase III c) DNA ligase d) the holoenzyme e) DNA gyrase Answer: c Difficulty: Easy Learning Objective: LO 13.3 Distinguish the functions of the various DNA polymerases.

Section Reference: Section 13.3 The Structure and Functions of DNA Polymerases

49) What is the probability that, in E. coli, an incorrect nucleotide will be incorporated into DNA during replication and remain there? a) one in one billion nucleotides b) one in 1000 nucleotides c) one in four million nucleotides d) one in 100,000 to 1,000,000 nucleotides e) one in 10,000 nucleotides Answer: a Difficulty: Easy Learning Objective: LO 13.3 Distinguish the functions of the various DNA polymerases.

Section Reference: Section 13.3 The Structure and Functions of DNA Polymerases

50) The prokaryotic enzyme DNA polymerase I can incorporate the wrong nucleotide occasionally. What is the probability that the wrong nucleotide is incorporated into the growing polynucleotide chain during replication? a) one in one billion nucleotides b) one in 1000 nucleotides c) one in four million nucleotides d) one in 100,000 to 1,000,000 nucleotides

e) one in 10,000 nucleotides Answer: d Difficulty: Medium Learning Objective: LO 13.3 Distinguish the functions of the various DNA polymerases.

Section Reference: Section 13.3 The Structure and Functions of DNA Polymerases

51) What is the average rate of DNA replication in a bacterium like E. coli? a) about 100 nucleotides/sec b) about 1,000 nucleotides/min c) about 1,000 nucleotides/sec d) about 10,000 nucleotides/sec e) about 100 nucleotides/min Answer: c Difficulty: Easy Learning Objective: LO 13.3 Distinguish the functions of the various DNA polymerases.

Section Reference: Section 13.3 The Structure and Functions of DNA Polymerases

52) What is the mechanism of action of the anti-HIV drug AZT? a) it causes double-strand DNA breaks b) it inhibits DNA synthesis by reverse transcriptase c) it prevents transcription in infected cells d) it blocks the active site of DNA ligase e) it prevents viral entry into cells Answer: b Difficulty: Easy Learning Objective: LO 13.4 Outline the process of DNA replication in viruses.

Section Reference: Section 13.4 Replication in Viruses

53) Which side chain critical to DNA strand elongation is lacking in the nucleotide analog azidothymidine (AZT)? a) the 5ʹ OH group

b) the 2ʹ OH group c) the 3ʹ OH group d) the triphosphate group Answer: c Difficulty: Medium Learning Objective: LO 13.4 Outline the process of DNA replication in viruses.

Section Reference: Section 13.4 Replication in Viruses

54) Theoretically, in the most efficient model of data storage, how many “bits” of information can be stored per nucleotide position when using DNA for data storage? a) 1 b) 2 c) 5 d) 10 Answer: b Difficulty: Easy Learning Objective: LO 13.5 Explain how DNA can be used to store data at the molecular level.

Section Reference: Section 13.5 Engineering Linkage: Storing Data in DNA

55) The small portions in which eukaryotic cells replicate their genomes are called _______. a) replicants b) replicons c) repliants d) replicosomes e) tracts Answer: b Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

56) What technique was used to show DNA molecules are replicated simultaneously at several sites along their length?

a) scanning electron microscopy b) confocal laser scanning microscopy c) autoradiographic analysis d) polyacrylamide gel electrophoresis e) isoelectric focusing Answer: c Difficulty: Medium Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

57) Which piece of evidence provided the best evidence that the sequence of DNA itself was unimportant in the timing of replication? a) The inactive, heterochromatized X chromosome in female mammals replicates late in S phase, while the active euchromatic X chromosome replicates at an earlier stage. b) The inactive, heterochromatized X chromosome in female mammals replicates early in S phase, while the active euchromatic X chromosome replicates at a later stage. c) The inactive, heterochromatized X chromosome in female mammals replicates late in M phase, while the active euchromatic X chromosome replicates at an earlier stage. d) Incorporation of radioactive DNA precursors in replicating cells begins over heterochromatic regions in the nucleus. e) Incorporation of radioactive DNA precursors in replicating cells ends over heterochromatic regions in the nucleus.

Answer: a Difficulty: Hard Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

58) What binds to the ORC to assemble the prereplication complex (pre-RC) that is competent to initiate replication? a) the ORC factors b) MCM proteins c) competence factors d) initiation factors e) enlisting factors

Answer: b Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

59) At what stage of the eukaryotic cell cycle do key protein kinases, like cyclin-dependent kinase, become activated to allow for DNA replication initiation? a) right after mitosis b) right before mitosis c) just before the start of S phase d) in the middle of the G2 phase e) in the G0 phase Answer: c Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

60) Cyclin-dependent kinase activity stays high through mitosis after rising prior to DNA synthesis. Which of the following results from its elevated activity? a) Chromosomes decondense. b) Formation of new prereplication complexes is suppressed. c) Formation of new prereplication complexes is enhanced. d) Histones are enlarged by removing their phosphate groups. e) Histones are shrunk by binding amino groups to them.

Answer: b Difficulty: Medium Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

61) Why does it appear that each origin can only be activated once per cell cycle? a) MCM proteins are displaced from the DNA after replication and cannot reassociate with a replication origin that has already fired.

b) The ORC is denatured after replication and cannot return to the DNA. c) The DNA becomes naked until the next round of cell division. d) MCM proteins reassociate with DNA immediately and prevent further replication from that DNA. e) MCM proteins bind to other proteins in the cytoplasm; together they actively inhibit further replication.

Answer: a Difficulty: Medium Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

62) The collection of proteins that forms the eukaryotic replicative complex is known as the __________. a) replicand b) replicon c) replisome d) replimere e) polymerizer Answer: c Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

63) Which eukaryotic DNA polymerase replicates mitochondrial DNA and does not appear to be involved in nuclear DNA replication? a) polymerase α b) polymerase β c) polymerase ɤ d) polymerase δ e) polymerase ε Answer: c Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

64) Which eukaryotic DNA polymerase functions in DNA repair, but does not appear to be involved in nuclear DNA replication? a) polymerase α b) polymerase β c) polymerase ɤ d) polymerase δ e) polymerase ε Answer: b Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

65) Which eukaryotic DNA polymerase is thought to be the primary DNA-synthesizing enzyme during replication of the lagging strand? a) polymerase α b) polymerase β c) polymerase ɤ d) polymerase δ e) polymerase ε Answer: d Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

66) Which eukaryotic DNA polymerase is thought to be the primary DNA-synthesizing enzyme during replication of the leading strand? a) polymerase α b) polymerase β c) polymerase ɤ d) polymerase δ e) polymerase ε

Answer: e Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

67) The clamp loader that loads PCNA onto DNA is called _______ and is analogous to the E. coli DNA polymerase III clamp loader complex. a) RFC b) KFC c) NBC d) TLC e) SEC Answer: a Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

68) What is responsible for removing the RNA primer and short DNA segment added by eukaryotic DNA polymerase δ? a) FEN-1 b) DNA polymerase α c) DNase H d) both FEN-1 and DNase H e) DNA ligase Answer: a Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

69) What is responsible for filling the gap left by the nucleases that digest the primer and the short DNA segment added to it by polymerase δ? a) DNA polymerase α

b) DNA polymerase δ c) DNA polymerase β d) both DNA polymerase α and DNA polymerase β e) RNase H1 Answer: b Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

70) What is responsible for joining eukaryotic Okazaki fragments together? a) DNA ligase b) DNA polymerase α c) DNA polymerase δ d) DNA polymerase β e) RNase H1 Answer: a Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

71) Which eukaryotic DNA polymerase is tightly associated with primase and responsible for Okazaki fragment synthesis initiation? a) polymerase α b) polymerase β c) polymerase ɤ d) polymerase δ e) polymerase ε Answer: a Difficulty: Easy Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

72) What evidence suggests that the assembly of DNA into nucleosomes is a very rapid event? a) Radiolabel is incorporated in a very short time. b) Nucleosomes have a very unusual shape. c) Electron micrographs of replicating DNA show nucleosomes forming on both daughter duplexes very near the replication fork. d) Electron micrographs of replicating DNA show nucleosomes forming on both daughter duplexes at a large distance from the replication fork. e) Nucleosomes are twice as big near the replication fork.

Answer: c Difficulty: Medium Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

73) The stepwise assembly of nucleosomes and their orderly spacing along the DNA is facilitated by __________________. a) a network of accessory proteins b) a number of histone chaperones that are able to accept newly synthesized histones and transfer them to daughter strands c) a number of histone chaperones that are able to accept parental histones and transfer them to daughter strands d) CAF-1, which is able to accept either parental histones or newly synthesized histones and transfer them to daughter strands e) all of these Answer: e Difficulty: Hard Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

74) What is the most common method for repairing damage to DNA? a) direct repair of the damage b) selective excision of the damaged section and use of the complementary strand to replace the excised portion c) simple removal of damaged portion without replacement d) excision of both strands and annealing of the two ends of DNA back together

Answer: b Difficulty: Medium Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

75) Which type of DNA repair removes, via a cut-and-patch mechanism, a variety of bulky lesions, like pyrimidine dimers and nucleotides to which various chemical groups have been attached? a) nucleotide excision repair b) base excision repair c) mismatch repair d) double-strand breakage repair e) All of these are correct.

Answer: a Difficulty: Easy Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

76) In the transcription-coupled repair pathway of nucleotide excision repair, how is the presence of a lesion thought to be detected? a) There are special enzymes that scan the DNA for such lesions. b) The lesion may be signaled by a stalled RNA polymerase. c) The lesion may be signaled by a stalled DNA polymerase. d) The lesion may be signaled by a stalled peptidyl transferase. e) The lesion may be detected single-stranded binding proteins.

Answer: b Difficulty: Medium Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

77) What is the advantage of transcription-coupled repair? a) It prevents cells from investing energy in transcription.

b) It ensures that the genes of least importance to the cell receive the highest priority on the repair list. c) It ensures that the genes of greatest importance to the cell receive the highest priority on the repair list. d) It is repairs noncoding sequences preferentially. e) It is the most accurate method of repair.

Answer: c Difficulty: Medium Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

78) Which method of repair can be slower, less efficient, and responsible for correcting DNA strands in the parts of the genome that are not being currently transcribed? a) transcription-coupled pathway of NER b) global genomic pathway of NER c) base excision repair d) replicative repair Answer: b Difficulty: Easy Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

79) What is the proper order of the steps involved in nucleotide excision repair?

1) release of the damaged DNA segment between the incisions 2) sealing of strand by DNA ligase 3) lesion recognition 4) separation of the duplex's two strands in the region of the lesion 5) filling of gap by DNA polymerase 6) biding of the XPB and XPD subunits of TFIIH to DNA in the region of the lesion 7) cutting of the damaged strand on both sides of lesion by endonucleases a) 6 – 3 – 4 – 7 – 1 – 5 – 2 b) 3 – 6 – 4 – 7 – 1 – 2 – 5 c) 3 – 6 – 7 – 4 – 1 – 5 – 2 d) 3 – 6 – 4 – 7 – 1 – 5 – 2 e) 6 – 3 – 7 – 4 – 2 – 1 – 5

Answer: d Difficulty: Hard Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

80) After cuts are made on the two sides of the lesion in nucleotide excision repair, what holds the damaged part of the strand in position for a while before its final removal? a) ionic bonds b) van der Waals forces c) hydrogen bonds d) 3'-5' phosphodiester linkages e) disulfide linkages Answer: c Difficulty: Medium Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

81) Which DNA repair mechanism removes altered nucleotides generated by reactive chemicals present in the diet or produced by metabolism? a) nucleotide excision repair b) base excision repair c) mismatch repair d) double-strand breakage repair e) the global genomic pathway Answer: b Difficulty: Easy Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

82) Place the steps in base excision repair in the correct order.

1) damaged base is removed by cleavage of glycosidic linkage attaching it to deoxyribose of backbone

2) baseless deoxyribose phosphate remaining in the site is excised by a specialized (AP) endonuclease and a DNA polymerase 3) DNA glycosylase recognizes the alteration in DNA 4) the strand is sealed by DNA ligase III 5) gap is filled by DNA polymerase β; it inserts a nucleotide complementary to the undamaged strand a) 1 - 3 – 2 – 5 – 4 b) 3 – 1 – 2 – 4 - 5 c) 1 – 3 – 2 – 4 – 5 d) 3 – 2 – 1 – 5 – 4 e) 3 – 1 – 2 – 5 – 4 Answer: e Difficulty: Hard Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

83) What enzyme cleaves the DNA backbone to remove the beheaded deoxyribose phosphate during base excision repair? a) an AP endonuclease b) phosphodiesterase activity of polymerase β c) 5'—>3' exonuclease d) 3'—>5' exonuclease e) DNA glycosylase Answer: a Difficulty: Medium Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

84) What enzyme is responsible for recognizing a chemical alteration in the DNA and removing the base by cleavage of the bond holding the base to the deoxyribose sugar moiety? a) an AP endonuclease b) phosphodiesterase activity of polymerase β c) 5'—>3' exonuclease d) 3'—>5' exonuclease e) DNA glycosylase

Answer: e Difficulty: Easy Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

85) Why did natural selection favor the use of thymine as a base in DNA instead of uracil even though uracil was presumably present in RNA, when it served as the genetic material during the early evolution of life? a) Thymine was more stable. b) Thymine paired better with adenine than did uracil. c) Retention of uracil as a DNA base would make it hard to tell whether a uracil was supposed to be at a particular site or whether it resulted from damage to cytosine. d) Thymine is resistant to all chemical treatments. e) Retention of uracil as a DNA base would make it hard to tell whether a uracil was supposed to be at a particular site or whether it resulted from damage to guanine.

Answer: c Difficulty: Medium Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

86) Which DNA repair mechanism recognizes a distortion in double helix geometry caused by DNA polymerase's insertion of an incorrect nucleotide during replication, one that escaped the enzyme's proofreading exonuclease? a) nucleotide excision repair b) base excision repair c) mismatch repair d) double-strand breakage repair e) transcription-coupled pathway Answer: c Difficulty: Easy Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

87) What must the mismatch repair system be able to distinguish in order to tell which nucleotide of a mismatched pair to replace? a) It must be able to distinguish the newly-made strand from the parental strand. b) It must be able to distinguish which chain has more important genetic information. c) It must be able to distinguish which chain contains the ribose sugars. d) It must be able to distinguish which chain has a higher G-C content.

Answer: a Difficulty: Medium Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

88) In mammalian cells, a complex of proteins binds to the broken ends of the DNA duplex and catalyzes a series of reactions that rejoin the broken strands. This is an example of what kind of repair? a) nucleotide excision repair b) base excision repair c) mismatch repair d) nonhomologous end joining Answer: d Difficulty: Easy Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

89) A double-stranded breakage repair pathway that requires the presence of a second chromosome carrying the same sequence of genes as the damaged chromosome is called _________. a) nonhomologous end joining repair b) homologous recombination c) NHEJ d) DNA methylation repair e) nonhomologous recombination Answer: b

Difficulty: Easy Learning Objective: LO 13.7 Outline four mechanisms of DNA repair.

Section Reference: Section 13.7 DNA Repair

90) What was the term used to describe the involvement of the public in determining useful mutations in plants derived from gamma garden seed production? a) GMO detection b) atomic energy awareness c) citizen science d) public agriculture Answer: c Difficulty: Easy Learning Objective: LO 13.8 Explain the purpose of gamma gardens.

Section Reference: Section 13.8 Green Cells: Gamma Gardens

91) Which of these crops is NOT a product of the gamma garden experiments? a) Star Ruby grapefruit b) Golden Promise barley c) Calrose 76 rice d) Golden rice Answer: d Difficulty: Easy Learning Objective: LO 13.8 Explain the purpose of gamma gardens.

Section Reference: Section 13.8 Green Cells: Gamma Gardens

92) Patients with the classical form of xeroderma pigmentosum have a defect in one of the genes involved in ______________. a) nucleotide excision repair b) replication c) base excision repair d) transcription e) base excitation repair

Answer: a Difficulty: Easy Learning Objective: LO 13.9 Compare the advantages and disadvantages of recruitment of polymerase η during DNA replication.

Section Reference: Section 13.9 Between Replication and Repair

93) What happens once damage caused by lesions in the genome, like a thymidine dimer, is bypassed during replication and replication continues? a) The bypass DNA polymerase η continues replication. b) The replicative DNA polymerase αβ continues replication. c) The bypass DNA polymerase ε continues replication. d) The normal replicative DNA polymerase continues replication.

Answer: d Difficulty: Medium Learning Objective: LO 13.9 Compare the advantages and disadvantages of recruitment of polymerase η during DNA replication.

Section Reference: Section 13.9 Between Replication and Repair

94) The DNA polymerases is a relatively large family of polymerases in which each member is specialized for incorporating nucleotides opposite particular types of DNA lesions in the template strand engage in a type of DNA synthesis called __________. They have an unusually spacious active site that ____________. a) translesion synthesis; unwinds DNA double helices b) translesion synthesis; is able to physically accommodate altered nucleotides that would not fit in the active site of a replicative polymerase c) transdimensional synthesis; incorporates the nucleotide that would have paired with the undamaged version of the template base d) transdimensional synthesis; unwinds DNA synthesis e) transliteral synthesis; is able to physically accommodate altered nucleotides that would not fit in the active site of a replicative polymerase Answer: b Difficulty: Hard Learning Objective: LO 13.9 Compare the advantages and disadvantages of recruitment of polymerase η during DNA replication.

Section Reference: Section 13.9 Between Replication and Repair

Question Type: Multiple Select

95) Using DNA to store data has the advantage of __________________. (Select all correct choices) a) the stability of the molecule b) the small size for information storage c) the absolute fidelity of replication d) more information “concentration” than the binary code systems Answer: a, b, d Difficulty: Medium Learning Objective: LO 13.5 Explain how DNA can be used to store data at the molecular level.

Section Reference: Section 13.5 Engineering Linkage: Storing Data in DNA

Question Type: Multiple Select

96) Using DNA to store data has the disadvantage of __________________. (Select all correct choices) a) the instability of the molecule b) slow processing of information c) the risk of mutations over repeated replication cycles d) more information “concentration” than the binary code systems Answer: b, c Difficulty: Medium Learning Objective: LO 13.5 Explain how DNA can be used to store data at the molecular level.

Section Reference: Section 13.5 Engineering Linkage: Storing Data in DNA

Question Type: Multiple Select

97) DNA sequences comprising the yeast origin of replication can be removed from yeast cells and inserted into bacterial DNA molecules. Because these sequences promote replication of the DNA in which they are contained, they are referred to as __________. (Select all correct choices) a) polygamous replicating sequences b) autonomous replicating sequences c) analogous replicating sequences d) ARSs Answer: b, d Difficulty: Medium Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

Question Type: Multiple Select

98) Autonomous replicating sequences that have been isolated and analyzed share several distinct elements. Which distinct elements below are shared by autonomous replicating sequences? (Select all correct choices) a) the core element b) a conserved sequence of 11 base pairs, which functions as a specific binding site for the origin recognition complex c) a conserved sequence of 11 base pairs, which functions as the origin recognition complex d) a conserved sequence of 22 base pairs, which functions as a specific binding site for the origin recognition complex Answer: a, b Difficulty: Medium Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

Question Type: Multiple Select

99) Which eukaryotic DNA polymerases require a sliding clamp to tether the DNA to the polymerase? (Select all correct choices) a) polymerase α b) polymerase β c) polymerase ɤ d) polymerase δ e) polymerase ε Answer: d, e Difficulty: Medium Learning Objective: LO 13.6 Outline the process of DNA replication in eukaryotic cells.

Section Reference: Section 13.6 DNA Replication in Eukaryotic Cells

Question Type: Multiple Select

100) Which are advantages of using recombinant DNA technology when compared with the gamma garden method of detecting favorably mutated crop varieties? (Select all correct choices) a) Recombinant DNA technology does not produce radioactive plants while gamma gardens did. b) Recombinant DNA technology is not accompanied by the risk of plant or animal exposure to radioactive isotopes while gamma gardens presented that potential danger. c) Recombinant DNA technology can produce targeted gene alterations which gamma garden mutations were randomly accumulated by plants. d) Recombinant DNA technology is slower to produce mutant plants, allowing for more deliberate study of their characteristics.

Answer: b, c Difficulty: Hard Learning Objective: LO 13.8 Explain the purpose of gamma gardens.

Section Reference: Section 13.8 Green Cells: Gamma Gardens

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 14

Question Type: Multiple Choice

1) The stages through which a cell passes from one cell division to the next constitute the _________. a) cell cycle b) life cycle c) biocycle d) energy cycle e) regeneration cycle Answer: a Difficulty: Easy Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

2) Based on cell activities readily visible in the light microscope, there are two major cell cycle phases, ________ and __________. a) M phase, cytokinesis b) interphase, cytokinesis c) M phase, C phase d) M phase, interphase e) C phase, interphase Answer: d Difficulty: Easy Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

3) The separation of duplicated chromosomes into two daughter nuclei is known as ________. a) meiosis b) cytokinesis c) chromokinesis d) chromatosis e) mitosis Answer: e Difficulty: Easy Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

4) The separation of the entire cell and its cytoplasm into two daughter cells is known as _______. a) meiosis b) cytokinesis c) chromokinesis d) chromatosis e) mitosis Answer: b Difficulty: Easy Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

5) What evidence suggests that a cell spends the majority of its time in interphase? a) Interphase is more useful. b) Only a small percentage of cells in a tissue or cell culture are seen to be in mitosis at any given time. c) A large percentage of cells in a tissue or cell culture are seen to be in mitosis at any given time. d) A moderate percentage of cells in a tissue or cell culture are seen to be in mitosis at any given time. e) Mitosis is too intricate a process to last very long.

Answer: b Difficulty: Hard Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

6) What is the average length of M phase in mammalian cells? a) about 1 hour b) about 10 minutes c) about 10 hours d) 4 hours and 35 minutes e) about a day Answer: a Difficulty: Easy Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

7) What is the average length of interphase in mammalian cells? a) It is exactly 10 hours in all cells. b) It is 12 hours long. c) There is not a good average since it depends on the cell type and conditions. d) It may last up to a day. e) On average, it lasts about 3 hours.

Answer: c Difficulty: Hard Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

8) When do most of the preparations for mitosis occur, including such activities as DNA replication?

a) cytokinesis b) M phase c) interphase d) telophase e) enterophase Answer: c Difficulty: Easy Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

9) The period in the cell cycle between the end of cell division and the beginning of DNA synthesis is called the _____ phase. a) G1 b) S c) G2 d) M e) G0 Answer: a Difficulty: Easy Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

10) DNA replication and the production of additional histones occur during what part of the cell cycle? a) G1 b) S c) G2 d) M e) G0 Answer: b Difficulty: Easy

Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

11) The total length of the cell cycle of cells in a cell culture is 24 hours. M phase is found to be 1 hour, S phase is found to be 9 hours and G2 is found to be 4.5 hours. How long is G1? a) 24 hours b) 9.5 hours c) 9 hours d) 1 hour e) 4.5 hours Answer: b Difficulty: Medium Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

12) Which cells typically have very short cell cycles on the order of less than 30 minutes? a) cells in a cleaving frog embryo b) cells in mammalian liver tissue c) mammalian muscle cells d) both cells in a cleaving frog embryo and mammalian muscle cells e) nerve cells Answer: a Difficulty: Medium Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

13) Which cells typically have cell cycles lasting several months? a) cells in a cleaving frog embryo b) cells in mammalian liver tissue c) mammalian embryo cells

d) both cells in a cleaving frog embryo and mammalian embryo cells e) nerve cells Answer: b Difficulty: Medium Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

14) What stimulus can induce liver cells to proliferate? a) interaction with an appropriate antigen b) interaction with an appropriate antibody c) surgical removal of part of the liver d) a buildup of bile in the liver e) glycogen buildup in the liver Answer: c Difficulty: Medium Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

15) Which of the cells below normally possess a relatively high level of mitotic activity? a) stem cells of various adult tissues b) hematopoietic stem cells that give rise to red and white blood cells c) stem cells at the base of numerous epithelia that line the body cavities d) the relatively unspecialized cells found near the tips of plant roots and stems e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

16) What property below do stem cells possess that is NOT found in most other cells? a) They exhibit synchronous cell division. b) They do not replicate their DNA before cell division. c) The two daughter cells have different properties or fates. d) They exhibit symmetric cell division. e) They secrete lipids and glycolipids.

Answer: c Difficulty: Medium Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

17) What types of non-stem cells also engage in asymmetric or unequal divisions? a) formation of oocytes and polar bodies b) formation of spermatogonia c) division of red blood cells d) division of B cells e) division of liver cells Answer: a Difficulty: Medium Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

18) Cells that have stopped dividing and are arrested in a stage preceding replication of cytoplasmic contents and organelles are said to be in ______ state. a) G1 phase b) S phase c) G2 phase d) M phase e) G0 phase Answer: e Difficulty: Easy

Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

19) What must happen in order for a cell to move from G0 to G1 phase? a) It must divide. b) It must generate an external signal. c) It must receive a growth-promoting signal. d) It must divide and receive a growth-promoting signal. e) It must grow extremely large.

Answer: c Difficulty: Easy Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

20) What disease can be defined as resulting from a breakdown in a cell's ability to regulate its own division? a) multiple sclerosis b) cancer c) emphysema d) diabetes e) heart disease Answer: b Difficulty: Easy Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

21) You are carrying out experiments in cell fusion by fusing together cells at different stages of the cell cycle. You then observe the behavior of each nucleus residing in the combined cytoplasm of the two cells. Which of the following responses would occur if you fused a G2 cell to a cell in the M phase?

a) The nucleus from the G2 cell would start to replicate its DNA. b) The G2 nucleus would undergo premature chromosomal condensation to form a set of elongated, single compacted chromosomes. c) The M phase nucleus would be affected in such a way that its compacted chromosomes decondense. d) The G2 nucleus would undergo premature chromosomal condensation, but the compacted chromosomes would be visibly doubled.

Answer: d Difficulty: Hard Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

22) You are carrying out experiments in cell fusion by fusing together cells at different stages of the cell cycle. You then observe the behavior of each nucleus residing in the combined cytoplasm of the two cells. Which of the following responses would occur if you fused an S-phase cell to a cell in the M phase? a) The nucleus from the M phase cell would start to replicate its DNA. b) The S-phase nucleus would undergo premature chromosomal condensation to form a set of elongated compacted chromosomes. c) The M phase nucleus would be affected in such a way that its compacted chromosomes decondense. d) The chromatin in the S-phase nuclei would be compacted, but pulverized chromosomal fragments would form. e) The S-phase nucleus would undergo premature chromosomal condensation; the compacted chromosomes would be visibly doubled.

Answer: d Difficulty: Hard Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

23) The regulatory subunit of maturation-promoting factor ________. a) transfers a phosphate group to certain serine and threonine residues of specific protein substrates b) is called cyclin because its concentration rises and falls predictably as the cell cycle progresses

c) converts ATP to ADP d) converts ADP to ATP e) transfers a phosphate group to certain tyrosine residues of specific protein substrates Answer: b Difficulty: Easy Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

24) The first transition point in yeast cells that commits the cells to entering S phase occurs just before the end of ___ and is called _______. a) G2, START b) G1, MPF c) G2, MPF d) G1, BEGIN e) G1, START Answer: e Difficulty: Medium Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

25) Movement past the transition point near the end of G2 that moves cells on to mitosis requires cdc2 activation by _______. a) Na+ ions b) mitotic cyclins c) ATP d) Na+-K+ ATPase e) mitotic chromatin Answer: b Difficulty: Medium Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

26) What triggers the entry of a yeast cell into mitosis? a) the addition of inhibitory phosphate groups to Cyclin-Cdk by the Cdc25 phosphatase b) the removal of inhibitory phosphate groups from Cyclin-Cdk by the Cdc25 phosphatase c) the addition of inhibitory phosphate groups to Cyclin-Cdk by the Wee1 kinase d) the removal of inhibitory phosphate groups from Cyclin-Cdk by the Wee1 kinase e) the removal of phosphate groups from the Wee1 kinase Answer: b Difficulty: Hard Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

27) What protein is required to drive the mammalian cell through all cell cycle stages? a) Cdk2 b) Cdk1 c) Wee1 kinase d) Cdk4 e) cyklin D1 Answer: b Difficulty: Hard Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

28) Checkpoints in the cell cycle _______________. a) recognize DNA damage b) detect cellular abnormalities c) can “halt” progression through the cell cycle if abnormalities in replication are detected d) may allow cells to become senescent e) all are correct choices Answer: e

Difficulty: Medium Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

29) What multiprotein complex has recently been shown to play a significant role in chromosome compaction? a) compressin b) condensin c) elastin d) loopin e) mitosin Answer: b Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

30) What happens if condensin protein is removed from frog egg extract used to treat chromosomes in vitro? a) Compaction of the chromosomes continues as normal. b) Compaction of the chromosomes occurs more quickly than normal. c) Compaction of the chromosomes is prevented. d) The DNA expands further and fills the entire cell. e) Compaction of the chromosomes occurs but occurs more slowly.

Answer: c Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

31) What activates condensin at the onset of mitosis? a) Na+ ions

b) phosphorylation of several of its subunits by the Cdk-cyclin that drives cells from G2 into mitosis c) phosphorylation of several of its subunits by the Cdk-cyclin that drives cells from G1 into mitosis d) phosphorylation of several of its subunits by the Cdk-cyclin that drives cells from G1 into S phase e) dephosphorylation of several of its subunits by the Cdk-cyclin that drives cells from G2 into mitosis Answer: b Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

32) What molecule is responsible for holding sister chromatids together through G2 and into mitosis? a) compressin b) cohesin c) condensin d) connexin e) contractin Answer: b Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

33) What appears to be responsible for the tighter cohesin-mediated adhesion between chromosomes seen at centromeres rather than along the chromosome arms? a) elevated phosphorylation b) a kinase found at the centromere that phosphorylates cohesin c) a phosphatase found at the centromere that removes phosphate groups from cohesin d) a phosphatase found in the chromosome arms that removes phosphate groups from cohesin e) a phosphatase found in the chromosome arms that adds phosphate groups to cohesin Answer: c Difficulty: Medium

Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

34) At the outer surface of the centromere of each chromatid is a proteinaceous, buttonlike structure called the __________. a) primary constriction b) residence c) kinetochore d) proteasome e) kinetosome Answer: c Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

35) When is a kinetochore assembled on the centromere? a) prophase b) anaphase c) telophase d) metaphase e) interphase Answer: a Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

36) As animal cells enter mitosis, their microtubules disassemble and then reassemble forming the mitotic spindle with a focus at the ________, a special microtubule-organizing structure. a) kinetosome b) centrosome c) kinetochore d) centromere e) chromosome

Answer: b Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

37) How would you describe the orientation of the two centrioles of the centrosome relative to each other? a) oriented at right angles b) oriented linearly c) oriented in a stacked manner d) reversed e) converse Answer: a Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

38) What triggers the start of centrosome duplication? a) phosphorylation of a centrosomal protein by ATPase b) phosphorylation of a centrosomal protein by Cdk2 c) dephosphorylation of a centrosomal protein by Cdk2 d) dephosphorylation of a centrosomal protein by ATPase e) phosphorylation of a centrosomal protein focal adhesion kinase Answer: b Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

39) The start of centrosome duplication begins at the ______ transition time. a) M-G1 b) G1-S

c) S-G2 d) G2-M e) G1-M Answer: b Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

40) The process of centriole replication begins in the cytoplasm with the appearance of a small ________. a) pericentriole b) procentriole c) precentriole d) procentrosome e) pericentrosome Answer: b Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

41) Which of the following is involved with the machinery that links kinetochores to dynamic microtubules? a) motor proteins b) a protein complex called Ndc80 c) the KMN network d) curling microtubule protofilaments e) all of these are correct Answer: e Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

42) Even before cytokinesis has been completed, the two centrioles of a daughter cell disengage, an event that is triggered by the enzyme _________, which becomes activated late in mitosis. a) invertase b) centriolase c) separase d) disengagase e) activase Answer: c Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

43) The sunburst arrangement of microtubules that forms around each centrosome during early prophase is called ________. a) a sunflower b) an arnost c) an aster d) an astral fiber e) a barrel Answer: c Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

44) What drives the separation of centrosomes? a) motor proteins associated with microfilaments b) motor proteins associated with adjacent microtubules c) contraction of individual microfilaments d) sliding of adjacent microfilaments over one another e) contraction of adjacent microtubules Answer: b Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

45) What controls the progression of a cell from G2 to M? a) mitotic cyclin B-Cdk1 b) synthetic Cdk c) the spindle d) chromosome compaction e) mitotic cyclin A- Cpk Answer: a Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

46) Microtubules are nucleated in the vicinity of the centrosomes if cells possess centrosomes.

Where do they nucleate in cells lacking centrosomes? a) in the vicinity of the nucleolus b) in the vicinity of the mitochondria c) in the vicinity of the chromosomes d) in the vicinity of the cell membrane e) in the vicinity of the lysosomes Answer: c Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

47) What permits the interaction between the cytoplasmically-formed mitotic spindle and the chromosomes to occur? a) nuclear envelope breakdown b) nucleosome breakdown c) nucleolus breakdown d) chromatin dissolution e) chromosome condensation

Answer: a Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

48) What molecular motor uses microtubules to disassemble the nuclear membrane? a) myosin b) kinesin c) dynein d) calpain e) calmodulin Answer: c Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

49) Which organelles become fragmented during mitosis in mammalian cells? a) mitochondria b) Golgi complex c) ER d) peroxisomes e) chloroplasts Answer: b Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

50) The current view of the fate of the ER during mitosis is that ________. a) the ER network becomes membrane sheets which are divided between the daughter cells b) the ER is broken into its component macromolecules during mitosis, and it is built up from scratch after mitosis c) the ER is broken up into small vesicles that reassemble later

d) the ER becomes part of the Golgi complex during mitosis e) the ER joins with mitochondria at the beginning of mitosis Answer: a Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

51) What are the three major components of the nuclear envelope? a) nuclear pores, nuclear lamina, nuclear membrane aggregates b) RER, nuclear lamina, Na+-K+ pump c) nuclear pore complexes, nuclear lamina, nuclear membranes d) mitotic kinases, nuclear lamina, nuclear pore complexes e) phospholipids, nuclear pore complexes, nucleoplasm Answer: c Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

52) What initiates the disassembly of the three major components of the nuclear envelope? a) phosphorylation of key substrates by mitotic kinases, particularly cyclin B-Cdk1 b) dephosphorylation of key substrates by mitotic phosphatases, particularly cyclin B-Cdk1 c) a cascade begun by ATP synthase d) phosphorylation of key substrates by mitotic phosphatases, particularly cyclin B-Cdk e) methylation of key substrates by mitotic kinases, particularly cyclin B-Cdk1 Answer: a Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

53) The nuclear pore complexes are disassembled _________.

a) as the interactions between nucleoporin complexes are disrupted and the proteins dissociate into the surrounding medium b) by depolymerization of the lamin filaments c) as their integrity is disrupted mechanically as holes are torn in the complexes by cytoplasmic dyneins associated with the outer nuclear membrane d) by cytoplasmic dyneins e) by cytoplasmic microtubules and microfilaments Answer: a Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

54) The nuclear lamina is disassembled _________. a) as the interactions between nucleoporin complexes are disrupted and the proteins dissociate into the surrounding medium b) by depolymerization of the lamin filaments c) as its integrity is disrupted mechanically as holes are torn in the complexes by cytoplasmic dyneins associated with the outer nuclear membrane d) by cytoplasmic dyneins e) by cytoplasmic microtubules and microfilaments Answer: b Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

55) The integrity of the nuclear membrane is disrupted _________. a) as the interactions between nucleoporin complexes are disrupted and the proteins dissociate into the surrounding medium b) by depolymerization of the lamin filaments c) as its integrity is disrupted mechanically as holes are torn into it by cytoplasmic dyneins associated with the outer nuclear membrane d) by cytoplasmic kinesins e) by cytoplasmic microtubules and microfilaments Answer: c

Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

56) What is an alternative to the classical view of the fate of the membranous portion of the nuclear envelope? a) fragmentation into a population of small vesicles that disperse throughout the mitotic cell b) absorption of the membranes of the nuclear envelope into the membranes of the Golgi complex c) absorption of the membranes of the nuclear envelope into the membranes of the peroxisomes d) absorption of the membranes of the nuclear envelope into the membranes of the ER e) absorption of the membranes of the nuclear envelope into the membranes of the nucleoplasm Answer: d Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

57) What is the event that begins prometaphase? a) the complete compaction of the chromosomes b) the disappearance of the nucleolus c) the dissolution of the nuclear envelope d) the reappearance of the nucleolus e) the connection of chromosomes to spindle fibers Answer: c Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

58) Which stage of mitosis starts as sister chromatids split apart and begin to move toward opposite poles? a) prophase b) metaphase c) prometaphase

d) anaphase e) telophase Answer: d Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

59) Which of the following multiprotein complexes acts primarily during interphase to ubiquitinate proteins and target them for destruction by a proteasome? a) SCF b) APC c) anaphase promoting complex d) both SCF and APC e) proteasomal activating complex Answer: a Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

60) How does securin get its name? a) Securin secures chromosomes to the cell membrane. b) Securin secures the attachment between sister chromatids. c) Securin determines which substances can enter the nucleus and which cannot. d) Securin secures the binding of the kinetochore to the chromosome. e) Securin attaches kinetochores to the spindle.

Answer: b Difficulty: Medium Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

61) On occasion, the two kinetochores of sister chromatids will become attached to microtubules from the same spindle pole; this condition is referred to as ________.

a) osteosarcoma b) systolic attachment c) syntelic attachment d) opposite chromatid attachment e) synthetisism Answer: c Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

62) What is the name of the enzyme that responds to the lack of bipolar tension when both chromatids are attached to microtubules from the same spindle pole, and helps to correct the abnormality? a) streptokinase b) Aurora B kinase c) Cdc kinase d) protein kinase e) tubulin kinase Answer: b Difficulty: Easy Learning Objective: LO 14.2 Outline the major events of mitosis and cytokinesis.

Section Reference: Section 14.2 M phase: Mitosis and Cytokinesis

63) Epithelial cell division and turnover is thought to be regulated through the activity of: a) voltage-gated channels b) ligand-gated channels c) mechano-gated channels d) all are correct choices Answer: c Difficulty: Easy Learning Objective: LO 14.3 Describe the role of membrane tension in cell division Section Reference: Section 14.3 Engineering Linkage: The Role of Membrane Tension in Cell Division

64) The mechanosensitive ion channel which drives cell division in epithelial cell layers is: a) a trimer of Piezo1 subunits forming a channel with a central pore and two long curved arms b) a dimer of Piezo1 subunits forming a channel with a central pore and two long curved arms c) a trimer of Piezo1 subunits forming a channel with a central pore and three long curved arms d) a trimer of Piezo2 subunits forming a channel with a central pore and two long curved arms e) a dimer of Piezo2 subunits forming a channel with a central pore and three long curved arms Answer: c Difficulty: Medium Learning Objective: LO 14.3 Describe the role of membrane tension in cell division Section Reference: Section 14.3 Engineering Linkage: The Role of Membrane Tension in Cell Division

65) The flux of which ion appears to play a role in triggering Piezo1-mediated cell division in stretched epithelial cell layers? a) potassium b) sodium c) magnesium d) calcium Answer: d Difficulty: Easy Learning Objective: LO 14.3 Describe the role of membrane tension in cell division Section Reference: Section 14.3 Engineering Linkage: The Role of Membrane Tension in Cell Division

66) What is the name given to the site at which a dividing plant cell will build its cell division plane? a) pre-mitosis band b) prophase band c) preprophase band d) telophase band Answer: c

Difficulty: Easy Learning Objective: LO 14.4 Explain the aspects of cell division unique to plants.

Section Reference: Section 14.4 Green Cells: Unique Aspects of Plant Cell Division

67) Regarding the formation of the cell wall partition between two newly created daughter plant cells, which statement is INCORRECT? a) cell wall formation begins in the center of the cell and moves laterally b) a simpler precursor known as the cell disc is formed first c) Golgi-derived vesicles play a role in forming the new cell wall d) the assembly of proteins required during the cell wall partition formation is known as the phragmoplast Answer: b Difficulty: Medium Learning Objective: LO 14.4 Explain the aspects of cell division unique to plants.

Section Reference: Section 14.4 Green Cells: Unique Aspects of Plant Cell Division

68) What is the name of the process during which chromosome number is reduced so that each cell produced has a haploid number of chromosomes? a) mitosis b) meiosis c) cytokinesis d) sexual differentiation e) meitosis Answer: b Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

69) Cells that have a single set of chromosomes are said to have a _______ number of chromosomes; cells that contain two full sets of chromosomes are said to have a ______ number of chromosomes.

a) diploid, haploid b) haploid, diploid c) diploid, diploid d) haploid, haploid e) monoploid, polyploid Answer: b Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

70) What occurs during pairing of chromosomes in prophase of meiosis I that increases genetic variability? a) further condensation of chromosomes b) genetic recombination between homologous chromosomes c) lots of mutations d) chromosomes lose lots of fragments e) gene duplication Answer: b Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

71) Organisms in which meiotic divisions are closely linked to gamete formation, as in the case where meiosis occurs just prior to the differentiation of the spermatozoa, exhibit ___________. a) initial meiosis b) terminal meiosis c) zygotic meiosis d) sporic meiosis e) intermediate meiosis Answer: b Difficulty: Easy

Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

72) ___________ in males and _______ in females undergo mitosis giving rise to the cells that will carry out meiosis and eventually produce mature gametes. a) Oogonia, spermatogonia b) Spermatogonia, oocytes c) Spermatogonia, oogonia d) Oogonia, spermatocytes e) Spermatocytes, oocytes Answer: c Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

73) What usually happens to vertebrate eggs immediately after they have been fertilized? a) Cytokinesis begins. b) They start to grow. c) Mitosis begins. d) Meiosis is completed. e) The egg sheds lots of cytoplasm.

Answer: d Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

74) At what stage of meiosis are vertebrate eggs usually fertilized? a) prophase II b) metaphase I c) interkinesis

d) metaphase II e) anaphase I Answer: d Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

75) Which word below characterizes the adult generation that is produced after zygotic meiosis? a) diploid b) haploid c) polyploid d) aneuploid Answer: b Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

76) By which process are gametes produced from a gametophyte? a) meiosis b) cytokinesis c) mitosis d) fission e) replication Answer: c Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

77) In the human female, when is prophase I of meiosis initiated?

a) at puberty b) prior to birth c) between the ages of 4 and 6 d) at the beginning of each menstrual cycle e) at the end of each menstrual cycle Answer: b Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

78) In the human female, after their long arrest, when do oocytes resume meiosis? a) just prior to ovulation b) prior to birth c) between the ages of 4 and 6 d) at the end of each menstrual cycle e) just after birth Answer: a Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

79) When do homologous regions of DNA in homologous chromosomes first associate? a) leptotene b) zygotene c) pachytene d) diplotene e) diakinesis Answer: a Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

80) What is the first step in genetic recombination? a) lengthening of the chromosomes b) the introduction of single-stranded breaks in aligned DNA molecules c) the introduction of double-stranded breaks in aligned DNA molecules d) the accurate alignment of DNA molecules e) the exchange of pieces of DNA between homologous chromosomes Answer: c Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

81) During what stage do studies of mice and yeast cells suggest that DNA breaks leading to recombination begin? a) pachytene b) leptotene c) diakinesis d) zygotene e) diplotene Answer: b Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

82) Mice with mutations that prevent the clustering of telomeres in leptotene develop defects.

What do these defects suggest the purpose of clustering telomeres may be? a) termination of synapsis b) facilitation of synapsis, genetic recombination and gamete formation c) prevention of chromosome alignment until synapsis begins d) spread of chromosomes out in preparation for synapsis

e) initiation of the dissolution of the nuclear envelope Answer: b Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

83) Synapsis is accompanied by the formation of a complex, ladder like structure made of three parallel bars with transverse protein filaments connecting its central element with two lateral elements. What is the name of this structure? a) synaptonemal ladder b) ladderellen c) synaptonemal complex d) nuclear complex e) nucleolar complex Answer: c Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

84) What is the presently accepted function of the synaptonemal complex thought to be? a) It serves to initiate genetic recombination. b) It maintains RNA in association with the chromosomes. c) It functions primarily as a scaffold to allow interacting chromatids to complete crossover activities. d) It prevents the breakage of the DNA double helix at the wrong place. e) It assures that the DNA double helix breaks at exactly the right place.

Answer: c Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

85) What event marks the end of zygotene? a) the beginning of synapsis b) the beginning of genetic recombination c) the end of synapsis d) the start of metaphase e) the formation of the synaptonemal complex Answer: c Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

86) What stage of prophase I of meiosis begins when synapsis ends? a) pachytene b) leptotene c) diakinesis d) zygotene e) diplotene Answer: a Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

87) What stage of prophase I is usually recognized by the dissolution of the synaptonemal complex and the tendency of homologous chromosomes of the bivalents to pull away somewhat from each other? a) pachytene b) leptotene c) diakinesis d) zygotene e) diplotene

Answer: e Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

88) As they separate, homologous chromosomes are seen to remain attached to each other at specific points by X-shaped structures at the crossover sites called _________. a) crossover rings b) chiasmata c) chiastrata d) diplonema e) crenata Answer: b Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

89) Crossing-over is important for ___________. (Select all correct choices) a) ensuring proper chromosome segregation b) ensuring proper chromosome miscegenation c) introducing additional genetic variation into the population d) delaying meiosis for an appropriate and necessary amount of time Answer: a, c Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

90) During which stage of prophase I does the bulk of oocyte growth occur? a) pachytene

b) leptotene c) diakinesis d) zygotene e) diplotene Answer: e Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

91) At meiosis metaphase I, the two homologous chromosomes of each bivalent are connected to spindle fibers from the _________. a) same spindle pole b) opposite spindle poles c) the centromere of its neighboring chromosome d) the centromere of its homologue e) random centromeres of other chromosomes Answer: b Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

92) In meiosis I, kinetochores of sister chromatids are connected as a unit to microtubules from __________. a) the same spindle pole b) opposite spindle poles c) the centromere of its neighboring chromosome d) the centromere of its homologue e) random centromeres of other chromosomes Answer: a Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

93) Which molecules and components are found within the plant cell preprophase band? (Select all correct choices) a) cortical microtubules b) actin filaments c) myosin filaments d) organelles Answer: a, b, d Difficulty: Medium Learning Objective: LO 14.4 Explain the aspects of cell division unique to plants.

Section Reference: Section 14.4 Green Cells: Unique Aspects of Plant Cell Division

94) The random assortment of chromosomes at anaphase I accounts for a large amount of the _________ within a species. a) stability b) genetic variability c) biochemical inhibition d) genetic uniformity e) genetic forbearance Answer: b Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

95) What is required for the separation of homologous chromosomes at anaphase I of meiosis I? a) the separation of sister centromeres b) the dissolution of the chiasmata c) the dissolution of the centromeres d) the dissolution of the centrosomes e) the separation of nucleosomes

Answer: b Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

96) Why do the centromeres of sister chromatids stay firmly connected during anaphase I of meiosis I? a) They are fused together at the level of their double helices. b) The cohesin situated at the centromeres is protected from proteolytic attack. c) The cohesin situated at the centromeres is digested by nucleolytic enzymes. d) The DNA of the centromeres is hydrolyzed by proteolytic enzymes. e) The proteins of the centromere region are impervious to lipase digestion.

Answer: b Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

97) The generally short-lived stage between the two meiotic divisions is called ________. a) interphase b) intermediacy c) interkinesis d) middlephase e) zwitterphase Answer: c Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

98) During which stage of meiosis do the chromosomes become recompacted after interkinesis?

a) telophase I b) telophase II c) prophase II d) metaphase II e) prophase I Answer: c Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

99) During which phase of meiosis do the kinetochores of sister chromatids face opposite poles as they line up in the center of the cells, with the centromeres of sister chromatids attached to chromosomal spindle fibers from opposite spindle poles? a) prophase II b) metaphase II c) anaphase II d) metaphase I e) telophase II Answer: b Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

100) Due to the reciprocal exchange of DNA strands that occurs during genetic recombination, the two duplexes are covalently linked to one another to form a joint molecule called a(n) __________ that contains a pair of DNA crossovers called __________. a) homoduplex, Holliday junctions b) heteroduplex, Holliday junctions c) Holliday junction, heteroduplexes d) Holliday junction, homoduplexes e) heteroduplexes, junctional complexes Answer: b

Difficulty: Medium Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

101) The Holliday junction recombination intermediate is not a static structure because the linkage point may move in one direction or another, a process known as _________. a) slippage b) intrusion c) branch fusion d) branch migration e) extrusion Answer: d Difficulty: Easy Learning Objective: LO 14.5 Compare the roles of mitosis and meiosis in the life cycles of both plants and animals.

Section Reference: Section 14.5 Meiosis

Question Type: Multiple Select

102) Once a fission yeast cell passes START, the cell is committed to DNA and cellular replication. What is responsible for activating cdc2 at this time? (Select all correct choices) a) one or more G1 cyclins b) one or more G2 cyclins c) one or more S cyclins d) one or more M cyclins e) one or more G0 cyclins Answer: a, b Difficulty: Medium Learning Objective: LO 14.1 Explain how the phases of the cell cycle can vary among different types of cells.

Section Reference: Section 14.1 The Cell Cycle

103) Which significant cellular activities appear to be regulated by Piezo1? (Select all correct choices) a) enabling of touch sensation in some neurons b) controlling of white blood cell volume c) controlling of red blood cell volume d) regulation of vascular development e) promoting cell division in epithelial cell layers Answer: a, c, d, e Difficulty: Medium Learning Objective: LO 14.3 Describe the role of membrane tension in cell division Section Reference: Section 14.3 Engineering Linkage: The Role of Membrane Tension in Cell Division

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 15

Question Type: Multiple Choice

1) How do cells in the body of a multicellular organism usually communicate with each other? a) intracellular messenger molecules b) direct connection by cells through long projections c) extracellular messenger molecules d) electrical signals between cells e) ion transport between cells Answer: c Difficulty: Easy Learning Objective: LO 15.1 Explain the role of each of the key molecules involved in signal transduction.

Section Reference: Section 15.1 The Basic Elements of Cell Signaling Systems

2) Sometimes an enzyme is activated by a receptor and brings about the cellular response by generating a second messenger. Such an enzyme is called __________. a) an activator b) an effector c) an affector d) a refractor e) a generator Answer: b Difficulty: Easy Learning Objective: LO 15.1 Explain the role of each of the key molecules involved in signal transduction.

Section Reference: Section 15.1 The Basic Elements of Cell Signaling Systems

3) When a signal is initiated by the binding of an extracellular ligand, what is the immediate outcome of that signal? a) A protein in the middle of an intracellular signaling pathway is activated. b) A protein at the top of an intracellular signaling pathway is activated. c) A protein at the top of an extracellular signaling pathway is activated. d) A protein at the top of an intracellular signaling pathway is deactivated. e) A protein at the bottom of an intracellular signaling pathway is activated.

Answer: b Difficulty: Medium Learning Objective: LO 15.1 Explain the role of each of the key molecules involved in signal transduction.

Section Reference: Section 15.1 The Basic Elements of Cell Signaling Systems

4) Which of the following is NOT generally characteristic of pathways activated by second messengers? a) Each signaling pathway consists of a series of distinct proteins that operate in sequence. b) Each protein in the pathway typically acts by altering the conformation of the previous (upstream) protein in the series, an event that activates or inhibits the protein. c) Alterations in the conformations of signaling proteins are often accomplished by protein kinases and protein phosphatases that, respectively, add or remove phosphate groups from other proteins. d) Some phosphatases and protein kinases in the pathway have numerous proteins as their substrates; others act on only a single protein substrate or a single amino acid of a protein substrate. e) Many of the protein substrates of the pathway enzymes are enzymes themselves, like other kinases and phosphatases, but they include ion channels, transcription factors and various regulatory molecules.

Answer: b Difficulty: Hard Learning Objective: LO 15.1 Explain the role of each of the key molecules involved in signal transduction.

Section Reference: Section 15.1 The Basic Elements of Cell Signaling Systems

5) What kinds of responses have NOT been observed when signals traveling down signaling pathways reach their target proteins?

a) a change in gene expression b) a change in ion permeability c) cessation of DNA synthesis and degradation of DNA d) the death of the cell e) an alteration of the activity of metabolic enzymes Answer: c Difficulty: Medium Learning Objective: LO 15.1 Explain the role of each of the key molecules involved in signal transduction.

Section Reference: Section 15.1 The Basic Elements of Cell Signaling Systems

6) What is the origin of virtually all of the signals that regulate cellular activities? a) the cell surface b) the nucleus c) the nucleolus d) the endoplasmic reticulum e) the cell wall Answer: a Difficulty: Easy Learning Objective: LO 15.1 Explain the role of each of the key molecules involved in signal transduction.

Section Reference: Section 15.1 The Basic Elements of Cell Signaling Systems

7) The overall process by which information carried by extracellular messenger molecules is translated into changes that occur inside the cell is called signal ___________. a) digestion b) destruction c) interaction d) transduction e) induction Answer: d Difficulty: Easy Learning Objective: LO 15.1 Explain the role of each of the key molecules involved in signal transduction.

Section Reference: Section 15.1 The Basic Elements of Cell Signaling Systems

8) If a hormone receptor is degraded along with its ligand after internalization, what is the effect on the cell's ability to respond to the hormone? a) The response is enhanced. b) The cell has increased sensitivity to subsequent stimuli. c) The cell has decreased sensitivity to subsequent stimuli. d) The cell exhibits no change in responsiveness to subsequent stimuli.

Answer: c Difficulty: Medium Learning Objective: LO 15.1 Explain the role of each of the key molecules involved in signal transduction.

Section Reference: Section 15.1 The Basic Elements of Cell Signaling Systems

9) Which amino acids are known to be phosphorylated by protein kinases? a) tyrosine, threonine, glycine b) threonine, serine, tryptophan c) serine, threonine, tyrosine d) phenylalanine, serine, tyrosine e) serine, leucine, tyrosine Answer: c Difficulty: Hard Learning Objective: LO 15.1 Explain the role of each of the key molecules involved in signal transduction.

Section Reference: Section 15.1 The Basic Elements of Cell Signaling Systems

10) Which molecule below is NOT likely to act as either a neurotransmitter or hormone? a) glucose b) glycine c) dopamine d) eicosanoids e) thyroid hormone

Answer: a Difficulty: Easy Learning Objective: LO 15.2 Identify the key extracellular messengers and their receptors.

Section Reference: Section 15.2 A Survey of Extracellular Messengers and Their Receptors

11) From which molecule are steroids derived? a) CO2 b) cholesterol c) glucose d) phospholipids e) glucagons Answer: b Difficulty: Easy Learning Objective: LO 15.2 Identify the key extracellular messengers and their receptors.

Section Reference: Section 15.2 A Survey of Extracellular Messengers and Their Receptors

12) Which signaling molecules are nonpolar molecules containing 20 carbons that are derived from a fatty acid named arachidonic acid? a) eicosanoids b) steroids c) acetylcholine d) acetylsalicylic acid e) epinephrine Answer: a Difficulty: Easy Learning Objective: LO 15.2 Identify the key extracellular messengers and their receptors.

Section Reference: Section 15.2 A Survey of Extracellular Messengers and Their Receptors

13) Which of the following processes is NOT reported to be regulated by eicosanoids? a) pain b) inflammation c) blood pressure

d) blood clotting e) neurotransmission Answer: e Difficulty: Easy Learning Objective: LO 15.2 Identify the key extracellular messengers and their receptors.

Section Reference: Section 15.2 A Survey of Extracellular Messengers and Their Receptors

14) What allows efficient recognition of extracellular signaling molecules by receptors on the responding cell's surface? a) low affinity binding with the signaling molecule b) high affinity binding with the signaling molecule c) denaturing of the signaling molecule d) stabilization of the signaling molecule e) infiltration of the signaling molecule Answer: b Difficulty: Easy Learning Objective: LO 15.2 Identify the key extracellular messengers and their receptors.

Section Reference: Section 15.2 A Survey of Extracellular Messengers and Their Receptors

15) What role do activated steroid receptors play in the cell? a) activation of inactive enzymes b) inactivation of active enzymes c) ligand-regulated transcription factors d) opening of specific ion channels e) activation of cytoplasmic proteins Answer: c Difficulty: Easy Learning Objective: LO 15.2 Identify the key extracellular messengers and their receptors.

Section Reference: Section 15.2 A Survey of Extracellular Messengers and Their Receptors

16) Where are steroid receptors generally located and where do they bind the steroid hormone once it enters the cell?

a) They are located and bind the steroids in the cytoplasm. b) They are located and bind the steroids in the middle of the cell membrane. c) They are located and bind the steroids on the extracellular membrane surface. d) They are located and bind the steroids on the intracellular membrane surface. e) The receptors are located in the cytoplasm but they bind their ligands in the lysosomes.

Answer: a Difficulty: Easy Learning Objective: LO 15.2 Identify the key extracellular messengers and their receptors.

Section Reference: Section 15.2 A Survey of Extracellular Messengers and Their Receptors

17) The Gprotein-coupled receptor family of proteins often contain seven ____________________________ as a structural motif. a) tyrosine-methionine dipeptides b) transmembrane β-pleated sheets c) transmembrane α-helices d) methionine-tryptophan dipeptides e) nucleotides attached Answer: c Difficulty: Easy Learning Objective: LO 15.2 Identify the key extracellular messengers and their receptors.

Section Reference: Section 15.2 A Survey of Extracellular Messengers and Their Receptors

18) What is the largest protein superfamily encoded by animal genomes? a) Gprotein-coupled receptors b) RTKs c) steroid receptors d) tubulin superfamily e) ligand-gated channels Answer: a Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

19) Which of the following are NOT natural ligands that bind to G protein-coupled receptors? a) hormones b) neurotransmitters c) chemoattractants d) opium derivatives e) steroid hormones Answer: e Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

20) For many years, _______ was the only member of the GPCR superfamily to have its X-ray crystal structure determined. a) rhodopsin b) the steroid receptor c) the insulin receptor d) the glucagon receptor e) the endocrine receptor Answer: a Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

21) Why does rhodopsin have an unusually stable structure for a GPCR? a) Its ligand is permanently bound to the protein. b) A retinal group is permanently bound to the protein. c) The protein molecule can only exist in a single conformation in the absence of a stimulus. d) The protein molecule can only exist in a single conformation in the dark. e) All of these are correct.

Answer: e Difficulty: Medium Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

22) Place the events of G protein activation in the correct order: 1) G protein binds to activated receptor forming a receptor-G protein complex 2) Release of GDP by the G protein 3) Change in conformation of the cytoplasmic loops of the receptor 4) Binding of GTP by the G protein 5) Increase in the affinity of the receptor for a G protein on the cytoplasmic surface of the membrane.

6) Binding of a hormone or neurotransmitter to a G-protein coupled receptor 7) Conformational shift in the α subunit of the G protein a) 6 – 3 – 5 – 1 – 2 – 4 – 7 b) 3 – 6 – 5 – 1 – 7 – 2 – 4 c) 6 – 3 – 5 – 1 – 7 – 2 – 4 d) 6 – 7 – 3 – 5 – 1 – 2 – 4 e) 6 – 3 – 5 – 1 – 7 – 4 – 2 Answer: c Difficulty: Hard Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

23) The subunits of the heterotrimeric G protein are called ___________ subunits. a) α, β and ε b) α, ɤ and ε c) α, β and ɤ d) α, ɤ and δ e) α, ɤ and η Answer: c Difficulty: Easy

Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

24) Where is the guanine nucleotide-binding site of the G protein located? a) on the Gα subunit b) on the Gβsubunit c) on the Gɤ subunit d) on the Gεsubunit e) on all three subunits Answer: a Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

25) Place the events for G protein response in the correct order.

1) Activation of one or more cellular signaling proteins.

2) Dissociation of Gαfrom the G protein complex.

3) Production of a second messenger, like cAMP. 4) Replacement of GDP by GTP on the Gα after interaction with an activated GPCR. 5) Conformational change in the Gα subunit causing a decreased affinity for the Gβɤsubunit.

6) Gα-subunit with its attached GTP activates an effector like adenylyl cyclase. a) 4 – 5 – 2 – 6 – 3 – 1 b) 5 – 4 – 2 – 6 – 3 – 1 c) 4 – 6 – 2 – 5 – 3 – 1 d) 4 – 5 – 2 – 3 – 1 – 6 e) 1 – 5 – 2 – 4 – 3 – 6 Answer: a Difficulty: Hard Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

26) Which heterotrimeric G proteins couple receptors to adenylyl cyclase via the activation of GTP-bound Gα subunits? a) Gs family b) Gq family c) Gi family d) G12/13 family e) Gr family Answer: a Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

27) Which heterotrimeric G proteins function by inhibiting adenylyl cyclase? a) Gs family b) Gq family c) Gi family d) G12/13family e) Gr family Answer: c Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

28) Which heterotrimeric G proteins are less well characterized than the other G protein families and are associated with excessive cell proliferation and malignant transformations when activated inappropriately? a) Gs family b) Gq family c) Gi family d) G12/13 family e) Gr family Answer: d

Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

29) The process that blocks active receptors from turning on additional G proteins is called ________. a) hypersensitization b) desensitization c) hyposensitization d) deactivation e) sensitivitization Answer: b Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

30) In order to begin desensitization, the ________ domain of the activated G protein-coupled receptor is phosphorylated by a specific enzyme called a ________. a) extracellular, G protein-coupled receptor kinase b) extracellular, G protein-coupled receptor phosphatase c) cytoplasmic, G protein-coupled receptor kinase d) cytoplasmic, G protein-coupled receptor phosphatase e) extracellular, GRK Answer: c Difficulty: Medium Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

31) GRKs are a small family of ________ protein kinases, most of which are localized to the _______ surface of the plasma membrane.

a) serine-threonine, cytoplasmic b) serine-threonine, extracellular c) tyrosine, cytoplasmic d) tyrosine, extracellular e) serine-tyrosine, cytoplasmic Answer: a Difficulty: Medium Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

32) What recruits cytoplasmic GRKs (G protein-coupled receptor kinases) to the plasma membrane? a) inhibition of certain G proteins b) destruction of the GPCRs c) activation of GPCRs d) inhibition of the GPCRs e) destruction of the hormone Answer: c Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

33) ________ are a small group of proteins that bind to GPCRs and compete for binding to those GPCRs with heterotrimeric G proteins. a) Stablins b) Arrestins c) Monomeric G proteins d) G protein-coupled receptor kinases e) Desensitizers Answer: b Difficulty: Easy

Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

34) Arrestin binding to GPCRs __________. a) causes the binding of additional G proteins b) prevents further activation of additional G proteins c) causes denaturation of G proteins d) stabilizes G proteins e) stabilizes GPCRs Answer: b Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

35) While bound to phosphorylated GPCRs, to what else can arrestins bind? a) G proteins b) clathrin molecules in clathrin-coated pits c) other arrestins d) hormones e) GRKs Answer: b Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

36) What does the interaction between arrestin and clathrin promote? a) the uptake of free hormone b) the uptake of phosphorylated GPCRs into the cell by exocytosis c) the uptake of phosphorylated GPCRs into the cell by endocytosis d) the expulsion of phosphorylated GPCRs from the cell by exocytosis

e) the secretion of GPCRs Answer: c Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

37) What happens to cells if receptors are degraded once they are internalized? a) The cells are able to make a magnified response to the same stimulus from the ligand in question. b) The cells permanently lose sensitivity for the ligand in question. c) The cells temporarily lose sensitivity for the ligand in question. d) The cells remain sensitive to the ligand in question. e) The cells expand.

Answer: c Difficulty: Medium Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

38) How is signaling by an activated Gα subunit terminated? a) The bound GTP is hydrolyzed to GMP. b) The bound GDP is hydrolyzed to GTP. c) The bound GTP is hydrolyzed to GDP. d) The bound GDP is phosphorylated to GTP. e) The Gα subunit releases GDP and binds GTP. Answer: c Difficulty: Medium Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

39) What role does carbon number 1 of the inositol ring of phosphatidylinositol play? a) It binds to steroid receptors. b) It links inositol to diacylglycerol. c) It links a phosphate group to diacyglycerol. d) It links glucose to diacylglycerol. e) It links two diacyglycerol molecules together.

Answer: b Difficulty: Medium Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

40) What group of enzymes phosphorylates most of the carbons on inositol? a) phospholipases b) phosphoinositide kinases c) phosphorylases d) phosphodiesterases e) phosphatases Answer: b Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

41) Which of the enzymes below does diacylglycerol (DAG) recruit and activate? a) phosphatidylinositol (PI)-specific phospholipase C-β b) protein kinase A c) protein kinase C d) glycogen phosphorylase e) phosphorylase kinase Answer: c Difficulty: Easy

Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

42) In what form do animal cells store glucose? a) glucogen b) glycogen c) agarose d) amylose e) amylopectin Answer: b Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

43) Which cells secrete epinephrine? a) α-cells in the pancreas b) β-cells in the pancreas c) ɤ-cells in the pancreas d) cortical cells in the adrenal gland e) medullary cells in the adrenal gland Answer: e Difficulty: Medium Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

44) Which hormone is secreted by β-cells in the pancreas in response to low blood glucose levels? a) insulin b) glycogen c) glucagon

d) epinephrine e) somatostatin Answer: c Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

45) What might cause a person to have an inability to detect a particular chemical in the environment that most other members of the population can perceive? a) mutations is a specific gene encoding the odorant receptor for that particular chemical b) mutations in the genes for all odorant molecules c) mutations in the genes for G proteins d) mutations in the genes for neurotransmitters e) mutations in the gene for one neurotransmitter Answer: a Difficulty: Medium Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

46) Perception of sour tastes depends upon _________. a) a compound interacting with a G protein coupled receptor on the receptor cell surface b) sodium ions in the food that enter H+ ion channels in the taste receptor plasma membrane, leading to a membrane depolarization c) protons in the food that enter cation channels in the taste receptor plasma membrane, leading to a membrane depolarization d) potassium ions in the food that enter cation channels in the taste receptor plasma membrane, leading to a membrane depolarization e) protons in the food that enter cation channels in the taste receptor plasma membrane, leading to a membrane hyperpolarization Answer: c Difficulty: Medium

Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

47) How many high-affinity sweet-taste receptors have been identified? a) none b) 30 c) 1 d) 10 e) 3 Answer: c Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

48) Where are the olfactory receptor cells located? a) the brain b) the nasal septum c) the upper nasal mucosa d) the surface of the tongue e) the nasal serosa Answer: c Difficulty: Easy Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

49) Why do colds cause us to lose some of our appreciation for the taste of food? a) The symptoms of colds interfere with the stimuli reaching the taste bud receptors, thus dulling the perception of taste. b) The symptoms of colds prevent stimuli from reaching olfactory neurons efficiently, thus dulling the perception of taste.

c) Cold viruses raise the firing threshold of olfactory neurons, thus dulling the perception of taste. d) Cold viruses lower the firing threshold of olfactory neurons, thus dulling the perception of taste. e) Cold viruses denature olfactory neurons, thus dulling the perception of taste.

Answer: b Difficulty: Hard Learning Objective: LO 15.3 Explain the role of G-protein coupled receptors within a signaling pathway.

Section Reference: Section 15.3 G Protein-Coupled Receptors and Their Second Messengers

50) Which of the following is NOT currently an application for biosensors? a) monitoring of blood glucose levels b) detection of pollutants in the environment c) detection of contaminants in the foods we eat d) indicator of food spoilage microbes in the air Answer: d Difficulty: Easy Learning Objective: LO 15.4 Identify the applications of biosensors in medicine and biology.

Section Reference: Section 15.4 Engineering Linkage: Biosensors in Medicine and Biology

51) Which characteristic below is essential for a biosensor to function effectively? a) ability to detect a wide range of similar chemicals as a single input b) fluctuation of accuracy as environmental conditions vary c) stability in the face of environmental factors such as temperature fluctuations d) ability to detect chemicals only when they are present in large concentrations Answer: c Difficulty: Medium Learning Objective: LO 15.4 Identify the applications of biosensors in medicine and biology.

Section Reference: Section 15.4 Engineering Linkage: Biosensors in Medicine and Biology

52) The size of a biosensor can be:

a) at the molecular level, such as a protein-based GPCR receptor signal monitor b) device-sized, like a blood glucose level detector c) cell-based to detect human and plant pathogens d) all choices are correct Answer: d Difficulty: Medium Learning Objective: LO 15.4 Identify the applications of biosensors in medicine and biology.

Section Reference: Section 15.4 Engineering Linkage: Biosensors in Medicine and Biology

53) _________ are enzymes that phosphorylate specific tyrosine residues on protein substrates. a) Protein tyrosinases b) Protein-tyrosine kinases c) Tyrosine pronases d) Proteokinases e) Tyrokinases Answer: b Difficulty: Easy Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

54) Which of the following features is a requirement for ligand-mediated dimerization? a) The ligand has only one binding site for receptors. b) The ligand has two binding sites for receptors. c) The receptor must have a phenylalanine residue in a specific location. d) The receptor must have a molecular weight of 50,000 daltons. e) Ligand binding causes a conformational shift that reveals a binding site for another receptor.

Answer: b Difficulty: Medium Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

55) Which of the following supports the ligand-mediated model of receptor dimerization? a) Some growth and differentiation factors like PDGF or CSF-1 are composed of two similar or identical disulfide-linked subunits, each of which has a binding site for a receptor. b) Ligands have been found to be proteins that usually dimerize. c) Ligands have been found to be steroid hormones. d) Ligands were found to bind to each other. e) Receptors have been shown to have multiple binding sites for ligands.

Answer: a Difficulty: Medium Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

56) Which statement below is an accurate description of receptor-mediated dimerization? a) Ligands act as allosteric regulators that turn on the ability of their receptors to form dimers. b) Ligands act as allosteric inhibitors that turn on the ability of their receptors to form dimers. c) Ligands act as allosteric inhibitors that turn off the ability of their receptors to form dimers. d) Ligands act as allosteric regulators that turn off the ability of their receptors to form dimers. e) Ligands act as bridging factors that allow the receptors to dimerize.

Answer: a Difficulty: Medium Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

57) Once the kinase domain of receptor protein-tyrosine kinase has been activated, what does the activated receptor protein-tyrosine kinase do? a) The receptor subunits denature.

b) Each receptor subunit phosphorylates its partner on tyrosine residues found in regions adjacent to the kinase domain. c) Each receptor subunit phosphorylates itself on tyrosine residues found in regions adjacent to the kinase domain. d) The receptor subunits dephosphorylate each other. e) The receptor subunits refold into a more effective conformation.

Answer: b Difficulty: Medium Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

58) What event is usually responsible for terminating signal transduction by RTKs? a) dephosphorylation of the receptor b) degradation of the ligand c) receptor internalization d) phosphorylation of the receptor e) acetylation of the receptor Answer: c Difficulty: Easy Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

59) Viruses that carry their genetic information in the form of RNA are called ________. a) viria b) retroviruses c) reverse transcriptases d) retrons e) provirions Answer: b Difficulty: Easy

Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

60) Genes that enable viruses to transform normal cells into tumor cells are called _________. a) oncogenes b) cancogenes c) haplogenes d) tumor enhancer genes e) transformer genes Answer: a Difficulty: Easy Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

61) What kind of enzyme activity does the Ras protein display? a) ATPase b) kinase c) phosphodiesterase d) GTPase e) phosphatase Answer: d Difficulty: Easy Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

62) What holds Ras at the inner surface of the plasma membrane? a) weak interactions with the phospholipid head groups

b) weak interactions with integral membrane proteins c) hydrophilic interactions of the Ras protein with the interior of the phospholipid bilayer d) attachment to a lipid group that is embedded in the inner leaflet of the bilayer e) attachment to a carbohydrate group that is embedded in the inner leaflet of the bilayer Answer: d Difficulty: Medium Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

63) How is Ras activity turned off? a) It is turned off by phosphorylation. b) It is turned off by hydrolysis of its bound GTP to GDP. c) It is turned off by hydrolysis of its bound GDP to GTP. d) It is turned off by an allosteric inhibitor. e) It is turned off by hydrolysis of its bound GTP to GMP. Answer: b Difficulty: Easy Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

64) Accessory proteins that bind to inactive monomeric G proteins and stimulate dissociation of the bound GDP are called: a) GAPs b) GEFs c) GDIs d) RASps e) MAPs Answer: b Difficulty: Easy

Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

65) Accessory proteins that maintain monomeric G proteins in an inactive state by inhibiting GDP-GTP exchange are called: a) GAPs b) GEFs c) GDIs d) RASps e) MAPs Answer: c Difficulty: Easy Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

66) In cells exposed to stressful stimuli, like X-rays or damaging chemicals, what response does the MAP kinase cascade coordinate? a) cell proliferation b) withdrawal from the cell cycle c) rapid differentiation d) slowing of the Krebs cycle e) a loss of sensory ability Answer: b Difficulty: Medium Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

67) What is the reason for the withdrawal of cells from the cell cycle after exposure to stressful stimuli, like X-rays and damaging chemicals? a) It gives the cell time to repair damage resulting from such adverse conditions. b) It allows the cell to initiate programmed cell death. c) It allows cells to initiate sodium transport. d) It allows the cell to secrete defensive chemicals. e) It gives the cell time to switch its developmental pathways.

Answer: a Difficulty: Medium Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

68) Specificity in MAP kinase pathways is sometimes achieved by spatial localization of the pathway's component proteins. Spatial localization of these components is done by structural (i.e., nonenzymatic) proteins called _____________. a) sequestration proteins b) partitioning proteins c) scaffolding proteins d) framework proteins e) spatial organization proteins Answer: c Difficulty: Easy Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

69) Two αβ heterodimers of the insulin receptor are held together by ____ between the _______. a) ionic bonds, α chains b) ionic bonds, β chains c) disulfide bonds, α chains d) disulfide bonds, β chains e) disulfide bonds, α chain of one heterodimer and the β chain of the other

Answer: c Difficulty: Medium Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

70) What part of an insulin-receptor substrate binds to tyrosine phosphorylation sites on the activated insulin receptor? a) an N-terminal PH domain b) a phosphotyrosine binding domain c) a long tail containing tyrosine phosphorylation sites d) a C-terminal PH domain e) a PKB domain Answer: b Difficulty: Medium Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

71) The enzyme that has been identified as a negative regulator of glycogen synthase is ______. a) glycogen phosphorylase b) glycogen phosphorylase kinase c) glycogen synthase kinase-3 d) insulin synthase kinase e) protein kinase A Answer: c Difficulty: Easy Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

72) What is responsible for deactivating glycogen synthase kinase-3? a) phosphorylation by PKB b) dephosphorylation by protein phosphatase 1 c) dephosphorylation by PKB d) phosphorylation by protein phosphatase 1 e) degradation by PKB Answer: a Difficulty: Hard Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

73) Type I diabetes is caused by ________. a) degradation of insulin in the bloodstream b) an inability to produce insulin c) a decrease in the ability of target cells for insulin to respond to the presence of the hormone d) insulin resistance e) an overproduction of insulin Answer: b Difficulty: Easy Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

74) Which of the following signaling methods is absent in plants but present in other eukaryotes? a) MAP kinase pathway b) Ca2+ signaling c) phosphoinositide signaling d) cyclic nucleotides e) extracellular receptors

Answer: d Difficulty: Medium Learning Objective: LO 15.5 Describe how protein-tyrosine kinases function in a variety of signal transduction pathways.

Section Reference: Section 15.5 Protein-Tyrosine Phosphorylation as a Mechanism for Signal Transduction

75) Who was one of the first scientists to observe the effects of the plant hormone auxin? a) Gregor Mendel b) Charles Darwin c) Louis Pasteur d) Barbara McClintock Answer: b Difficulty: Easy Learning Objective: LO 15.6 Describe the role of auxin signaling in plant growth and development.

Section Reference: Section 15.6 Green Cells: Auxin Signaling

76) Which was NOT an observation made in the initial experiments that revealed effects of auxin signaling? a) grass seedlings exposed to overhead light bent towards the darkest region of their environment b) grass seedlings whose blade tips were removed could not exhibit movement or bending c) grass seedlings exposed to laterally-placed light bent towards the light source d) grass seedlings tips and bases behaved differently in response to light stimulus Answer: a Difficulty: Medium Learning Objective: LO 15.6 Describe the role of auxin signaling in plant growth and development.

Section Reference: Section 15.6 Green Cells: Auxin Signaling

77) The auxin response factor (ARF) family members are believed to encode _______________. a) G proteins

b) ubiquitins c) transcription factors d) gene repressors Answer: c Difficulty: Medium Learning Objective: LO 15.6 Describe the role of auxin signaling in plant growth and development.

Section Reference: Section 15.6 Green Cells: Auxin Signaling

78) The concentration of calcium ions in the ER lumen, the plant cell vacuole and the extracellular space are on average more than _______ times higher than in the cytosol. a) 10 b) 100 c) 1,000 d) 10,000 e) 1,000,000 Answer: d Difficulty: Easy Learning Objective: LO 15.7 Explain how calcium and calmodulin function as intracellular messengers in cell signaling.

Section Reference: Section 15.7 The Role of Calcium as an Intracellular Messenger

79) Following a nerve impulse, what triggers the opening of plasma membrane voltage-gated Ca2+ channels? a) membrane hyperpolarization b) binding of an appropriate ligand c) membrane depolarization d) membrane hypopolarization e) binding of K+ ions Answer: c Difficulty: Easy Learning Objective: LO 15.7 Explain how calcium and calmodulin function as intracellular messengers in cell signaling.

Section Reference: Section 15.7 The Role of Calcium as an Intracellular Messenger

80) How is the distribution of free calcium ions in the living cell detected? a) fluorescent probes that emit light in the presence of calcium ions b) antibodies bound to ferritin c) an electron microscope d) autoradiography and the distribution of radioisotope e) NMR imaging Answer: a Difficulty: Easy Learning Objective: LO 15.7 Explain how calcium and calmodulin function as intracellular messengers in cell signaling.

Section Reference: Section 15.7 The Role of Calcium as an Intracellular Messenger

81) What generally triggers the release of calcium ions by ryanodine receptors? a) potassium efflux b) sodium influx c) an action potential d) IP3 release e) IP3 uptake Answer: c Difficulty: Easy Learning Objective: LO 15.7 Explain how calcium and calmodulin function as intracellular messengers in cell signaling.

Section Reference: Section 15.7 The Role of Calcium as an Intracellular Messenger

82) Among the agents that can cause ryanodine receptors to open are _______ ions, in a phenomenon called _______. a) calcium, calcium-integrated calcium release b) calcium, calcium-induced calcium release c) potassium, potassium-induced calcium release d) chlorine, chlorine-induced calcium release e) copper, copper-induced calcium release

Answer: b Difficulty: Medium Learning Objective: LO 15.7 Explain how calcium and calmodulin function as intracellular messengers in cell signaling.

Section Reference: Section 15.7 The Role of Calcium as an Intracellular Messenger

83) What is activated by calcium ions entering an egg cell just after fertilization? a) protein kinase A b) insulin c) cyclin-dependent kinases that drive the zygote toward its first mitotic division d) cyclin-dependent kinases that drive the zygote toward its first meiotic division e) glucagon-dependent kinases that drive the zygote toward its first mitotic division Answer: c Difficulty: Medium Learning Objective: LO 15.7 Explain how calcium and calmodulin function as intracellular messengers in cell signaling.

Section Reference: Section 15.7 The Role of Calcium as an Intracellular Messenger

84) What can cause the stockpiles of intracellular calcium ions to be depleted? a) periods of repeated cellular responses b) a paucity of cellular responses c) crystallization of calcium ions with chlorine ions d) crystallization of calcium with phosphate ions Answer: a Difficulty: Medium Learning Objective: LO 15.7 Explain how calcium and calmodulin function as intracellular messengers in cell signaling.

Section Reference: Section 15.7 The Role of Calcium as an Intracellular Messenger

85) Orai1 is a tetrameric _______ that has been identified as being involved in a particular type of inherited human immune deficiency that results from a lack of Ca2+ stores in ________.

a) Ca2+ ion channel, B lymphocytes b) Ca2+ ion pump, B lymphocytes c) Ca2+ ion channel, T lymphocytes d) Ca2+ ion pump, T lymphocytes e) Ca2+ ion channel, macrophages Answer: c Difficulty: Medium Learning Objective: LO 15.7 Explain how calcium and calmodulin function as intracellular messengers in cell signaling.

Section Reference: Section 15.7 The Role of Calcium as an Intracellular Messenger

86) What is the name of a calcium-binding protein that acts in conjunction with calcium to bring about the responses associated with cytoplasmic rises in calcium ion concentration? a) calpectin b) calmodulin c) calcariain d) callistin e) modulocalcin Answer: b Difficulty: Easy Learning Objective: LO 15.7 Explain how calcium and calmodulin function as intracellular messengers in cell signaling.

Section Reference: Section 15.7 The Role of Calcium as an Intracellular Messenger

87) In which organism below has calmodulin not been found? a) plants b) animals c) bacteria d) yeasts e) humans Answer: c Difficulty: Easy Learning Objective: LO 15.7 Explain how calcium and calmodulin function as intracellular messengers in cell signaling.

Section Reference: Section 15.7 The Role of Calcium as an Intracellular Messenger

88) Why does calcium not bind to calmodulin in a non-stimulated cell? a) Calmodulin's affinity for calcium ions is too low to allow binding in a nonstimulated cell. b) Calmodulin's affinity for calcium ions is too high to allow binding in a nonstimulated cell. c) In a nonstimulated cell, calcium ions are destroyed. d) In a nonstimulated cell, calcium ions are produced. e) In a nonstimulated cell, calcium ions preferentially bind to another protein in the cytosol.

Answer: a Difficulty: Medium Learning Objective: LO 15.7 Explain how calcium and calmodulin function as intracellular messengers in cell signaling.

Section Reference: Section 15.7 The Role of Calcium as an Intracellular Messenger

89) The activation of a common effector by signals from a variety of unrelated receptors, each of which binds to its own ligand, is called _________. a) divergence b) convergence c) cross-talk d) transvergence e) coherence Answer: b Difficulty: Easy Learning Objective: LO 15.8 Identify the roles of divergence, convergence, and cross-talk in cell signaling pathways.

Section Reference: Section 15.8 Convergence, Divergence, and Cross-Talk Among Different Signaling Pathways

90) The passage of signals back and forth between different pathways is referred to as _________. a) divergence b) convergence c) cross-talk

d) transvergence e) coherence Answer: c Difficulty: Easy Learning Objective: LO 15.8 Identify the roles of divergence, convergence, and cross-talk in cell signaling pathways.

Section Reference: Section 15.8 Convergence, Divergence, and Cross-Talk Among Different Signaling Pathways

91) What molecule is responsible for activating Rsk-2? a) PKA b) CREB c) MAPKK d) MAPK e) cAMP Answer: d Difficulty: Easy Learning Objective: LO 15.8 Identify the roles of divergence, convergence, and cross-talk in cell signaling pathways.

Section Reference: Section 15.8 Convergence, Divergence, and Cross-Talk Among Different Signaling Pathways

92) Which inorganic gas has been shown to act as a second messenger that relaxes the smooth muscles of blood vessels? a) NO b) N2O c) nitrous oxide d) CO e) N2 Answer: a Difficulty: Easy Learning Objective: LO 15.9 Describe how nitric oxide mediates dilation of blood vessels.

Section Reference: Section 15.9 The Role of NO as an Intercellular Messenger

93) _____ is formed from the amino acid L-______ in a reaction catalyzed by the enzyme _____. a) Nitrous oxide, arginine, nitrous oxide synthase b) Nitric oxide, asparagine, nitric oxide synthase c) Nitric oxide, alanine, nitric oxide synthase d) Nitric oxide, arginine, nitric oxide synthase e) Nitrous oxide, arginine, nitric oxide synthase Answer: d Difficulty: Medium Learning Objective: LO 15.9 Describe how nitric oxide mediates dilation of blood vessels.

Section Reference: Section 15.9 The Role of NO as an Intercellular Messenger

94) Why did the smooth muscle in cultured strips of aorta not respond to acetylcholine by relaxing, while the smooth muscle of aortic rings did? a) Smooth muscle cells in aortic strips are physically incapable of relaxing under any circumstances. b) Acetylcholine in the strips could not penetrate to the muscle cells while in the rings it could. c) Smooth muscle cells in aortic rings express acetylcholine receptors, while those in strips do not. d) The delicate endothelial layer in aortal strips had been rubbed away during dissection, while in aortal rings it remained intact. e) The endothelial layer in aortal strips was abnormally thickened, while in aortal rings it was not.

Answer: d Difficulty: Medium Learning Objective: LO 15.9 Describe how nitric oxide mediates dilation of blood vessels.

Section Reference: Section 15.9 The Role of NO as an Intercellular Messenger

95) In which of the following biological processes is nitric oxide not involved? a) anticoagulation b) neurotransmission c) smooth muscle relaxation d) visual perception e) hearing

Answer: e Difficulty: Easy Learning Objective: LO 15.9 Describe how nitric oxide mediates dilation of blood vessels.

Section Reference: Section 15.9 The Role of NO as an Intercellular Messenger

96) What agent made by endothelial cells makes blood vessel smooth muscle cells relax? a) nitrous oxide b) acetylcholine c) nitric oxide d) cAMP e) cGMP Answer: c Difficulty: Easy Learning Objective: LO 15.9 Describe how nitric oxide mediates dilation of blood vessels.

Section Reference: Section 15.9 The Role of NO as an Intercellular Messenger

97) What stimulus triggered by the binding of acetylcholine then activates nitric oxide synthase? a) a rise in cytoplasmic Ca2+ concentration b) a drop in cytoplasmic Ca2+ concentration c) an action potential d) cellular hyperpolarization e) release of cGMP Answer: a Difficulty: Easy Learning Objective: LO 15.9 Describe how nitric oxide mediates dilation of blood vessels.

Section Reference: Section 15.9 The Role of NO as an Intercellular Messenger

98) How were nitroglycerine's therapeutic benefits discovered? a) through careful drug testing b) the fact that dynamite factory workers with heart conditions had less angina on days that they worked

c) the fact that dynamite factory workers with heart conditions had more angina on days that they worked d) by reading the literature Answer: b Difficulty: Easy Learning Objective: LO 15.9 Describe how nitric oxide mediates dilation of blood vessels.

Section Reference: Section 15.9 The Role of NO as an Intercellular Messenger

99) How does Viagra enhance erectile function of the penis? a) by inhibiting nitric oxide release b) by inhibiting guanylyl cyclase activity c) by preventing cGMP production d) by inhibiting cGMP phosphodiesterase e) by inhibiting cGMP phosphatase Answer: d Difficulty: Medium Learning Objective: LO 15.9 Describe how nitric oxide mediates dilation of blood vessels.

Section Reference: Section 15.9 The Role of NO as an Intercellular Messenger

100) To which amino acid is nitric oxide added, altering the activity, turnover and/or interactions of proteins like hemoglobin, Ras, ryanodine channels and caspases? a) alanine b) cysteine c) methionine d) asparagine e) phenylalanine Answer: b Difficulty: Easy Learning Objective: LO 15.9 Describe how nitric oxide mediates dilation of blood vessels.

Section Reference: Section 15.9 The Role of NO as an Intercellular Messenger

101) How does the immune system manage to avoid recognizing and attacking normal cells within the body? a) The body never makes T lymphocytes that can react against normal cells within the body. b) T lymphocytes that have the ability to recognize normal cells within the body are eliminated by apoptosis early in the development of the immune system. c) Normal body cells are coated with a special secreted protective proteoglycan that prevents the immune system from attacking them. d) Normal body cells are coated with a special secreted protective glycoprotein that prevents the immune system from attacking them. e) Normal body cells are coated with a mixture of special secreted protective proteoglycans and glycoproteins that prevents the immune system from attacking them.

Answer: b Difficulty: Medium Learning Objective: LO 15.10 Differentiate necrosis from the extrinsic and intrinsic pathways of apoptosis.

Section Reference: Section 15.10 Apoptosis (Programmed Cell Death)

102) Which gene in C. elegans was found to play a critical role in apoptosis? a) CED-3 b) DEG-3 c) NSO-1 d) Eco R1 e) CEL-3 Answer: a Difficulty: Easy Learning Objective: LO 15.10 Differentiate necrosis from the extrinsic and intrinsic pathways of apoptosis.

Section Reference: Section 15.10 Apoptosis (Programmed Cell Death)

103) A family of proteins homologous to the products of the CED-3 gene in C. elegans has been discovered in mammals. What is this family of proteins called? a) capsidases b) caspases c) capsasins d) capsulases

e) apoptases Answer: b Difficulty: Easy Learning Objective: LO 15.10 Differentiate necrosis from the extrinsic and intrinsic pathways of apoptosis.

Section Reference: Section 15.10 Apoptosis (Programmed Cell Death)

104) How is caspase-activated DNase (CAD) activated? a) A caspase cleaves CAD, activating it. b) A caspase cleaves an activator of CAD, turning it on and causing it to activate CAD. c) A caspase cleaves a CAD inhibitor, relieving the CAD of inhibition. d) A caspase binds to CAD allosterically, activating it. e) None of these are correct.

Answer: c Difficulty: Easy Learning Objective: LO 15.10 Differentiate necrosis from the extrinsic and intrinsic pathways of apoptosis.

Section Reference: Section 15.10 Apoptosis (Programmed Cell Death)

105) The _________ pathway of apoptosis is one in which external stimuli activate apoptosis via a signaling pathway. a) extrinsic b) external c) intrinsic d) peripheral e) integral Answer: a Difficulty: Easy Learning Objective: LO 15.10 Differentiate necrosis from the extrinsic and intrinsic pathways of apoptosis.

Section Reference: Section 15.10 Apoptosis (Programmed Cell Death)

106) The _________ pathway of apoptosis is one in which internal stimuli activate apoptosis. a) extrinsic b) external c) intrinsic d) peripheral e) integral Answer: c Difficulty: Easy Learning Objective: LO 15.10 Differentiate necrosis from the extrinsic and intrinsic pathways of apoptosis.

Section Reference: Section 15.10 Apoptosis (Programmed Cell Death)

107) What is the name of the extracellular messenger protein with an ability to kill tumor cells that also serves as an apoptotic stimulus? a) tumor angiogenesis factor b) tumor death factor c) tumor necrosis factor d) necromancer factor e) tumorigenic factor Answer: c Difficulty: Easy Learning Objective: LO 15.10 Differentiate necrosis from the extrinsic and intrinsic pathways of apoptosis.

Section Reference: Section 15.10 Apoptosis (Programmed Cell Death)

108) Evidence suggests that TNFR1 is present in the plasma membrane as __________. a) a preassembled trimer b) a preassembled dimer c) a disassembled trimer d) a disassembled dimer e) a tetrameric trimer Answer: a Difficulty: Easy

Learning Objective: LO 15.10 Differentiate necrosis from the extrinsic and intrinsic pathways of apoptosis.

Section Reference: Section 15.10 Apoptosis (Programmed Cell Death)

109) Each TNFR1 receptor subunit has a cytoplasmic domain with a segment of about 70 amino acids that mediates protein-protein interactions. This domain of the receptor is referred to as the ______ domain. a) central b) morte c) death d) terminal e) cytoplasmic Answer: c Difficulty: Easy Learning Objective: LO 15.10 Differentiate necrosis from the extrinsic and intrinsic pathways of apoptosis.

Section Reference: Section 15.10 Apoptosis (Programmed Cell Death)

110) Bcl-2 acts as ________ by promoting ___________. a) an oncogene, cell division b) a haplogene, survival of potential cancer cells that would otherwise die by apoptosis c) an oncogene, survival of potential cancer cells that would otherwise die by apoptosis d) a cancer gene, survival of potential cancer cells that would otherwise die by apoptosis e) a haplogene, cell division Answer: c Difficulty: Medium Learning Objective: LO 15.10 Differentiate necrosis from the extrinsic and intrinsic pathways of apoptosis.

Section Reference: Section 15.10 Apoptosis (Programmed Cell Death)

111) Once activated, what does caspase-9 itself activate? a) phospholipase C b) protein kinase A

c) other initiator caspases d) downstream executioner caspases e) downstream caspase-8 Answer: d Difficulty: Easy Learning Objective: LO 15.10 Differentiate necrosis from the extrinsic and intrinsic pathways of apoptosis.

Section Reference: Section 15.10 Apoptosis (Programmed Cell Death) Question Type: Multiple Select

112) Proteins interact with one another, or with components of the cellular membrane, by means of _________. (Select all correct choices) a) specific types of interaction domains b) intercellular glue c) the SH3 domain d) peptide bonds Answer: a, c Difficulty: Medium Learning Objective: LO 15.1 Explain the role of each of the key molecules involved in signal transduction.

Section Reference: Section 15.1 The Basic Elements of Cell Signaling Systems

Question Type: Multiple Select

113) Most protein kinases commonly transfer phosphate groups to which amino acid(s)?

(Select all correct choices) a) glutamate b) threonine c) serine d) tryptophan Answer: b, c

Difficulty: Medium Learning Objective: LO 15.1 Explain the role of each of the key molecules involved in signal transduction.

Section Reference: Section 15.1 The Basic Elements of Cell Signaling Systems

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 16

Question Type: Multiple Choice

1) When resources are limited, normal cells in culture will exhibit decreased growth rates. Which statement does NOT describe how cancer cells will respond? a) They continue to grow and divide. b) They pile on top of one another forming clumps. c) Their growth rate decreases. d) They fail to respond to the types of signals that cause normal cells to cease growth and division.

Answer: c Difficulty: Medium Learning Objective: LO 16.1 Differentiate a cancer cell from a normal cell.

Section Reference: Section 16.1 Basic Properties of a Cancer Cell

2) What generally happens if cells that have been transformed into cancer cells in culture by carcinogenic chemicals or viruses are introduced into a host animal? a) Nothing happens; they do not survive the introduction process. b) They are reconverted to normal cells in the host. c) They generally cause tumors in the host animal. d) The host animal's immune system destroys the transformed cancer cells.

Answer: c Difficulty: Easy Learning Objective: LO 16.1 Differentiate a cancer cell from a normal cell.

Section Reference: Section 16.1 Basic Properties of a Cancer Cell

3) What is the most important property of a cancer cell, whether it is in the body or in vitro? a) its chromosome complement

b) its loss of growth control c) its size d) its secretions e) its inability to divide Answer: b Difficulty: Easy Learning Objective: LO 16.1 Differentiate a cancer cell from a normal cell.

Section Reference: Section 16.1 Basic Properties of a Cancer Cell

4) Which statement below is a correct statement about the abilities of normal cells and cancer cells to grow and divide when cultured under conditions favorable for normal cell proliferation? a) Malignant cells grow and divide at a faster rate than normal cells. b) Normal cells grow and divide at a faster rate than malignant cells. c) Malignant and normal cells grow and divide at similar rates. d) Neither type of cell grows well. e) Normal cells do not grow at all, while malignant cells grow very rapidly.

Answer: c Difficulty: Medium Learning Objective: LO 16.1 Differentiate a cancer cell from a normal cell.

Section Reference: Section 16.1 Basic Properties of a Cancer Cell

5) A single layer of cells that covers a culture dish is called _________. a) a permalayer b) an imperium c) a monolayer d) a unilayer Answer: c Difficulty: Easy Learning Objective: LO 16.1 Differentiate a cancer cell from a normal cell.

Section Reference: Section 16.1 Basic Properties of a Cancer Cell

6) How can cancer cells proliferate in the absence of blood serum?

a) Their nuclei depend on these serum growth factors to maintain their structure. b) The serum inhibits their growth, while it is necessary for normal cells. c) The cell cycle of cancer cells does not depend on growth-factor from serum. d) The cell cycle of cancer cells depends on signals transmitted from serum growth-factor receptors located in their cytoplasm. e) Their mitochondria depend on serum growth factors for their activity.

Answer: c Difficulty: Medium Learning Objective: LO 16.1 Differentiate a cancer cell from a normal cell.

Section Reference: Section 16.1 Basic Properties of a Cancer Cell

7) What is the component called “serum” that is added to culture media? a) any sugary solution b) the fluid fraction of blood c) a particulate fraction of blood d) a combination of the fluid and particulate fractions of blood e) any blood that has been in a syringe Answer: b Difficulty: Easy Learning Objective: LO 16.1 Differentiate a cancer cell from a normal cell.

Section Reference: Section 16.1 Basic Properties of a Cancer Cell

8) What enzymatic activity is possessed by telomerase? a) It maintains centromeres at chromosome ends (telomeres). b) It degrades centromeres at the telomeres of chromosomes. c) It maintains telomeres at the ends of chromosomes. d) It degrades telomeres at the ends of chromosomes. e) It attaches telomeric regions of homologous chromosomes to each other.

Answer: c Difficulty: Medium Learning Objective: LO 16.1 Differentiate a cancer cell from a normal cell.

Section Reference: Section 16.1 Basic Properties of a Cancer Cell

9) The fact that tumor cells depend, in many cases, on glycolysis may reflect ________. a) the low metabolic requirements of cancer cells b) the high oxygen levels the cancer cells usually encounter c) an inadequate blood supply within the tumor d) mutations in glycolytic enzyme-encoding genes Answer: c Difficulty: Medium Learning Objective: LO 16.1 Differentiate a cancer cell from a normal cell.

Section Reference: Section 16.1 Basic Properties of a Cancer Cell

10) Hypoxic conditions ___________. a) cause cancer cells to activate a transcription factor called Hif b) can cause cancer cells to induce the formation of new blood vessels c) can promote the migratory properties of cancer cells d) can cause the spread of a tumor e) all of these are correct Answer: e Difficulty: Hard Learning Objective: LO 16.1 Differentiate a cancer cell from a normal cell.

Section Reference: Section 16.1 Basic Properties of a Cancer Cell

11) Who made the first known correlation between environmental agents and cancer development? a) Henry Potter b) Percivall Pott c) Percival Lowell d) Charles Darwin e) Archibald Garrod Answer: b Difficulty: Easy Learning Objective: LO 16.2 Describe potential causes of cancer.

Section Reference: Section 16.2 Causes of Cancer

12) What do all of the environmental agents that can cause cancer have in common? a) They can all alter the genome. b) They are all soluble in water. c) They are all made of nucleic acids. d) They are all made of amino acids. e) They all can alter proteins present in the cell cytoplasm that are responsible for the onset of cancer.

Answer: a Difficulty: Easy Learning Objective: LO 16.2 Describe potential causes of cancer.

Section Reference: Section 16.2 Causes of Cancer

13) Why do tumor viruses transform normal cells into cancer cells? a) They take over the normal cells and cause them to make progeny viruses. b) They carry genes whose products interfere with the cell's normal growth-regulating activities. c) They carry genes whose products interfere with the cell's normal bioenergetics pathways. d) They carry genes whose products interfere with the cell's normal secretory activities.

Answer: b Difficulty: Easy Learning Objective: LO 16.2 Describe potential causes of cancer.

Section Reference: Section 16.2 Causes of Cancer

14) What evidence suggests that while viruses may play a role in cancer development and increase a person's risk of developing cancer, they are rarely the sole determinant responsible for the disease? a) Human papilloma virus (HPV) is transmitted by sexual intercourse. b) Although HPV is found in ~90% of human cervical cancers, most women infected with the virus never develop the cancer. c) HPV is found in ~90% of human cervical cancers, and women infected with the virus develop the cancer. d) All women infected with HPV develop cervical cancer.

Answer: b Difficulty: Medium Learning Objective: LO 16.2 Describe potential causes of cancer.

Section Reference: Section 16.2 Causes of Cancer

15) Which one of the following viruses does NOT appear to be linked to human cancers? a) hepatitis B virus b) Epstein-Barr virus c) herpes virus HHV-8 d) SV40 e) rhinovirus Answer: e Difficulty: Medium Learning Objective: LO 16.2 Describe potential causes of cancer.

Section Reference: Section 16.2 Causes of Cancer

16) Chronic infection with which stomach-dwelling bacterium has been associated with certain gastric lymphomas? a) Escherichia coli b) Staphylococcus aureus c) Helicobacter pylori d) Saccharomyces cerevisiae Answer: c Difficulty: Easy Learning Objective: LO 16.2 Describe potential causes of cancer.

Section Reference: Section 16.2 Causes of Cancer

17) Cancer results from the uncontrolled proliferation of a single wayward cell and is therefore considered to be _________. a) polyclonal

b) biclonal c) monoclonal d) variant e) obstreperous Answer: c Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

18) Another word for malignant transformation is ________. a) oncologination b) ontogenesis c) cancerogenesis d) tumorigenesis e) oncogenation Answer: d Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

19) Which cells below possess unlimited proliferation potential, have the capacity to produce more of themselves, and can give rise to all of the cells of the tissue? a) stem cells b) progenitor cells c) differentiated end products of a tissue d) endocardial cells Answer: a Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

20) Which cells generally lack the ability to divide? a) stem cells b) progenitor cells c) differentiated end products of a tissue d) endocardial cells Answer: c Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

21) What enzyme is responsible for maintaining the length of the DNA sequences on the ends of chromosomes? a) tendrilase b) telomerase c) telomere synthase d) telomere disruptase e) telomere kinase Answer: b Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

22) When telomerase appears in a cell, it is not because the coding sequences of the gene have been mutated. Instead, the protein produced is essentially normal, but it is being produced at an abnormal time. A gene that is normally repressed has been activated for some reason. Such an alteration in DNA structure is referred to as _________ change. a) an androgenous b) a mutational c) an epigenetic d) a structural e) an ancillary

Answer: c Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

23) Scientists in the late 1960’s were studying two rodent cell lines, one malignant and one normal. In an experiment which fused malignant and normal cells, what happened? a) All of the hybrid (fused) cells behaved like malignant cancer cells. b) Some of the hybrid cells lost malignant traits. c) Some of the hybrid cells gained more extreme malignant traits. d) Most of the hybrids died shortly after fusion. e) The hybrids began to fuse together spontaneously making giant multinucleate cells.

Answer: b Difficulty: Hard Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

24) Using conventional nomenclature, which of the hypothetical genes named below would be a human gene? a) ABC b) Gef c) par d) Raf Answer: a Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

25) Using conventional nomenclature, which of the hypothetical genes named below would be a viral gene? a) ABC b) Gef c) par d) Raf Answer: c Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

26) Oncogenes are __________. a) eukaryotic cellular genes that were incorporated into the viral genome during a previous infection b) genes that originated in bacterial genomes c) genes that originated in viral genomes but are found in eukaryotic genomes d) genes that originated in bacterial genomes, moved to viral genomes and were eventually transferred to eukaryotes Answer: a Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

27) How have scientists historically identified oncogenes? a) by introducing the DNA suspected of containing the oncogene into cultured cells and looking for altered growth properties b) by fusing two normal cells together c) by fusing two malignant cells together d) by introducing the DNA suspected of containing the oncogene into cultured cells and looking for altered nuclear membranes Answer: a

Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

28) ____________ is a rare childhood cancer of the eye's retina. a) Retinal carcinoma b) Eye cancer c) Retinal sarcoma d) Retinoblastoma e) Retinal epithelioma Answer: d Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

29) Retinoblastoma is inherited as a ____________. a) dominant trait b) recessive trait c) sex-linked recessive trait d) sex-linked dominant trait e) codominant trait Answer: a Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

30) What is unusual about the inheritance of retinoblastoma, given that it appears to be inherited as a dominant trait? a) All children who inherit one copy of the RB deletion develop retinoblastoma. b) Not all children who inherit the RB deletion develop retinoblastoma.

c) No children who inherit the RB deletion develop retinoblastoma. d) Only boys appear to develop retinoblastoma. e) Only girls appear to develop retinoblastoma.

Answer: b Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

31) Cells from a retinoblastoma tumor are cultured and a wild-type copy of the gene is reintroduced into the cells. What is the result of this experiment? a) The cancer phenotype remains. b) The cancer phenotype is more extreme. c) The cancer phenotype disappears. d) The cells immediately die.

Answer: c Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

32) What part of the cell cycle does the pRB protein help to regulate? a) S to G2 transition b) G1 to S transition c) G2 to M transition d) G0 to G1 transition e) M to G2 transition Answer: b Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

33) Which of the following is true of healthy G1 cells? a) The p53 protein is found at very high levels. b) The probability of apoptosis in these cells is very high. c) The p53 protein is found at very low levels. d) All choices are correct.

Answer: c Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

34) What happens if a G1 cell sustains genetic damage? a) The p53 protein concentration rises very rapidly. b) There is no increased expression of the p53 gene. c) The p53 protein exhibits an increase in stability. d) All choices are correct.

Answer: d Difficulty: Hard Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

35) Put the following events in the correct order.

1) p53 is unable to bind to MDM2.

2) The expression of the p21 and BAX genes is activated.

3) ATM is activated.

4) DNA experiences damage from UV-light or chemotherapy drugs.

5) ATM phosphorylates p53.

6) p53 remains in the nucleus, instead of being transported into the cytosol. a) 4 – 5 – 3 – 1 – 6 – 2 b) 4 – 3 – 5 – 1 – 6 – 2 c) 4 – 3 – 5 – 2 – 1 – 6 d) 4 – 1 – 3 – 5 – 6 – 2 e) 3 – 5 – 4 – 1 – 6 – 2

Answer: b Difficulty: Hard Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

36) You study two cell lines. In one, the MDM2 protein is overexpressed; in the other the p53 protein is absent. What difference would you expect in the behavior of these two cell lines? a) In cells containing overexpressed MDM2, p53 levels will be low; in cells lacking the p53 protein, p53 levels are also low; thus there will be no difference in behavior. b) In cells containing overexpressed MDM2, p53 levels will be high; in cells lacking the p53 protein, p53 levels are low; thus there will be a drastic difference in behavior. c) In cells containing overexpressed MDM2, p53 levels will be high; in cells lacking the p53 protein, p53 levels are high; thus there will be no difference. d) In cells containing overexpressed MDM2, p53 levels will be low; in cells lacking the p53 protein, p53 levels are high; thus there will be no difference in behavior. e) None of these are correct.

Answer: a Difficulty: Hard Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

37) What was the initial explanation for the sensitivity of cancer cells to radiation therapy and chemotherapy as compared to normal cells? a) Cancer cells are sensitive to radiation and chemotherapy because they divide more rapidly. b) Cancer cells are sensitive to radiation and chemotherapy because once they sustain genetic damage, they continue through the cell cycle while repair is incomplete and that triggers metastasis. c) Cancer cells are sensitive to radiation and chemotherapy because they divide more slowly. d) Cancer cells are sensitive to radiation and chemotherapy because they will not undergo apoptosis.

Answer: a Difficulty: Easy

Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

38) What observation suggested that the elevated sensitivity of cancer cells to radiation therapy and chemotherapy was NOT due to their more rapid division? a) Cells that divide more quickly reproduce more effectively. b) Some cancer cells were observed to divide more slowly than their normal counterparts, yet they are still more sensitive to drugs and radiation than are normal cells. c) Cells that divide more quickly reproduced less effectively. d) Some cancer cells divide more quickly than their normal counterparts, yet they are still more sensitive to drugs and radiation than are normal cells. e) Normal cells dividing more slowly than tumor cells are more sensitive to drugs and radiation.

Answer: b Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

39) Under what circumstances are tumor cells likely to undergo apoptosis when they have sustained damage to DNA? a) if they have a functioning RP gene b) if they have a functioning TP53 gene c) if they have a non-functioning RP gene d) if they have a non-functioning TP53 gene e) if they have a non-functioning BAX gene Answer: b Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

40) _____________ is an inherited disease in which individuals develop many (hundreds or thousands) of premalignant polyps from epithelial cells lining the colon wall.

a) Familial adenomatous polyposis coli b) Familial hypercholesterolemia c) Inherited adenomitis d) Familial polypsoidemia e) Inherited polypoma intestines Answer: a Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

41) Patients suffering from familial adenomatous polyposis coli have typically been found to have a small _________ on chromosome 5, which is the site of the _________. a) deletion, RP tumor-suppressor gene b) deletion, APC oncogene c) duplication, APC tumor-suppressor gene d) deletion, APC tumor-suppressor gene e) duplication, RP tumor-suppressor gene Answer: d Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

42) A well-known cell-survival pathway involves a kinase called _______ that is activated by the _______, leading to a larger chance that the cell will survive a stimulus that would normally lead to its destruction. a) PKB, phosphoinositide PIP3 b) PKB, phosphoinositide PIP2 c) PRB, phosphoinositide PIP3 d) PKA, phosphoinositide PIP2 Answer: a Difficulty: Easy

Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

43) Whether a cell lives or dies after a particular genetic or epigenetic event depends to a large degree on ________ between ________ and _________ signals. a) the differences, mitotic, cytokinetic b) the balance, mitotic, apoptotic c) the balance, proapoptotic, antiapoptotic d) the differences, apoptotic, cytokinetic e) the differences, mitotic, apoptotic Answer: c Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

44) How does lipid phosphatase PTEN affect the balance between proapoptotic and antiapoptotic signals? a) PTEN removes the phosphate group from the 3-position of PIP3 converting it to PI(4,5)P2, which cannot activate PKB (AKT) and thus throws the balance in an antiapoptotic direction. b) PTEN removes the phosphate group from the 3-position of PIP3 converting it to PI(4,5)P2, which cannot activate PKB (AKT) and thus throws the balance in a proapoptotic direction. c) PTEN cuts a phosphate group off of PKB, which throws the balance in a proapoptotic direction. d) PTEN cuts a phosphate group off of PKB, which throws the balance in an antiapoptotic direction. e) PTEN adds a phosphate group to PKB, which throws the balance in a proapoptotic direction.

Answer: b Difficulty: Hard Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

45) What is the oncogene that is most often mutated in human tumors and what does it encode? a) the RAS gene, a GTP-binding protein that serves as an on-off switch for a key cell signaling pathway that controls cell proliferation b) the RAS gene, a DNA polymerase that replicates DNA for dividing cells c) the MYC gene, an RNA polymerase that transcribes mRNA encoding proteins needed for cell division d) the RB gene, a GTP-binding protein that serves as an on-off switch for a key cell signaling pathway that controls cell proliferation e) the MYC gene, a protein kinase that enhances cell differentiation Answer: a Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

46) The sis oncogene of the simian sarcoma virus was derived from what normal cellular gene? a) the Ras gene b) the gene for platelet-derived growth factor (PDGF) c) the gene for the insulin receptor d) the gene for the glucagon receptor e) the gene for epidermal growth factor Answer: b Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

47) The avian erythroblastosis virus contains an oncogene called erbB that encodes ___________. a) an altered EGF receptor that is missing part of the extracellular domain that binds to the growth factor b) an altered insulin receptor that binds insulin with lower affinity c) an altered transcription factor that turns on hemoglobin synthesis d) an elongated auxiliary protein of the cytoskeleton e) an underexpressed nuclear protein

Answer: a Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

48) How does the behavior of the altered erbB –encoded receptor that is the product of the avian erythroblastosis virus differ from the wild type form of the receptor? a) The altered receptor behaves in the same way as the wild-type receptor. b) The altered receptor constitutively stimulates cell growth in the presence and absence of the growth factor. c) The altered receptor stimulates cell growth in the presence of the growth factor, but not in its absence. d) The altered receptor constitutively represses growth and cell proliferation in the presence and absence of the growth factor. e) The altered receptor stimulates cell growth in the absence of the growth factor, but not in its presence.

Answer: b Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

49) What effect does the altered erbB –encoded receptor that is the product of the avian erythroblastosis virus have on the cells infected with the virus? a) The infected cells stop growing. b) The infected cells proliferate in an uncontrolled manner. c) The infected cells undergo apoptosis. d) The infected cells hyperdifferentiate.

Answer: b Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

50) What commonly happens to the number of EGF receptors in the plasma membranes of malignant cells as compared to normal cells? a) Malignant cells usually have the same number of receptors in their plasma membranes as normal cells. b) Malignant cells usually have a much larger number of plasma membrane receptors than normal cells. c) Malignant cells usually have a much smaller number of plasma membrane receptors than normal cells. d) Malignant cells usually have no plasma membrane receptors, while normal cells have them.

Answer: b Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

51) Raf is a ________ protein kinase at the top of the _______. a) tyrosine, MAP kinase cascade b) serine/threonine, MAP kinase cascade c) tyrosine, glucagon cascade d) serine/threonine, glucagon cascade e) serine/threonine, apoptosis cascade Answer: b Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

52) If Raf is mutated so that it is "on" constitutively, what is the effect on the cell? a) The cell stops dividing. b) The cell differentiates. c) The cell dedifferentiates. d) The cell loses growth control.

e) The cell increases in volume permanently.

Answer: d Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

53) The first oncogene discovered was _____, which codes for a _______. a) MYC, tyrosine protein kinase b) SRC, tyrosine protein kinase c) SRC, serine/threonine protein kinase d) MYC, serine/threonine protein kinase e) SRC, intermediary metabolism regulatory protein Answer: b Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

54) You culture cells and selectively block MYC gene expression. What is the effect on the cells? a) Cell progression through the cycle continues unabated. b) Cell progression through G1 is blocked. c) The cells arrest in the middle of mitosis. d) The cells arrest in the middle of meiosis. e) The cells arrest in the middle of S phase.

Answer: b Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

55) What virus seems to be related to the development of Burkitt's lymphoma in African patients, while it is associated only with minor infections, like mononucleosis, in the Western world? a) avian erythroblastosis virus b) simian sarcoma virus c) rhinovirus d) Epstein-Barr virus e) parvovirus Answer: d Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

56) The BCL-2 oncogene is most closely linked to _________; it encodes a membrane-bound protein that____________. a) apoptosis, normally acts to activate apoptosis b) apoptosis, normally acts to inhibit apoptosis c) uncontrolled proliferation, normally acts to inhibit apoptosis d) uncontrolled proliferation, normally acts to activate apoptosis e) apoptosis, binds to the insulin receptor tyrosine kinase Answer: b Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

57) How are drug companies trying to combat the ability of the BCL-2 gene to lower the effectiveness of chemotherapy? a) They are trying to develop drugs that stabilize cancer cells. b) They are trying to develop drugs that make cancer cells more likely to undergo apoptosis. c) They are trying to develop drugs that cause cancer cells to revert to normal embryonic cells. d) They are trying to develop drugs that cause cancer cells to dedifferentiate. e) They are trying to develop drugs that cause cancer cells to differentiate.

Answer: b Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

58) If any of the proteins involved in mismatch repair are damaged, the mutation rate and cancer risk will rise; this is called the ___________. a) stability phenotype b) mutator phenotype c) mutator genotype d) alteration phenotype e) alteration genotype Answer: b Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

59) What is the name for tiny regulatory RNAs that negatively regulate the expression of target mRNAs? a) tRNAs b) microRNAs c) mtRNAs d) macroRNAs e) rRNAs Answer: b Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

60) Because they act to _______ tumorigenesis, the miR-15a and miR-16 miRNAs can be thought of as _________. a) enhance, tumor suppressors b) inhibit, oncogenes c) enhance, oncogenes d) inhibit, tumor suppressors Answer: d Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

61) Which of the following enzymes is known to be expressed at a high level in the cancer cells of patients suffering from acute myeloid leukemia and at low levels in the cancer cells of patients suffering from acute lymphoblastic leukemia? a) cholesterase b) catalase c) adenylyl cyclase d) phosphodiesterase e) protein kinase A Answer: b Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

62) After the DNAs attached to the glass slide of a microarray are exposed to a probe, how are they usually visualized? a) The cDNA probes are fluorescently labeled. b) The mRNA probes are fluorescently labeled. c) The cDNA probes are radioactively labeled. d) The cDNA probes are labeled with ferritin. e) The mRNA probes are labeled with ferritin.

Answer: a

Difficulty: Easy Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

63) The genes involved in tumorigenesis constitute a specific subset of the genome whose products are involved in which of the following activities? a) progression of a cell through the cell cycle b) adhesion of a cell to its neighbors c) apoptosis d) repair of DNA damage e) all of these are correct Answer: e Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

64) Mutant forms of which of the following genes have been associated with melanomas and colorectal cancers, respectively? a) APC and ZUNI b) BRAF and CCMD c) BRAF and APC d) CCMD and APC e) ZUNI and BRAF Answer: c Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

65) With respect to cancer genetics and the cancer genome, what are passenger genes?

a) genes that are subject to mutation but have no effect on the phenotype of a cancer cell b) genes that are not subject to mutation and have no effect on the phenotype of a cancer cell c) genes that are subject to mutation but have a large effect on the phenotype of a cancer cell d) genes that are subject to mutation but have no effect on the genotype of a cancer cell e) genes that are subject to mutation but have no effect on the phenotype of an egg cell Answer: a Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

66) What was the first radiation source that was discovered? a) X-rays b) radium c) Gamma rays d) ultra-violet light e) uranium Answer: b Difficulty: Easy Learning Objective: LO 16.4 Explain the different ways in which radiation is used to treat cancer.

Section Reference: Section 16.4 Engineering Linkage: Therapeutic Radiation

67) Which statement about therapeutic radiation is NOT correct? a) radiation therapy can be used to reduce symptoms (palliatively) b) radiation never cures cancer unless it is used in conjunction with chemotherapy c) external beam radiation therapy produces high energy electron beams or X-rays d) internal radiation therapy places a small amount of radioactive isotope at the tumor site Answer: b Difficulty: Medium Learning Objective: LO 16.4 Explain the different ways in which radiation is used to treat cancer.

Section Reference: Section 16.4 Engineering Linkage: Therapeutic Radiation

68) How is it believed that therapeutic radiation acts to kill tumor cells? a) Double stranded breaks in DNA are introduced, disrupting chromosomal integrity. b) Free radical damage is increased within cells which damages cytosolic and membrane components. c) Free radical damage is increased within cells which damages DNA. d) All are correct choices.

Answer: d Difficulty: Medium Learning Objective: LO 16.4 Explain the different ways in which radiation is used to treat cancer.

Section Reference: Section 16.4 Engineering Linkage: Therapeutic Radiation

69) Vinca alkaloids are responsible for all of the following EXCEPT: a) destruction of white blood cells b) microtubule binding c) intermediate filament binding d) arresting cell division e) causing metaphase arrest Answer: c Difficulty: Medium Learning Objective: LO 16.5 Identify the origins of the plant-based chemotherapies used to treat cancer.Section Reference: Section 16.5 Green Cells: Plant-based Chemotherapies

70) Which of these anti-cancer drugs acts to inhibit topoisomerase I? a) vinblastine b) taxol c) camptothecin d) podophyllotoxin e) etoposide Answer: c Difficulty: Medium

Learning Objective: LO 16.5 Identify the origins of the plant-based chemotherapies used to treat cancer.Section Reference: Section 16.5 Green Cells: Plant-based Chemotherapies

71) Twenty-first century drug research using computational methods hopes to identify new medications from which of the following sources? a) plants b) fungi c) bacteria d) all are correct choices Answer: d Difficulty: Easy Learning Objective: LO 16.5 Identify the origins of the plant-based chemotherapies used to treat cancer.Section Reference: Section 16.5 Green Cells: Plant-based Chemotherapies

72) What is a “humanized” monoclonal antibody, as used in passive immunotherapy? a) An antibody that is derived from mouse lymphocytes and used in human cancer therapy b) A human antibody that is produced by one cancer patient and administered to another c) A mouse-produced engineered antibody with an antigen recognition surface of mouse origin d) An antibody that is introduced for expression in humans by human researchers e) An antibody against a tumor antigen that is produced by healthy people Answer: c Difficulty: Medium Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

73) How might blocking angiogenesis have a negative impact as a cancer treatment? (Select all correct choices) a) by creating a higher oxygen tension in the tissue b) by concentrating tumor cells at a particular location in the body c) by creating a more O2-deficient environment for the tumor cells d) by driving tumor cells to seek out other sites in the body

Answer: c, d Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer. Section Reference: Section 16.6 Strategies for Combating Cancer

74) For what disease has the bispecific monoclonal antibody Blincyto approved for treatment? a) acute lymphocytic leukemia b) chronic lymphocytic leukemia c) ALS (Lou Gehrig's disease) d) multiple sclerosis e) glioblastoma Answer: a Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

75) The cancer vaccine Provenge utilizes which type of cells from the patient? a) erythrocytes b) fibroblasts c) Schwann cells d) white blood cells e) prostate cells Answer: d Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

76) What is a xenograft?

a) transplanting cells in the presence of xenon b) a transplant of cells from one organism to an organism of a different species c) mixing cells from two different species in a culture dish d) a transplant that does not have a good histocompatibility antigen match e) a skin graft from one organism to another within the same species Answer: b Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

77) Which of the following is NOT a mechanism of action for a small-molecule targeted therapy? a) stimulation of tyrosine kinase b) inhibition of MAP kinase cascade c) blocking cell-survival pathways d) induction of apoptosis e) inhibition of estrogen synthesis Answer: e Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

78) Which of the following is a biomarker that could reveal the presence of cancer through a blood test or screening? a) mutant DNA b) abnormal carbohydrates c) distinctive metabolites d) presence of cancer cells e) all of these are correct Answer: e Difficulty: Medium

Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

79) Which of the following is presently being used as a screening procedure for cancer? a) mammography for detecting breast cancer b) Pap smears for detecting cervical cancer c) PSA determinations for detecting prostate cancer d) colonoscopy for detecting colorectal cancer e) all of these are used to screen for cancer Answer: e Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

80) __________ is an approach that tries to get the immune system more involved in the fight against cancer. a) Active immunotherapy b) Gene therapy c) Inhibition of cancer-promoting proteins d) Inhibition of angiogenesis e) Passive immunotherapy Answer: a Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

81) William Coley, a New York physician in the late 1800s, studied spontaneous remissions of terminal cancer cases. He read that one man, who had an inoperable neck tumor, had gone into remission after what event? a) after a cold

b) after changing his diet drastically c) after a streptococcal infection beneath his skin d) after a rigorous exercise regimen e) after taking multiple vitamins Answer: c Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

82) After his initial discoveries and for the rest of his life, Coley tried to develop a ______ extract that when injected under the skin would stimulate a patient's immune system to destroy their malignancy. His approach called ________ worked against some uncommon__________. a) bacterial, Coley's toxin, soft-tissue carcinomas b) bacterial, Coley's solution, soft-tissue sarcomas c) viral, Coley's toxin, soft-tissue sarcomas d) bacterial, Coley's toxin, soft-tissue sarcomas e) human cytoplasmic, Coley's cure, soft-tissue hepatomas Answer: d Difficulty: Medium Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

83) ________ is a humanized antibody directed against a cell surface receptor called _____ that binds a growth factor responsible for stimulating the proliferation of breast cancer cells. a) Ascriptin, ASC3 b) Herceptin, HER2 c) Apcolin, APC2 d) Herceptin, Raf e) Rafinolin, Raf Answer: b Difficulty: Easy

Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

84) About 25% of breast cancers are composed of cells that overexpress the HER2 gene. What property does the overexpression of this gene confer upon the tumor cells? a) The tumor cells are more responsive to Herceptin stimulation in the body. b) The tumor cells are less responsive to Herceptin stimulation. c) The tumor cells are more likely to undergo apoptosis. d) These cells are especially sensitive to growth factor stimulation. e) These cells are especially resistant to growth factor stimulation.

Answer: d Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

85) Which molecule do Rituxan and Zevalin antibodies attack? a) collagen b) CD20 c) myeloid protein d) actin e) EGF receptor Answer: b Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

86) If patients with advanced chronic myelogenous leukemia were initially treated with Gleevec, they eventually develop resistance to the drug. What seems to cause the resistance? a) mutations in the BCR portion of the fusion gene b) mutations in the ABL portion of the fusion gene

c) ABL gene deletion d) ABL gene amplification e) BCR gene amplification Answer: b Difficulty: Medium Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

87) The development of chronic myelogenous leukemia tumor-resistance to Gleevec appears to be a common occurrence. What is presently thought to be the best drug regimen for treating chronic myelogenous leukemia? a) a cocktail of several different inhibitors that target different parts of the Abl protein b) a cocktail of several different inhibitors that target the same parts of the Abl protein c) a cocktail of several different inhibitors that target common domains of different proteins d) a cocktail of several different inhibitors that target the different parts of different proteins Answer: a Difficulty: Medium Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

88) __________ is a term to describe new blood vessel formation. a) Vesselogeny b) Angiogenesis c) Formational vessels d) Angiotension e) Venogenesis Answer: b Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

89) Judah Folkmann suggested that solid tumors might be __________. a) destroyed by enhancing their ability to form new blood vessels b) dissipated by enhancing the ability of cancer cells to separate from each other c) destroyed by inhibiting their ability to form new blood vessels d) enlarged by breaking down neighboring tissues e) desiccated by osmotic action Answer: c Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

90) Why is the use of angiogenesis inhibitors less likely to stimulate the development of resistance when used to treat cancers? a) Angiogenesis inhibitors target normal, genetically stable, endothelial cells, which continue to respond to the presence of these agents. b) Angiogenesis inhibitors have low affinity for blood vessels. c) Angiogenesis inhibitors are unstable and do not survive long enough to induce resistance. d) Angiogenesis inhibitors are stable and survive too long to induce resistance.

Answer: a Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

91) Which type of new screening test will be able to identify cancers based on the relative levels of various proteins in the blood? a) genomics b) Pap smear c) colonoscopy d) proteomics e) epinomics

Answer: d Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

92) Which type of new screening test will be able to identify cancers based on the presence of specific genes associated with various types of cancer? a) genomics b) Pap smear c) colonoscopy d) proteomics e) epinomics Answer: a Difficulty: Easy Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

93) Which of the following statements does NOT support the concept of cancer stem cells? a) Drugs such as Gleevec that reduce tumor mass may not eliminate all cells in the tumor. b) Tumor cells are not homogeneous and can express different cell-surface markers. c) Treatment with drugs that stimulate stem cell differentiation improves the efficacy of small-molecule targeted therapies. d) A key feature of cancer is that cells of a primary tumor are capable of unlimited proliferation. e) Only some cells from a tumor are able to initiate the formation of a new tumor following injection into an immunodeficient mouse.

Answer: d Difficulty: Hard Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

94) What is the proposed mechanism of action for the cancer stem cell-targeting drug tarextumab? a) stimulation designed to turn cancer stem cells into tumor cells b) stimulation designed to turn tumor cells into cancer stem cells c) stimulation of a stem-cell specific immune response d) inhibition of tyrosine kinase signaling e) stimulation of MAP kinase signaling Answer: a Difficulty: Medium Learning Objective: LO 16.6 Outline current and proposed strategies for treating and preventing cancer.

Section Reference: Section 16.6 Strategies for Combating Cancer

Question Type: Multiple Select

95) What types of genetic alterations might make humans more likely to develop a particular type of cancer? (Select all correct choices) a) those that a parent obtains from his/her child b) germline mutations c) those that occur in eggs after menopause d) somatic mutations Answer: b, d Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

Question Type: Multiple Select

96) Studies of identical twins suggest that ________. (Select all correct choices) a) the genes we inherit have a significant influence on our risks of developing cancer

b) the greatest impact on cancer development comes from genes altered during our lifetime c) genes play a very small role in cancer development d) genes play no role in cancer development Answer: a, b Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

Question Type: Multiple Select

97) What happens to a cell that is carrying damaged DNA if both of its TP53 alleles become inactivated? (Select all correct choices) a) It lacks the genetic integrity required for controlled growth. b) It lacks the genetic integrity required for uncontrolled growth. c) It fails to be destroyed. d) It is destroyed through apoptosis.

Answer: a, c Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

Question Type: Multiple Select

98) Which of the following are actions of p53? (Select all correct choices) a) The p53 protein can bind to several members of the Bcl-2 family proteins in a manner that stimulates apoptosis. b) The p53 protein can bind to Bax proteins at the outer mitochondrial membrane, directly triggering membrane permeabilization and release of apoptotic factors. c) The p53 protein can bind to several members of the Bcl-2 family proteins in a manner that stimulates meiosis.

d) The p53 protein can bind to DNA and proofread it for errors.

Answer: a, b Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

Question Type: Multiple Select

99) Lacking any functional TP53 gene __________. (Select all correct choices) a) causes a cell carrying damaged DNA to be destroyed b) causes a cell carrying damaged DNA to fail to be destroyed c) will allow genetically unstable cells to continue to divide d) will stop genetically unstable cells from dividing Answer: b, c Difficulty: Medium Learning Objective: LO 16.3 Compare the roles of tumor-suppressor genes and oncogenes in tumor cell formation.

Section Reference: Section 16.3 Cancer: A Genetic Disorder

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 17

Question Type: Multiple Choice

1) All types of immune responses are based upon ___________. a) body mass b) the pH and salt concentration in blood c) the presence of viruses d) the body's ability to distinguish between materials that are supposed to be there (self) and those that are foreign (nonself) Answer: d Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

2) _________ immune responses are mounted by the body immediately without requiring previous contact with the microbe; they are the initial internal line of defense and are characterized by a lack of specificity. a) Innate b) Acquired c) Adaptive d) Intuitive e) Inductive Answer: a Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

3) Cells of the innate immune system have receptors on their surfaces that help them to recognize ____________.

a) the DNA of invading pathogens b) the RNA of invading pathogens c) conserved macromolecules that are characteristic of viruses and bacteria d) conserved chemical groupings that are characteristic of other white blood cells e) the cell surfaces of viruses Answer: c Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

4) Receptors on the surfaces of phagocytic cells which recognize certain types of highly conserved molecules that play essential roles in viruses and bacteria are called _______. a) pattern recognition receptors b) PRRs c) toll-like receptors d) TLRs e) all of these are correct Answer: e Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

5) What causes inflammation at the site of an infection? a) certain cells and plasma proteins leaving the blood vessels and entering the affected tissues b) certain cells and plasma proteins entering the blood vessels and leaving the affected tissues c) release of a chemical that has the purpose of reddening the tissues) fluid leaving the infected region by osmosis Answer: a Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

6) What causes phagocytic white blood cells like neutrophils and macrophages to migrate toward the site of infection? a) high pH b) high glucose concentration c) low pH d) chemoattractants released at the site e) calcium ions released into the region Answer: d Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

7) ________ are a variety of antimicrobial peptides secreted by epithelial cells and lymphocytes; these peptides are able to bind to viruses, bacteria or fungi and target them for destruction. a) Immunoglobulins b) Gamma globulins c) Defensins d) Antibodies Answer: c Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

8) Blood contains a group of soluble proteins, which bind extracellular pathogens and destroy them. In one case, an assembly of these activated soluble proteins perforates the bacterial cell membrane, causing lysis and death of the cells. What is this group of soluble proteins called? a) composite proteins b) complement proteins c) complimentary proteins d) complete proteins Answer: b Difficulty: Easy

Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

9) How does the immune system initiate responses against intracellular pathogens like viruses, when they are hidden inside cells? a) The immune system attacks intracellular pathogens primarily by killing cells that have already been infected. b) The immune system only attacks these intracellular pathogens when they are found in the extracellular space. c) Cells of the immune system secrete proteins that penetrate infected cells and attack the pathogens intracellularly. d) All of these are correct.

Answer: a Difficulty: Medium Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

10) Natural killer cells cause the death of virus-infected cells by inducing them to undergo _________. a) rapid growth b) apoptosis c) perforation of their membranes d) solubilization of their membranes e) dehydration Answer: b Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

11) Which of the following is NOT a protein produced by virus-infected cells and secreted into the extracellular space where they bind to the surface of noninfected cells rendering them resistant to subsequent infection? a) type 1 interferons

b) immunoglobulins c) interferon α d) interferon β Answer: b Difficulty: Medium Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

12) What is the name for nucleated white blood cells that circulate between the blood and lymphoid organs? a) neutrophils b) basophils c) leukophils d) lymphocytes e) adipocytes Answer: d Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

13) What is a leukocyte? a) a red blood cell b) a platelet c) a white blood cell d) a complement protein e) a hepatocyte Answer: c Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

14) Which type of immunity is carried out by antibodies and initiated by B lymphocyte stimulation? a) humorous immunity b) cell-mediated immunity c) lymphocytic immunity d) humoral immunity e) surface-mediated immunity Answer: d Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

15) Which of the following are globular, blood-borne proteins of the immunoglobulin superfamily (IgSF)? a) antigens b) albumins c) heparins d) antibodies e) thrombospondins Answer: d Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

16) Which cells are responsible for synthesizing and secreting antibodies? a) T cells or T lymphocytes b) antigen cells c) B cells or B lymphocytes d) platelets e) erythrocytes Answer: c Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

17) Which cells are responsible for cell-mediated immunity? a) T cells or T lymphocytes b) antigen cells c) B cells or B lymphocytes d) platelets e) erythrocytes Answer: a Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

18) Why is cell-mediated immunity (in addition to humoral immunity) needed to defend the body against invading pathogens? a) Humoral immunity is ineffective against antibodies. b) Antibodies are not effective against pathogens that are present inside cells. c) Antibodies are not effective against pathogens that are present outside cells. d) If used too often, antibodies can attack red blood cells. e) Antibodies are typically ineffective against bacteria, while they work well against viruses.

Answer: b Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

19) What is the name of the type of cell that serves as the precursor cell for both B cells and T cells? a) the hematopelagic stem cell b) the fertilized egg c) the hematopoietic stem cell d) the pluripotent hepatologic stem cell e) the sperm cell

Answer: c Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

20) Which cells of the immune system differentiate in the thymus gland? a) T cells or T lymphocytes b) antigen cells c) B cells or B lymphocytes d) platelets e) macrophages Answer: a Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

21) What immune system organ is located in the chest, is responsible for the differentiation of T cells, and reaches its peak size during childhood? a) the thyroid gland b) the adrenal gland c) the thymus gland d) the lymph nodes e) the liver Answer: c Difficulty: Easy Learning Objective: LO 17.1 Describe how innate and adaptive immunity combat infection.

Section Reference: Section 17.1 An Overview of the Immune Response

22) Which immune system component is found in plants but NOT vertebrates? a) pattern recognition receptors b) PAMP receptors c) PRRs

d) NLRs Answer: d Difficulty: Easy Learning Objective: LO 17.2 Distinguish the plant and animal immune systems.

Section Reference: Section 17.2 Green Cells: The Plant Immune System

23) Sensing of pathogen effector proteins by plant cells can lead to all of the following defensive responses EXCEPT: a) regulating the levels of plant immune defenses through NLR activities b) production of intracellular proteins called nucleotide binding domain leucine-rich repeat containing receptors (NLRs) c) production of oxygen radicals d) production of NK cells Answer: d Difficulty: Medium Learning Objective: LO 17.2 Distinguish the plant and animal immune systems.

Section Reference: Section 17.2 Green Cells: The Plant Immune System

24) PAMP-triggered immunity in plants can activate over 1,000 genes in Arabidopsis via _________________ -mediated stimulation. a) calcium ion b) protein kinase c) signal transduction d) single transcription factor Answer: c Difficulty: Easy Learning Objective: LO 17.2 Distinguish the plant and animal immune systems.

Section Reference: Section 17.2 Green Cells: The Plant Immune System

25) The foreign molecules that stimulate the adaptive immune system to make antibodies are called ________.

a) integrins b) antigens c) antibodies d) thrombins e) albumins Answer: b Difficulty: Easy Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

26) Which of the following models for the induction of antibodies was proposed initially by Niels Jerne? a) The body makes small amounts of randomly structured antibodies in the absence of any antigen; exposure to an antigen leads to the production of the corresponding antibody. b) Antibodies are ingested from food and stored in the body until exposed to corresponding antigens. c) Antibodies are molded over the surface of antigens. d) Antibodies are reverse engineered from the DNA of bacterial pathogens Answer: a Difficulty: Easy Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

27) What is the source of activated B cell populations? a) T cells b) a population of undifferentiated and indistinguishable progenitor cells c) a population of differentiated and specific progenitor cells d) a population of undifferentiated and indistinguishable descendent cells e) platelets Answer: b Difficulty: Easy

Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

28) What events lead to a differentiating B cell becoming committed to producing only one species of antibody molecule? a) protein rearrangements in the genome b) RNA rearrangements in the genome c) DNA rearrangements in the genome d) DNA rearrangements in the mitochondrion e) spontaneous production of proteins in the Golgi complex Answer: c Difficulty: Medium Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

29) What allows so many different antibodies to be made by the immune system? a) because mistakes are made during DNA replication b) because mistakes are made during transcription c) because mistakes are made during reverse transcription d) because thousands of different DNA rearrangements are possible e) because thousands of different mRNA alterations are possible Answer: d Difficulty: Medium Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

30) When does the full repertoire of antibody-producing cells (all such cells that a person will ever have) appear in the lymphoid tissue? a) in the fertilized egg b) before stimulation by an antigen

c) before stimulation by an antibody d) after stimulation by all of the possible antibodies e) after stimulation by any of the possible antigens Answer: b Difficulty: Medium Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

31) What is usually required for B cell activation by an antigen? a) other B cell interactions b) T cell activity c) platelets d) megakaryocytes e) erythrocytes Answer: b Difficulty: Easy Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

32) Which of the antigens below are typically able to activate B cells without the involvement of T cells? a) very large bacterial lipids b) very large viral lipids c) bacterial cell wall polysaccharides d) bacterial cell wall polypeptides e) bacterial DNA Answer: c Difficulty: Easy Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

33) When an antigen binds to the antibody in the membrane of a B cell, the B cell proliferates and forms a population of B lymphocytes that all make the same antibody. The population of B lymphocytes thus formed is called ________. a) a group b) a clone c) an identicon d) a proliferate e) a codon Answer: b Difficulty: Easy Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

34) Some activated B cells differentiate into short-lived cells that secrete large amounts of antibodies. Such cells are called __________. a) memory cells b) activation cells c) plasma cells d) secretion cells e) antibody-producing cells Answer: c Difficulty: Easy Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

35) What cellular structure is found to be greatly expanded in plasma cells, but not in their precursor cells? a) nuclei b) mitochondria c) chloroplasts d) rough endoplasmic reticulum

e) lysosomes Answer: d Difficulty: Easy Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

36) Some activated B cells remain in lymphoid tissue and respond rapidly at a later date if the antigen reappears in the body. Such cells are called __________. a) memory B cells b) activation B cells c) plasma cells d) secretion cells e) antibody-producing cells Answer: a Difficulty: Easy Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

37) What happens to plasma cells after the removal of the original antigenic stimulus? a) They die off. b) They may, in some cases, persist for the person's lifetime. c) They revert to precursor cells. d) They proliferate even more. e) They dedifferentiate.

Answer: a Difficulty: Easy Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

38) Genes encoding antibodies are generated by a process in which DNA segments are _______ combined. a) randomly b) purposely c) slowly d) rapidly e) incompletely Answer: a Difficulty: Easy Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

39) Who realized that a cowpox infection at an early age protected people against deadly smallpox infections? a) Gregor Mendel b) Edward Jenner c) Claude Bernard d) Louis Pasteur Answer: b Difficulty: Easy Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

40) _________ are capable of stimulating immunity but are genetically modified so that they are unable to cause disease. a) Autistic pathogens b) Paralyzed pathogens c) Attenuated pathogens d) Dystrophied pathogens e) Disadvantaged pathogens Answer: c Difficulty: Easy

Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

41) The modified, harmless version of the tetanus toxin that is used to immunize infants is called a _______. a) toxin b) poison c) toxoid d) toxico e) toxon Answer: c Difficulty: Easy Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

42) Why are the second and subsequent responses to antigen exposure faster than the initial response? a) The antibodies of the secondary response are more efficient. b) The antibodies of the secondary response are less efficient. c) After the initial exposure, memory cells are present; they respond more quickly upon a second exposure to the antigen. d) After the initial exposure, the memory cells respond more slowly, as the pool of available cells has been diminished. e) Pathogens are generally weaker with the second exposure.

Answer: c Difficulty: Medium Learning Objective: LO 17.3 Explain the clonal selection theory and what it means for a B cell to become committed to antibody formation.

Section Reference: Section 17.3 The Clonal Selection Theory as It Applies to B Cells

43) What is found on the surface of T cells?

a) T cell receptors that allow a specific interaction with a particular antigen b) B cells receptors that allow a specific interaction with a particular antigen c) T cell antigens that allow a specific interaction with a particular antigen d) B cell antigens that allow a specific interaction with a particular antigen e) platelet receptors that allow a specific interaction with a particular antigen Answer: a Difficulty: Easy Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

44) How many types of T-cell receptors does each T cell have? a) one b) two c) up to ten d) an infinite number e) four Answer: a Difficulty: Easy Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

45) B cells are activated by ________ and T cells are activated by ______. a) soluble, intact antigens; antigen fragments displayed on the surfaces of other cells b) soluble, intact antigens; soluble, intact antigens c) antigen fragments displayed on the surfaces of other cells; soluble, intact antigens d) antigen fragments displayed on the surfaces of other cells; antigen fragments displayed on the surfaces of other cells e) insoluble, intact antigens; antigen fragments displayed on the surfaces of other cells Answer: a Difficulty: Medium Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

46) How is the material ingested by dendritic cells fragmented? a) Fragmentation is random. b) Enzymes in the cytoplasm of the dendritic cells fragment the antigens of the ingested material. c) Enzymes in the nucleus of the dendritic cells fragment the antigens of the ingested material. d) The lower pH of the cytoplasm fragments the antigenic foreign material. e) The higher pH of the cytoplasm fragments the antigenic foreign material.

Answer: b Difficulty: Medium Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

47) Where do dendritic cells go once they have processed antigens and what do they do when they get there? a) They go to the lymph nodes, where they undergo apoptosis. b) They go to the liver, where they undergo apoptosis. c) They go to the lymph nodes, where they differentiate into mature antigen-presenting cells. d) They go to the liver, where they differentiate into mature antigen-presenting cells. e) They go to the liver, where they proliferate.

Answer: c Difficulty: Medium Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

48) What is a physical/clinical sign that a person's immune system is involved in the proliferation of T cells in response to an infection? a) The skin is reddened. b) The lymph nodes in the region of the infection become enlarged. c) The skin is bruised in the infected region. d) The lymph nodes shrink because they are secreting so much material.

e) The temperature of the infected region decreases.

Answer: b Difficulty: Easy Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

49) What subfamily of small cytokines acts primarily as chemoattractants that stimulate the migration of lymphocytes into inflamed tissue? a) minicytokines b) interleukins c) chemokines d) interferons e) tumor necrosis factors Answer: c Difficulty: Easy Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

50) Which class of T cells is composed of primarily inhibitory cells that suppress the proliferation and activities of other types of immune cells that are capable of mounting an autoimmune response? a) helper T lymphocytes b) inhibitory T lymphocytes c) cytotoxic T lymphocytes d) regulatory T lymphocytes e) deactivating T lymphocytes Answer: d Difficulty: Easy Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

51) _________ screen body cells for aged, infected or malignant cells and then attack them. a) Helper T lymphocytes b) Inhibitory T lymphocytes c) Cytotoxic T lymphocytes d) Regulatory T lymphocytes e) B lymphocytes Answer: c Difficulty: Easy Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

52) Which of the following are proteolytic enzymes that enter perforin channels and activate caspases, which in turn initiate the apoptotic response? a) granzymes b) proteolysinase c) proteases d) lysozymes e) protein kinase B Answer: a Difficulty: Easy Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

53) Which cells of the immune system produce IFN-ɤ and protect the body against intracellular pathogens by activating macrophages to kill pathogens they might harbor? a) TH1 cells b) TH2 cells c) cytotoxic T lymphocytes d) B cells e) regulatory T lymphocytes

Answer: a Difficulty: Medium Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

54) Which cells of the immune system produce IL-4, which mobilizes mast cells, basophils and eosinophils to protect against extracellular pathogens, especially parasitic worms? a) TH1 cells b) TH2 cells c) cytotoxic T lymphocytes d) TH17 cells e) regulatory T lymphocytes Answer: b Difficulty: Medium Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

55) Which cells of the immune system produce an interleukin, which is thought to stimulate epithelial cells to recruit phagocytes and thereby prevent the entry of extracellular bacteria and fungi into the body? a) TH1 cells b) TH2 cells c) cytotoxic T lymphocytes d) TH17 cells e) regulatory T lymphocytes Answer: d Difficulty: Medium Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

56) Which cells are the primary target of HIV, the virus that causes AIDS? a) cytotoxic T lymphocytes b) helper T lymphocytes c) B lymphocytes d) macrophages e) regulatory T lymphocytes Answer: b Difficulty: Medium Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

57) Which cells are characterized by their possession of CD4 and CD25 surface markers? a) TH1 cells b) TH2 cells c) cytotoxic T lymphocytes d) B cells e) regulatory T lymphocytes Answer: e Difficulty: Easy Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

58) What fatal disease is characterized by severe autoimmunity in newborn infants and is caused by a mutation in a gene that encodes a transcription factor required for the differentiation of TReg cells? a) IPEX b) IBEX c) multiple sclerosis d) sudden infant death syndrome e) Tay-Sachs disease Answer: a

Difficulty: Medium Learning Objective: LO 17.4 Describe the activation of the three types of T lymphocytes and the role of cytokines.

Section Reference: Section 17.4 T Lymphocytes: Activation and Mechanism of Action

59) Which bonds are largely responsible for holding the heavy and light chains of an immunoglobulin together? a) H bonds b) ionic bonds c) van der Waals forces d) disulfide bonds e) hydrophobic interactions Answer: d Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

60) Which antibodies are the first to be secreted by B cells after antigen stimulation, appear in the blood after a lag of a few days, and have a relatively short half-life? a) IgD b) IgA c) IgM d) IgK e) IgG Answer: c Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

61) Which antibodies are the predominant antibodies found in blood and lymph during a secondary response to most antigens? a) IgGs b) IgAs c) IgMs d) IgEs e) IgDs Answer: a Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

62) Which antibodies are the predominant antibodies in secretions of the respiratory, digestive and urogenital tracts? a) IgGs b) IgAs c) IgMs d) IgEs e) IgDs Answer: b Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

63) Which antibodies have no clearly understood function? a) IgGs b) IgAs c) IgMs d) IgEs e) IgDs

Answer: e Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

64) There are two types of IgG light chains. What are they? a) alpha (α) and beta (β) b) alpha (α) and omega (Ω) c) kappa (κ) and lambda (λ) d) delta (δ) and gamma (ɤ) e) kappa (κ) and delta (δ) Answer: c Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

65) What process is probably responsible for the origin of the three parts of the constant portion of the IgG heavy chain? a) inversion b) duplication c) deletion d) point mutation e) nonsense mutation Answer: b Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

66) The chains of an immunoglobulin molecule are divided into a light chain domain and a heavy chain domain; each domain is encoded by __________. a) two exons b) two introns c) its own exon d) its own intron e) an intron and an exon Answer: c Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

67) What determines the specificity of an antibody? a) the amino acids of the antigen-combining sites at the ends of each arm of the Y-shaped antibody b) the amino acids of the antigen-combining sites at the base of the Y-shaped antibody c) the nucleic acids of the antigen-combining sites at the base of the Y-shaped antibody d) the nucleic acids of the antigen-combining sites at the ends of each arm of the Y-shaped antibody e) the amino acids of the antigen-combining sites at the end of one arm of the Y-shaped antibody Answer: a Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

68) The variable portions of both heavy and light chains contain subregions that are especially variable from one antibody to another; these variable subregions account for the great diversity of antibody specificity. Such portions of both the light and heavy chains are called _________ regions. a) hypovariable b) hypervariable

c) hypoconstant d) hyperconstant e) extremovariable Answer: b Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

69) What kind of interactions hold the antigen and antibody together at the antigen-combining site of the antibody? a) covalent interactions b) noncovalent forces c) disulfide bonds d) ionic bonds Answer: b Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

70) While the hypervariable regions of the light and heavy chains determine an antibody's combining site specificity, the remaining portions of the variable regions perform the function of ____________. a) providing a scaffold that maintains the overall combining site structure b) providing a scaffold that maintains the overall antibody structure c) attaching to macrophages d) attaching to dendritic cells Answer: a Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

71) The heavy chains of which class of antibody bind and activate one of the complement system proteins, leading to the lysis of the bacterial cell to which the antibody molecules are bound? a) IgM b) IgG c) IgE d) IgD e) IgA Answer: a Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

72) Which of the following plays an important role in allergic reactions by binding to mast cell surfaces and what event does the binding stimulate? a) IgE heavy chains, the release of histamine b) IgE heavy chains, the release of allergan c) IgE light chains, the uptake of histamine d) IgE light chains, the release of allergan e) IgA heavy chains, the release of histamine Answer: a Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

73) The heavy chains of which class of antibody bind specifically to macrophage and neutrophil surface receptors, inducing these phagocytes to ingest the particle to which the antibodies are bound?

a) IgM b) IgG c) IgE d) IgD e) IgA Answer: b Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

74) Introduction of antibodies made against a particular invading organism into another organism by injection or some other similar method is called the provision of____________. a) active immunity b) primary immunity c) secondary immunity d) passive immunity e) tertiary immunity Answer: d Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

75) The ability of human maternal antibodies to get into the fetal circulation can lead to a life-threatening condition in which the fetal red blood cells are killed; this condition is known as ___________. a) lupus erythematosus b) erythroblastosis fetalis c) aplastic anemia d) sickle cell anemia e) erythemia

Answer: b Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

76) The DNA sequences involved in the formation of human Kappa (κ) light chains are located on chromosome ____. a) 22 b) 14 c) 2 d) X e) Y Answer: c Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

77) The nucleotides encoding the 13 amino acids at the C-terminal end of the Vκ region is called the ____. a) Q segment b) C segment c) J segment d) VJ segment e) M segment Answer: c Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

78) Nucleotide sequence analysis of the V genes indicate that they are ________ than required to encode the V region of the κ light chain. a) shorter b) longer c) the same length as d) more coiled e) less coiled Answer: a Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

79) A complete κ V gene is formed as a specific Vκ gene is joined to one of the Jκ segments with the intervening DNA excised; the process is catalyzed by a protein complex called ___________. a) V(D)J polymerase b) V(D)J recombinase c) V(D)J joinase d) V(D)J ligase e) ligandase Answer: b Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

80) What characteristic does gene rearrangement lend to immunoglobulin molecules? a) stability b) variability c) efficiency d) speed

e) fragility Answer: b Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

81) You are studying a weasel and find that its genome contains 7 Jκ and 55 Vκ genes.

Assuming that any V sequence can join with any J sequence, how many different kappa chains can this organism make? a) 62 b) 385 c) 350 d) 7 e) 55 Answer: b Difficulty: Hard Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

82) You are studying a weasel and find that its genome contains 7 Jκ and 55 Vκ genes. Other sources of variation (such as changes in the site at which a J sequence joins a V sequence and the ability of deoxynucleotidyl transferase to insert nucleotides at sites of strand breakage) have been found to introduce an additional ten-fold increase in variability. Assuming that any V sequence can join with any J sequence, how many different κ light chains can this organism make? a) 620 b) 385 c) 3850 d) 70 e) 550 Answer: c

Difficulty: Hard Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

83) Heavy chain variable regions consist of which of the following combinations of segments? a) V, D and J segments b) V and J segments c) D and J segments d) V, M and J segments e) V, D, M and J segments Answer: a Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

84) The human genome has been shown to code for 51 different functional VH segments, 25 different DH segments and 6 JH segments for the heavy chain variable regions of antibodies.

Assuming that any V segment can combine with any of the D and J segments, how many different heavy chains could be made? a) 7650 b) 765 c) 82 d) 820 e) 76,820 Answer: a Difficulty: Hard Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

85) In what way does the character of the antibodies made during a secondary response differ from those made during the primary response? a) They are bigger. b) They are smaller. c) The antibodies of the secondary response have a much greater affinity for their antigen. d) The antibodies of the secondary response have a much lower affinity for their antigen. e) They are more stable.

Answer: c Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

86) The rearranged DNA elements encoding the V regions of antibodies are estimated to have a mutation rate 105 times greater than that of other genetic loci in the same cell. This phenomenon is referred to as __________. a) somatic hypermutation b) somatic hypomutation c) somatic hyperattenuation d) enhanced mutability e) mutational hyperannuity Answer: a Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

87) _________ occurs when a specific antibody changes the heavy chain that the cell makes without changing the antigen-combining site of the antibodies synthesized. a) Class consistency b) Somatic hypermutation c) Class switching

d) Class hypermutation e) Somatic switching Answer: c Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

88) How is class switching accomplished? a) by mutation of the CH gene next to the VDJ gene that was formed previously by DNA rearrangement b) by moving a different CH gene next to the VDJ gene that was formed previously by DNA rearrangement c) by inversion of the CH gene next to the VDJ gene that was formed previously by DNA rearrangement d) by duplicating the CH gene next to the VDJ gene that was formed previously by DNA rearrangement e) by moving a different CH gene next to the VDJ gene that was formed previously by DNA mutation Answer: b Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

89) A helper T cell that secretes ______ induces a switch in the adjacent B cell from IgM synthesis to one of the IgG classes. a) IFN-ɤ b) IFN-α c) IFN-β d) interleukin-1 e) glucagons Answer: a

Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

90) Which of the following individuals would be most likely to donate an organ successfully to another individual? a) any member of the population b) the recipient's sibling c) a member of the same race as the recipient d) the recipient's identical twin e) the recipient's fraternal twin Answer: d Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

91) Which of the following drugs is often used to help prevent rejection of a tissue transplant? a) penicillin b) cycloheximide c) cyclosporin A d) streptomycin e) acetylsalicylic acid Answer: c Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

92) What is the natural function of the MHC proteins? a) attack of bacterial surface antigens b) destruction of transplanted antigens c) involvement in antigen presentation d) involvement in antibody presentation e) maintaining the stability of the plasma membrane Answer: c Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

93) What holds the small peptide fragment of an antigen at the surface of an antigen presenting cell? a) phosphotyrosine motifs b) MHC proteins c) T-cell receptors d) phosphatidylinositol e) B-cell receptors Answer: b Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

94) Possession of the HLA-B*35 MHC allele ________. a) is associated with rapid progression to full-blown AIDS b) correlates with resistance to a certain type of malaria c) correlates with resistance a hepatitis B infection d) correlates with resistance to a certain type of influenza virus e) is associated with extreme susceptibility to the Ebola virus Answer: a

Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

95) Which of the following is a true statement regarding an MHC class II molecule? possesses __________________.

It

a) 1 MHC-encoded polypeptide chain called the heavy chain b) a non-MHC polypeptide associated non-covalently with another subunit c) β2-microglobulin d) heterodimeric structure, with both subunits encoded by MHC alleles e) heterotrimeric structure, with all three subunits encoded by MHC alleles Answer: d Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

96) Antigens that originate within the cytosol of a cell are referred to as __________. a) endogenous proteins b) exogenous proteins c) cytosolic proteins d) phagocytic proteins e) enterogenous proteins Answer: a Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

97) What is responsible for degrading antigens located in the cytosol of antigen-presenting cells into short peptides? a) uncomplexed proteases floating free in the cytoplasm b) proteases that are part of proteasomes c) proteases embedded in the nuclear membrane d) the acidic environment of the lysosome lumen e) hydrolytic enzymes of the lysosomal lumen Answer: b Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

98) MHC class II proteins are synthesized as _____________. a) RER membrane proteins b) RER lumen proteins c) lysosomal membrane proteins d) lysosomal lumen proteins e) mitochondrial membrane proteins Answer: a Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

99) Where are the MHC class I and II proteins thought to separate from one another? a) in the RER b) in the trans-Golgi network (TGN) c) in the cis-Golgi network (CGN) d) in lysosomes e) at the plasma membrane Answer: b

Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

100) What is considered the primary sorting compartment along the MHC biosynthetic pathway? a) the RER b) the trans-Golgi network (TGN) c) the cis-Golgi network (CGN) d) lysosomes e) the plasma membrane Answer: b Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

101) Which of the following is characteristic of immature T cells that have just migrated to the thymus gland from the bone marrow? a) They lack lobed nuclei. b) They lack cell surface proteins that mediate T-cell function, most notably TCRs. c) They possess a diverse population of plasma membrane proteins. d) They have a low amount of RER. e) They have a large number of pseudopodia.

Answer: b Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

102) What happens to T cells whose TCRs are unable to recognize self-MHC complexes? a) They die within the thymus due to a lack of growth signals. b) They die within the bone marrow due to a lack of growth signals. c) They undergo proliferation in the thymus. d) They undergo proliferation in the bone marrow. e) They remain quiescent until further growth factors stimulate their proliferation.

Answer: a Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

103) In some cases, the light chains of autoreactive antibodies can be replaced by a new light chain encoded by an immunoglobulin gene that has been secondarily rearranged in a process called _________. a) receptor rearrangement b) receptor editing c) receptor stimulation d) receptor costimulation e) receptor subtraction Answer: b Difficulty: Easy Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

104) What is interleukin 4 thought to do? a) stimulate the B cell to switch from making IgM class antibodies to IgG or IgE class antibodies b stimulate the B cell to switch from making IgG class antibodies to IgM or IgD class antibodies c) induce proliferation of B cells d) induce differentiation of B cells and secretory B cell activities Answer: a

Difficulty: Medium Learning Objective: LO 17.5 Compare the structures and functions of B and T cell antigen receptors.

Section Reference: Section 17.5 Selected Topics on the Cellular and Molecular Basis of Immunity

105) Chimeric antigen receptors (CARs) have evolved in molecular structure through three generations of design. Which of the following statements regarding the three generations of CARs is correct? a) the first generation CARs were the largest most complex molecules b) the second generation CARs possessed two VH and two VL domains c) the third generation CARs possessed the most costimulatory domains d) the third generation CARs possessed three VH and two VL domains Answer: c Difficulty: Medium Learning Objective: LO 17.6 Describe the clinical use of adoptive T cell therapy.

Section Reference: Section 17.6 Engineering Linkage: Adoptive T Cell Therapy

106) Which is NOT a present-day challenge in the clinical use of adoptive T cell therapy? a) the lack of skilled clinical scientists and prohibitive costs associated with producing the engineered T cells b) unanticipated side effects such as massive cytokine release c) patient remissions after T cell therapies d) the affinity of the T cells for non-cancer cells Answer: a Difficulty: Medium Learning Objective: LO 17.6 Describe the clinical use of adoptive T cell therapy.

Section Reference: Section 17.6 Engineering Linkage: Adoptive T Cell Therapy

107) Which cancer type has shown the best treatment results with adoptive T cell therapies to date? a) lung cancers

b) breast cancer c) melanoma d) B cell leukemia Answer: d Difficulty: Medium Learning Objective: LO 17.6 Describe the clinical use of adoptive T cell therapy.

Section Reference: Section 17.6 Engineering Linkage: Adoptive T Cell Therapy

108) Which of the following signaling components is NOT involved in lymphocyte activation by a B cell or dendritic cell? a) receptor tyrosine kinases b) cytoplasmic tyrosine kinases c) phospholipase C d) MAP kinase Answer: a Difficulty: Medium Learning Objective: LO 17.7 Explain how T cell activation may lead to activation of transcription factors that mediate the immune response.

Section Reference: Section 17.7 Signal Transduction Pathways in Lymphocyte Activation

109) Cytokines utilize a novel signal transduction pathway referred to as the _______ pathway, which operates without the involvement of _________. a) cytokine-specific, receptors b) cytokine-mediated, transducers c) JAK-STAT, second messengers d) JAX-TAT, tyrosine kinases e) Jack Sprat, fats Answer: c Difficulty: Medium Learning Objective: LO 17.7 Explain how T cell activation may lead to activation of transcription factors that mediate the immune response.

Section Reference: Section 17.7 Signal Transduction Pathways in Lymphocyte Activation

Package Title: Test Bank Course Title: Karp 9e Chapter Number: 18

Question Type: Multiple Choice

1) Which part of a microscope is responsible for gathering diffuse rays from the microscope light source and illuminating the specimen with a small cone of bright light? a) condenser lens b) objective lens c) ocular lens d) iris e) focusing knob Answer: a Difficulty: Easy Learning Objective: LO 18.1 Apply the concepts of magnification, resolution, and visibility to light microscopy.

Section Reference: Section 18.1 The Light Microscope

2) The total magnification of a microscope is equal to __________. a) the product of magnification produced individually by the ocular and the condenser lens b) the product of magnification produced individually by the ocular and objective lenses c) the magnification power of the objective lens divided by the numerical aperture d) the magnification power of the ocular lens divided by the numerical aperture e) the magnification power of the objective lens divided by that of the ocular lens Answer: b Difficulty: Easy Learning Objective: LO 18.1 Apply the concepts of magnification, resolution, and visibility to light microscopy.

Section Reference: Section 18.1 The Light Microscope

3) What describes the result of the magnification power of the microscope exceeding the ability of the microscope to resolve? a) empty resolution b) waste c) empty magnification d) refractibility e) birefringence Answer: c Difficulty: Easy Learning Objective: LO 18.1 Apply the concepts of magnification, resolution, and visibility to light microscopy.

Section Reference: Section 18.1 The Light Microscope

4) How does a phase-contract microscope setup make transparent objects more visible? a) It uses brighter bulbs than conventional light microscopes. b) It generates a negative image so that the background is dark and the specimen is light. c) It generates stereo images that can be viewed only with polarized filters. d) It causes direct and refracted light rays to interfere with one another. e) It operates at a lower temperature to reduce random specimen movement.

Answer: d Difficulty: Medium Learning Objective: LO 18.1 Apply the concepts of magnification, resolution, and visibility to light microscopy.

Section Reference: Section 18.1 The Light Microscope

5) Molecules which absorb photons of a specific wavelength and release a portion of the energy in longer wavelengths are called ________. a) fluorophores b) absorbers c) fluorocules d) emitters e) glow molecules Answer: a

Difficulty: Easy Learning Objective: LO 18.1 Apply the concepts of magnification, resolution, and visibility to light microscopy.

Section Reference: Section 18.1 The Light Microscope

6) Which of the following is NOT a commonly used fluorophore? a) GFP b) CFP c) EPuce d) EYFP e) mBanana Answer: c Difficulty: Easy Learning Objective: LO 18.1 Apply the concepts of magnification, resolution, and visibility to light microscopy.

Section Reference: Section 18.1 The Light Microscope

7) Two fluorescent proteins (protein 1 and protein 2) are used in a FRET experiment and are illuminated with light that excites protein 1. If the proteins are close enough for energy transfer to occur, what wavelength(s) of light will be detected? a) The light that excites protein 1 b) The light that is emitted by protein 1 c) The light that excites protein 2 d) The light that is emitted by protein 2 e) No light will be detected, because the fluorescence of proteins 1 and 2 will cancel out Answer: d Difficulty: Medium Learning Objective: LO 18.1 Apply the concepts of magnification, resolution, and visibility to light microscopy.

Section Reference: Section 18.1 The Light Microscope

8) Advanced optical techniques such as stochastic optical reconstruction microscopy (STORM) have lowered the optical microscope resolution limit to less than ________.

a) 0.02 µm b) 0.2 µm c) 2 µm d) 20 µm e) 200 µm Answer: a Difficulty: Easy Learning Objective: LO 18.1 Apply the concepts of magnification, resolution, and visibility to light microscopy.

Section Reference: Section 18.1 The Light Microscope

9) The fluorescence imaging method in which a specimen containing one or more photoswitchable fluorophores is illuminated with pulses of light is known as: a) fluorescence recovery after photobleaching b) laser scanning confocal microscopy c) super-resolution microscopy d) light sheet microscopy e) fluorescence resonance energy transfer Answer: c Difficulty: Easy Learning Objective: LO 18.1 Apply the concepts of magnification, resolution, and visibility to light microscopy.

Section Reference: Section 18.1 The Light Microscope

10) Why do electron microscopes provide much greater resolving power than light microscopes? a) more electrical power is involved in running an electron microscope b) the wavelength of an electron is much smaller than that of visible light c) the wavelength of an electron is much larger than that of visible light d) the numerical aperture is much larger in electron microscopes e) the numerical aperture is much smaller in electron microscopes Answer: b Difficulty: Medium Learning Objective: LO 18.2 Explain how images are produced and specimens are prepared in transmission electron microscopy.

Section Reference: Section 18.2 Transmission Electron Microscopy

11) Why is it that with a standard transmission electron microscope, resolution is actually about two orders of magnitude less than its theoretical limit? a) The lenses of an electron microscope exhibit serious spherical aberration problems, which can be avoided by using a very small N. A. b) The lenses of an electron microscope exhibit serious spherical aberration problems, which can be avoided by using a very large N. A. c) If electron wavelength is too high, spherical aberration distorts the image. d) If electron wavelength is too low, spherical aberration distorts the image.

Answer: a Difficulty: Medium Learning Objective: LO 18.2 Explain how images are produced and specimens are prepared in transmission electron microscopy.

Section Reference: Section 18.2 Transmission Electron Microscopy

12) Of what is the electron source of an electron microscope, the cathode, composed? a) a tungsten wire filament b) an iron wire filament c) a titanium wire filament d) an iron spike filament e) a tungsten depressor filament Answer: a Difficulty: Easy Learning Objective: LO 18.2 Explain how images are produced and specimens are prepared in transmission electron microscopy.

Section Reference: Section 18.2 Transmission Electron Microscopy

13) An electron beam strikes a specimen in an area where there is a high concentration of heavy metal atoms. What does a spot on the phosphorescent screen of the electron microscope just BELOW this part of the specimen look like if compared to the area of the specimen where there is the high concentration of heavy metal atoms? a) It is darker.

b) It is brighter. c) It is speckled. d) It is invisible. e) It is purple.

Answer: b Difficulty: Hard Learning Objective: LO 18.2 Explain how images are produced and specimens are prepared in transmission electron microscopy.

Section Reference: Section 18.2 Transmission Electron Microscopy

14) Good fixatives are chemicals that _______ and ________ cellular macromolecules without producing artifacts. a) precipitate, degrade b) degrade, denature c) denature, precipitate d) denature, polarize e) polarize, precipitate Answer: c Difficulty: Easy Learning Objective: LO 18.2 Explain how images are produced and specimens are prepared in transmission electron microscopy.

Section Reference: Section 18.2 Transmission Electron Microscopy

15) What is NOT an advantage of capturing the image generated by transmission electron microscopy using a CCD video camera? a) It provides an instant image. b) There is no need to develop the image using chemicals. c) The image can be captured at very high resolution. d) Less voltage is required.

Answer: d Difficulty: Medium Learning Objective: LO 18.2 Explain how images are produced and specimens are prepared in transmission electron microscopy.

Section Reference: Section 18.2 Transmission Electron Microscopy

16) How do you prepare tissue for electron microscopy without using fixatives? a) Freeze it gradually over a few hours. b) Freeze it rapidly. c) Subject it to a vacuum rapidly. d) Heat it to dry it rapidly. e) Coat it quickly in heavy metal.

Answer: b Difficulty: Easy Learning Objective: LO 18.2 Explain how images are produced and specimens are prepared in transmission electron microscopy.

Section Reference: Section 18.2 Transmission Electron Microscopy

17) With what molecules in a cell does osmium tetroxide primarily react? a) DNA b) RNA c) fatty acids d) proteins e) carbohydrates Answer: c Difficulty: Easy Learning Objective: LO 18.2 Explain how images are produced and specimens are prepared in transmission electron microscopy.

Section Reference: Section 18.2 Transmission Electron Microscopy

18) What is the name of the special device used to section a frozen block of tissue? a) micrometer b) cryoslicer c) cryomicrotome d) ultratome e) microslicer Answer: c

Difficulty: Easy Learning Objective: LO 18.2 Explain how images are produced and specimens are prepared in transmission electron microscopy.

Section Reference: Section 18.2 Transmission Electron Microscopy

19) The 3-D computerized reconstruction of a cell generated by cryoelectron tomography is called a(n) ________. a) tomatogram b) chromatogram c) tomogram d) telegram e) tonogram Answer: c Difficulty: Easy Learning Objective: LO 18.2 Explain how images are produced and specimens are prepared in transmission electron microscopy.

Section Reference: Section 18.2 Transmission Electron Microscopy

20) Which electron microscope technique is used to create a three-dimensional image of the surfaces of objects ranging in size from a virus to an animal's head? a) positive staining b) negative staining c) scanning electron microscopy d) shadow casting e) freeze-fracture freeze-etch Answer: c Difficulty: Easy Learning Objective: LO 18.3 Compare the methods used in scanning electron microscopy and atomic force microscopy.

Section Reference: Section 18.3 Scanning Electron and Atomic Force Microscopy

21) Why must a specimen that is to be viewed in the SEM be dehydrated before viewing?

a) Water causes the specimen to swell. b) Water distorts the image. c) The specimen will be observed in a vacuum, which would cause the water to freeze. d) The specimen will be observed in a vacuum, which would cause the water to evaporate rapidly and damage the specimen, altering its surface structure. e) Water attracts electrons.

Answer: d Difficulty: Medium Learning Objective: LO 18.3 Compare the methods used in scanning electron microscopy and atomic force microscopy.

Section Reference: Section 18.3 Scanning Electron and Atomic Force Microscopy

22) When specimens are air-dried, what causes the damage that the tissues suffer? a) shrinkage b) swelling c) surface tension at air-water interfaces d) hydrostatic pressure e) air pressure Answer: c Difficulty: Easy Learning Objective: LO 18.3 Compare the methods used in scanning electron microscopy and atomic force microscopy.

Section Reference: Section 18.3 Scanning Electron and Atomic Force Microscopy

23) What method is typically used to dry specimens for scanning electron microscopy? a) air drying b) critical-point drying c) forced air drying d) vacuum drying e) dehydrational drying Answer: b Difficulty: Easy Learning Objective: LO 18.3 Compare the methods used in scanning electron microscopy and atomic force microscopy.

Section Reference: Section 18.3 Scanning Electron and Atomic Force Microscopy

24) Atomic force microscopy can be used for ___________. a) the monitoring and determination of molecular structure b) nanomanipulation to pull or push on a specimen in an attempt to measure various mechanical properties c) determination of the affinity of a receptor for its ligand d) visualization of macromolecular activity over time e) All of these are true.

Answer: e Difficulty: Medium Learning Objective: LO 18.3 Compare the methods used in scanning electron microscopy and atomic force microscopy.

Section Reference: Section 18.3 Scanning Electron and Atomic Force Microscopy

25) A ________ is a substance that reveals its presence in one way or another and thus can be localized or monitored during an experiment. a) trancer b) tracer c) phosphor d) fluor e) trancept Answer: b Difficulty: Easy Learning Objective: LO 18.4 Explain the use of radioisotopes in autoradiography.

Section Reference: Section 18.4 The Use of Radioisotopes

26) What determines the identity and chemical properties of an atom? a) the number of protons in its nucleus b) the number of neutrons in its nucleus c) the number of electrons in its nucleus d) the number of protons in the atom's electron shells e) the number of neutrons in the atom's electron shells

Answer: a Difficulty: Easy Learning Objective: LO 18.4 Explain the use of radioisotopes in autoradiography.

Section Reference: Section 18.4 The Use of Radioisotopes

27) ________ are atoms with the same number of protons but varying numbers of neutrons. a) Isomers b) Isosceles c) Isotopes d) Epitopes e) Haplotypes Answer: c Difficulty: Easy Learning Objective: LO 18.4 Explain the use of radioisotopes in autoradiography.

Section Reference: Section 18.4 The Use of Radioisotopes

28) Which form of radiation is equivalent to a helium atom nucleus? a) an alpha particle b) a delta particle c) a beta particle d) gamma radiation e) an omega particle Answer: a Difficulty: Easy Learning Objective: LO 18.4 Explain the use of radioisotopes in autoradiography.

Section Reference: Section 18.4 The Use of Radioisotopes

29) Which form of radiation is emitted by the most commonly used isotopes and by most biologically important isotopes? a) an alpha particle b) a delta particle

c) a beta particle d) gamma radiation e) an omega particle Answer: c Difficulty: Easy Learning Objective: LO 18.4 Explain the use of radioisotopes in autoradiography.

Section Reference: Section 18.4 The Use of Radioisotopes

30) In which technique is radioactivity detected by mixing the sample in a vial with a special fluid that contains compounds that emit light if struck by a beta particle? a) autoradiography b) an NMR machine c) liquid scintillation spectrometry d) mass spectrometry e) AFM Answer: c Difficulty: Easy Learning Objective: LO 18.4 Explain the use of radioisotopes in autoradiography.

Section Reference: Section 18.4 The Use of Radioisotopes

31) What happens if a photographic emulsion is brought into close contact with a radioactive source in a specimen? a) The emulsion is degraded in places close to a radioactive atom. b) The particles emitted by the source leave tiny, black silver grains in the emulsion after photographic development. c) The particles emitted by the source leave tiny, black potassium grains in the emulsion after photographic development. d) The particles emitted by the source leave tiny, silver carbon grains in the emulsion after photographic development. e) The particles emitted by the source leave tiny, gold atoms in the emulsion after photographic development.

Answer: b Difficulty: Medium Learning Objective: LO 18.4 Explain the use of radioisotopes in autoradiography.

Section Reference: Section 18.4 The Use of Radioisotopes

32) _________ are established with cells that have been frozen in liquid nitrogen, thawed and then placed in a waiting culture medium. a) Primary cultures b) Secondary cultures c) Tertiary cultures d) Supernatant cultures e) Penultimate cultures Answer: b Difficulty: Medium Learning Objective: LO 18.5 Differentiate the uses of a primary cell culture, a secondary cell culture, and a cell line.

Section Reference: Section 18.5 Cell Culture

33) __________ are established with cells that have been obtained directly from the organism; cultures produced from animal cells are usually obtained from ________. a) Primary cultures, embryos b) Secondary cultures, adult organisms c) Primary cultures, adult organisms d) Secondary cultures, embryos e) Secondary cultures, primary cultures Answer: a Difficulty: Medium Learning Objective: LO 18.5 Differentiate the uses of a primary cell culture, a secondary cell culture, and a cell line.

Section Reference: Section 18.5 Cell Culture

34) How do enzymes like trypsin release cells from tissues to create preparations of single cells? a) The enzymes digest extracellular domains of proteins that mediate cell adhesion. b) The enzymes digest intracellular domains of proteins that mediate cell adhesion. c) The enzymes digest intracellular domains of proteins that mediate cytoskeletal function. d) The enzymes digest extracellular domains of proteins that mediate cytoskeletal function.

e) The enzymes digest extracellular domains of proteins that mediate endocytosis.

Answer: a Difficulty: Medium Learning Objective: LO 18.5 Differentiate the uses of a primary cell culture, a secondary cell culture, and a cell line.

Section Reference: Section 18.5 Cell Culture

35) In phage display, the antibody molecule is displayed on the _______. a) inner surface of the viral particle b) outer surface of the viral particle c) viral DNA d) viral RNA e) viral carbohydrates Answer: b Difficulty: Easy Learning Objective: LO 18.18 Explain the generation and use of antibodies in identification, diagnosis, and treatment.

Section Reference: Section 18.18 The Use of Antibodies

36) What typically happens if the cells of a cell line are injected into laboratory animals? a) They become a normal part of the appropriate tissue in the lab animal. b) The cells soon die. c) They typically grow into malignant tumors. d) They typically grow into the appropriate organ. e) They become part of organs.

Answer: c Difficulty: Easy Learning Objective: LO 18.5 Differentiate the uses of a primary cell culture, a secondary cell culture, and a cell line.

Section Reference: Section 18.5 Cell Culture

37) A culture system in which cells are grown in a multi-dimensional matrix consisting of synthetic and/or natural extracellular materials is called a ______. a) three-dimensional culture system b) two-dimensional culture system c) matrix culture system d) secondary culture system e) organic culture system Answer: a Difficulty: Easy Learning Objective: LO 18.5 Differentiate the uses of a primary cell culture, a secondary cell culture, and a cell line.

Section Reference: Section 18.5 Cell Culture

38) When a cell is growing on a culture dish, what is the word that refers to the lower surface of the cell facing toward the substratum? a) anterior b) dorsal c) posterior d) ventral e) caudal Answer: d Difficulty: Easy Learning Objective: LO 18.5 Differentiate the uses of a primary cell culture, a secondary cell culture, and a cell line.

Section Reference: Section 18.5 Cell Culture

39) After plant cells have been separated and grown in culture, they can grow into an undifferentiated clump of cells called a __________. a) callus b) plaque c) blastema d) tumor e) blastula Answer: a

Difficulty: Easy Learning Objective: LO 18.5 Differentiate the uses of a primary cell culture, a secondary cell culture, and a cell line.

Section Reference: Section 18.5 Cell Culture

40) Which of the following is a technique used to isolate a particular organelle in bulk so that its function can be studied or so that an enzyme can be isolated from it? a) differential interference contrast microscopy b) differential centrifugation c) affinity chromatography d) selective precipitation e) autoradiography Answer: b Difficulty: Easy Learning Objective: LO 18.6 Explain how organelles can be isolated using differential centrifugation.

Section Reference: Section 18.6 The Fractionation of a Cell’s Contents by Differential Centrifugation

41) Under what set of circumstances will organelles move to the bottom of a centrifuge tube in a centrifugal field? a) if the organelle is smaller than ribosomes b) if the organelle has too much fat content c) if the organelle is less dense than the surrounding medium d) if the organelle is more dense than the surrounding medium e) if the organelle has less fat content than the surrounding medium Answer: d Difficulty: Easy Learning Objective: LO 18.6 Explain how organelles can be isolated using differential centrifugation.

Section Reference: Section 18.6 The Fractionation of a Cell’s Contents by Differential Centrifugation

42) What technique distributes the contents of a homogenate into various layers according to the components' densities? a) sucrose density gradient centrifugation b) sucrose density chromatography c) isoelectric density focusing d) liquid scintillation spectrometry e) autoradiography Answer: a Difficulty: Easy Learning Objective: LO 18.6 Explain how organelles can be isolated using differential centrifugation.

Section Reference: Section 18.6 The Fractionation of a Cell’s Contents by Differential Centrifugation

43) What is required in order to study a protein's fine structure or function? a) It must be isolated in a relatively pure state. b) It must be observed in a light microscope. c) It must be denatured. d) It must be enzymatically degraded. e) It must be fixed.

Answer: a Difficulty: Easy Learning Objective: LO 18.7 Outline the various procedures for isolating pure cellular proteins.

Section Reference: Section 18.7 Isolation, Purification, and Fractionation of Proteins

44) What is the general term used to describe a variety of techniques in which a mixture of dissolved components is separated as it moves through a porous matrix? a) electrophoresis b) isoelectric focusing c) chromatography d) selective precipitation e) sucrose density centrifugation Answer: c

Difficulty: Easy Learning Objective: LO 18.7 Outline the various procedures for isolating pure cellular proteins.

Section Reference: Section 18.7 Isolation, Purification, and Fractionation of Proteins

45) A solvent passes through a column and is collected as it drips out of the bottom of the column into a series of tubes; each of these tubes is called ____________. a) an elutant b) a fractal c) a diluent d) a fraction e) a digest Answer: d Difficulty: Easy Learning Objective: LO 18.7 Outline the various procedures for isolating pure cellular proteins.

Section Reference: Section 18.7 Isolation, Purification, and Fractionation of Proteins

46) The first fully human antibody has been manufactured using bacteriophage rather than hybridomas; it is approved for rheumatoid arthritis treatment and is called _________. a) Phagoma b) Humira c) Humana d) Humantibody e) Amana Answer: b Difficulty: Easy Learning Objective: LO 18.18 Explain the generation and use of antibodies in identification, diagnosis, and treatment.

Section Reference: Section 18.18 The Use of Antibodies

47) For each protein, there is a pH at which negative and positive charges are equal. This pH is referred to as the ___________. a) pH point b) neutralization point

c) isometric point d) isoelectric point e) isotonic point Answer: d Difficulty: Easy Learning Objective: LO 18.7 Outline the various procedures for isolating pure cellular proteins.

Section Reference: Section 18.7 Isolation, Purification, and Fractionation of Proteins

48) Which of the following is most likely to elute first from a gel filtration column if each of them is essentially globular? a) a 250 kilodalton protein b) a 120 kilodalton protein c) a chromate ion d) a 12 kilodalton protein e) an 80 kilodalton protein Answer: a Difficulty: Medium Learning Objective: LO 18.7 Outline the various procedures for isolating pure cellular proteins.

Section Reference: Section 18.7 Isolation, Purification, and Fractionation of Proteins

49) In the yeast two-hybrid assay, the _________ domain and the _________ domain of a transcription factor are fused to two different proteins. If the proteins interact with each other, the transcription factor can allow reporter gene expression. a) DNA binding, activation b) DNA binding, inhibition c) regulation, activation d) fish, bait e) upper, lower Answer: a Difficulty: Medium Learning Objective: LO 18.7 Outline the various procedures for isolating pure cellular proteins.

Section Reference: Section 18.7 Isolation, Purification, and Fractionation of Proteins

50) What is the name of the procedure in which proteins separated on a polyacrylamide gel are transferred with the application of a current to a nitrocellulose filter placed against the gel and subsequently identified by their interaction with specific antibodies? a) a Southern blot b) a Northern blot c) an Eastern blot d) a Western blot e) an East Northeastern blot Answer: d Difficulty: Easy Learning Objective: LO 18.7 Outline the various procedures for isolating pure cellular proteins.

Section Reference: Section 18.7 Isolation, Purification, and Fractionation of Proteins

51) Non-denaturing gel electrophoresis (PAGE) has the disadvantage that it ____________. a) separates solely on the basis of charge b) allows the detection of proteins in a gel by their biological activity c) separates on the basis of more than one property thus to some degree confusing the results d) separates solely on the basis of molecular weight e) separates on the basis of molecular weight and frictional coefficient Answer: c Difficulty: Hard Learning Objective: LO 18.7 Outline the various procedures for isolating pure cellular proteins.

Section Reference: Section 18.7 Isolation, Purification, and Fractionation of Proteins

52) Which technique can be used for molecular weight (mass) determinations in proteins? a) X- ray diffraction b) chromatofocusing c) diethylaminoethyl (DEAE) cellulose chromatography d) affinity chromatography e) SDS-PAGE Answer: e Difficulty: Medium

Learning Objective: LO 18.7 Outline the various procedures for isolating pure cellular proteins.

Section Reference: Section 18.7 Isolation, Purification, and Fractionation of Proteins

53) If you are illuminating a specimen with ultraviolet light, into what kind of container should it be placed to make a measurement in a spectrophotometer? a) in a basinette b) in a special, flat-sided quartz container c) in a borosilicate glass tube d) in a special, flat-sided glass container e) in a special, flat-sided plastic container Answer: b Difficulty: Medium Learning Objective: LO 18.7 Outline the various procedures for isolating pure cellular proteins.

Section Reference: Section 18.7 Isolation, Purification, and Fractionation of Proteins

54) The amount of light passing through a solution unabsorbed (or _________) is measured by a ___________ on the other side of the cuvette. a) transmitted, thermocouplers b) absorbed, thermocouplers c) transmitted, photosensor d) absorbed, photosensor e) transmitted, charged coupling devices Answer: c Difficulty: Medium Learning Objective: LO 18.7 Outline the various procedures for isolating pure cellular proteins.

Section Reference: Section 18.7 Isolation, Purification, and Fractionation of Proteins

55) How are fragments already in a mass spectrometer further fragmented? a) injection of pepsin b) injection of more trypsin c) collision of peptides with an inert gas d) collision of peptides with nitrogen gas e) collision of peptides with oxygen

Answer: c Difficulty: Easy Learning Objective: LO 18.7 Outline the various procedures for isolating pure cellular proteins.

Section Reference: Section 18.7 Isolation, Purification, and Fractionation of Proteins

56) To what are the reflection positions and intensities on the photographic plate of an X-ray crystallography experiment related? a) proton densities of proteins b) neutron densities of proteins c) electron densities of proteins d) proton densities of nucleic acids e) neutron densities of lipids Answer: c Difficulty: Medium Learning Objective: LO 18.8 Outline the methods for determining the structures of proteins and multisubunit complexes.

Section Reference: Section 18.8 Determining the Structure of Proteins and Multisubunit Complexes

57) Electron cryomicroscopy can be used to cause membrane proteins to become closely packed at very low temperatures into two-dimensional crystalline arrays within the plane of a membrane.

The structures of such proteins are then determined from combined, high-resolution electron microscope images of many different protein molecules taken at various angles. This process is called __________. a) cryopreservation b) electron crystallography c) cryohistology d) electron cryocrystallography e) proton microscopy Answer: b Difficulty: Easy Learning Objective: LO 18.8 Outline the methods for determining the structures of proteins and multisubunit complexes.

Section Reference: Section 18.8 Determining the Structure of Proteins and Multisubunit Complexes

58) For higher resolution cryo-EM studies, what has replaced the use of negatively stained specimens? a) frozen-dehyhdrated particles b) positively stained specimens c) frozen-hydrated particles d) neutrally stained specimens Answer: c Difficulty: Easy Learning Objective: LO 18.8 Outline the methods for determining the structures of proteins and multisubunit complexes.

Section Reference: Section 18.8 Determining the Structure of Proteins and Multisubunit Complexes

59) Which technique depends on the use of antibodies made specifically against a particular protein (antigen) and then conjugated to a substance that makes the antibodies visible under the light or electron microscope? a) immunolocalization b) immunocompetence c) immunization d) immunofenestration e) negative staining Answer: a Difficulty: Easy Learning Objective: LO 18.18 Explain the generation and use of antibodies in identification, diagnosis, and treatment.

Section Reference: Section 18.18 The Use of Antibodies

60) Why have frozen-hydrated particles largely replaced negatively stained specimens for high resolution cryo-EM studies? a) Frozen-hydrated particles are more likely to generate artifacts. b) Frozen-hydrated particles are much less likely to generate artifacts.

c) Frozen-hydrated particles take positively charged stains more efficiently d) Frozen-hydrated particles are much better suited for the study of external features within the particle's structure.

Answer: b Difficulty: Medium Learning Objective: LO 18.8 Outline the methods for determining the structures of proteins and multisubunit complexes.

Section Reference: Section 18.8 Determining the Structure of Proteins and Multisubunit Complexes

61) In what medium are small RNAs or DNAs of a few hundred nucleotides typically separated through electrophoresis? a) agarose b) polyacrylamide c) cellulose d) paper e) dextran Answer: b Difficulty: Easy Learning Objective: LO 18.9 Explain strategies used to separate nucleic acids based on their molecular features.

Section Reference: Section 18.9 Fractionation of Nucleic Acids

62) What does the change in field direction in pulsed field electrophoresis accomplish? a) It makes the DNA molecules move faster. b) It causes the DNA molecules to reorient themselves during their migration. c) It causes the DNA molecules to denature. d) It causes the DNA molecules to renature. e) It causes the stain to adhere better to the DNA molecules.

Answer: b Difficulty: Easy Learning Objective: LO 18.9 Explain strategies used to separate nucleic acids based on their molecular features.

Section Reference: Section 18.9 Fractionation of Nucleic Acids

63) Pulsed-field electrophoresis is typically used to separate what molecules? a) small DNA molecules b) very small DNA molecules a) proteins smaller than 25,000 daltons b) proteins larger than 25,000 daltons c) DNA molecules greater than about 25 kb d) DNA molecules smaller than about 25 kb Answer: c Difficulty: Easy Learning Objective: LO 18.9 Explain strategies used to separate nucleic acids based on their molecular features.

Section Reference: Section 18.9 Fractionation of Nucleic Acids

64) How sensitive is gel electrophoresis when it is used to separate DNA? a) It can separate fragments of DNA that differ grossly in size. b) It can separate really big DNAs from very small DNAs. c) It can separate DNAs that differ by hundreds of nucleotides. d) It can separate DNA molecules that vary in length by only a single nucleotide. e) It can separate DNA molecules that vary in length by five or more nucleotides.

Answer: d Difficulty: Medium Learning Objective: LO 18.9 Explain strategies used to separate nucleic acids based on their molecular features.

Section Reference: Section 18.9 Fractionation of Nucleic Acids

65) How can a researcher visualize the DNA fragments separated in an electrophoresis gel? a) using a labeled probe with a sequence complementary to the desired DNA fragment b) staining with ethidium bromide c) staining with potassium chloride d) using labeled antibodies e) staining with Coomassie Blue

Answer: b Difficulty: Easy Learning Objective: LO 18.9 Explain strategies used to separate nucleic acids based on their molecular features.

Section Reference: Section 18.9 Fractionation of Nucleic Acids

66) Under what circumstances will a component in a solution or a suspension sediment through a centrifugal field? a) if it has a greater density than the surrounding medium b) if it has a lower density than the surrounding medium c) if it is wet d) if the surrounding medium is denser than the component e) if the component and the surrounding medium have equal density Answer: a Difficulty: Easy Learning Objective: LO 18.9 Explain strategies used to separate nucleic acids based on their molecular features.

Section Reference: Section 18.9 Fractionation of Nucleic Acids

67) Why does the S value alone not provide a measure of molecular mass? a) It is too difficult to measure. b) The speed with which a particle travels through a liquid column is not uniform. c) The velocity at which a particle moves through a liquid column depends on a number of factors, including shape. d) The velocity of movement accelerates as the particle approaches the bottom of the tube. e) The velocity of movement slows up as the particle approaches the top of the tube.

Answer: c Difficulty: Medium Learning Objective: LO 18.9 Explain strategies used to separate nucleic acids based on their molecular features.

Section Reference: Section 18.9 Fractionation of Nucleic Acids

68) How do DNA molecules place themselves in a CsCl equilibrium gradient?

a) They continuously move toward the bottom of the gradient. b) They stop momentarily at the point in the gradient equaling their buoyant density. c) They continuously move toward the top of the gradient. d) They stop permanently at the point in the gradient equaling their buoyant density. e) All DNA molecules localize at the same point in the gradient.

Answer: d Difficulty: Easy Learning Objective: LO 18.9 Explain strategies used to separate nucleic acids based on their molecular features.

Section Reference: Section 18.9 Fractionation of Nucleic Acids

69) Nucleic acid hybridization techniques are based on the observation that ______________. a) DNA can be very long b) two single-stranded nucleic acid molecules of complementary base sequence can form a double-stranded hybrid c) DNA molecules are very hydrophobic d) two single-stranded nucleic acid molecules of any base sequence can form a double-stranded hybrid e) two double-stranded nucleic acid molecules of complementary base sequence can form a double-stranded hybrid Answer: b Difficulty: Medium Learning Objective: LO 18.10 Identify two types of information that can be obtained from nucleic acid hybridizaton.

Section Reference: Section 18.10 Nucleic Acid Hybridization

70) How are double-stranded hybrids released from hydroxylapatite columns? a) by increasing elution buffer concentration b) by decreasing elution buffer concentration c) by increasing pH d) by decreasing pH e) by increasing sucrose concentration Answer: a

Difficulty: Easy Learning Objective: LO 18.10 Identify two types of information that can be obtained from nucleic acid hybridizaton.

Section Reference: Section 18.10 Nucleic Acid Hybridization

71) What is the name of the procedure in which single-stranded DNA molecules are separated by electrophoresis, immobilized on a nitrocellulose filter and then hybridized with labeled, single-stranded DNA probes? a) Southern blot b) Northern blot c) Western blot d) Southwestern blot e) Eastern blot Answer: a Difficulty: Easy Learning Objective: LO 18.10 Identify two types of information that can be obtained from nucleic acid hybridizaton.

Section Reference: Section 18.10 Nucleic Acid Hybridization

72) How are probes labeled with a radioactive isotope detected? a) autoradiography b) fluorescence c) by changing colors d) SEM e) TEM Answer: a Difficulty: Easy Learning Objective: LO 18.10 Identify two types of information that can be obtained from nucleic acid hybridizaton.

Section Reference: Section 18.10 Nucleic Acid Hybridization

73) When DNA molecules from two different organisms are incubated together, some duplexes are formed by DNA strands from the two species. What indicates that such duplexes are less stable than those between strands from the same organism?

a) Heterogeneous duplexes melt at lower temperatures than homogeneous duplexes. b) Heterogeneous duplexes melt at higher temperatures than homogeneous duplexes. c) Heterogeneous duplexes are degraded faster. d) Heterogeneous duplexes are degraded more slowly. e) There is no difference in stability between homogeneous and heterogeneous duplexes.

Answer: a Difficulty: Medium Learning Objective: LO 18.10 Identify two types of information that can be obtained from nucleic acid hybridizaton.

Section Reference: Section 18.10 Nucleic Acid Hybridization

74) A term to describe short, single-stranded nucleic acid molecules is _________. a) mininucleotides b) micronucleotides c) polynucleotides d) oligonucleotides Answer: d Difficulty: Easy Learning Objective: LO 18.11 Explain the usefulness of oligonucleotide synthesis in research.

Section Reference: Section 18.11 Chemical Synthesis of DNA

75) Nowadays, what is the most common method for synthesizing double-stranded molecules of DNA for use in experimental procedures? a) by insertion into bacterial cells b) by insertion into bacteriophage c) by automated synthesis of two single stranded DNAs, followed by hybridization d) in quartz cuvettes e) by insertion into fungi Answer: c Difficulty: Easy Learning Objective: LO 18.11 Explain the usefulness of oligonucleotide synthesis in research.

Section Reference: Section 18.11 Chemical Synthesis of DNA

76) What is the term used to describe a piece of DNA containing sequences derived from more than one organism? a) combinational DNA b) recombinant DNA c) combined DNA d) cloned DNA e) recreational DNA Answer: b Difficulty: Easy Learning Objective: LO 18.12 Outline the steps in the production of recombinant DNA. Section Reference: Section 18.12 Recombinant DNA Technology

77) How big are the sites recognized by most restriction enzymes? a) 4 – 6 nucleotides b) 6 – 8 nucleotides c) 2 – 4 nucleotides d) 8 – 10 nucleotides e) 10– 12 nucleotides Answer: a Difficulty: Easy Learning Objective: LO 18.12 Outline the steps in the production of recombinant DNA. Section Reference: Section 18.12 Recombinant DNA Technology

78) A small, circular, double-stranded DNA molecule that is separate from the main bacterial chromosome is called a ___________. a) circuloid b) nucleoid c) plasmid d) palmid e) plummet Answer: c

Difficulty: Easy Learning Objective: LO 18.12 Outline the steps in the production of recombinant DNA. Section Reference: Section 18.12 Recombinant DNA Technology

79) What is the technique for producing millions of copies of recombinant DNA with a specific DNA sequence in a short period of time from one or a few initial copies? a) DNA reproduction b) DNA cloning c) DNA replication d) DNA transcription e) DNA copying Answer: b Difficulty: Easy Learning Objective: LO 18.12 Outline the steps in the production of recombinant DNA. Section Reference: Section 18.12 Recombinant DNA Technology

80) During the gene cloning procedure, what is the purpose of inserting genes into a bacterium that give it resistance to antibiotics? a) Antibiotic resistance allows researchers to select for those cells that contain a plasmid. b) Antibiotic resistance allows researchers to kill those cells that contain a recombinant plasmid. c) Antibiotic resistance increases the generation time of the bacteria. d) Antibiotic resistance decreases bacterial generation time.

Answer: a Difficulty: Medium Learning Objective: LO 18.12 Outline the steps in the production of recombinant DNA. Section Reference: Section 18.12 Recombinant DNA Technology

81) Which of the following is a technique used to encourage bacteria to take up DNA from the surrounding culture medium? a) pretreatment of bacteria with a brief heat shock, followed by exposure to Ca2+ ions b) pretreatment of bacteria with Cu2+ ions, followed by a brief heat shock c) pretreatment of bacteria with Ca2+ ions, followed by a brief heat shock d) pretreatment of bacteria with Ca2+ ions, followed by a brief cold shock

e) pretreatment of bacteria with a brief heat shock, followed by exposure to Mg2+ ions Answer: c Difficulty: Medium Learning Objective: LO 18.12 Outline the steps in the production of recombinant DNA. Section Reference: Section 18.12 Recombinant DNA Technology

82) What is the name of the process by which recombinant DNA gets into bacteria after being picked up from the surrounding medium? a) transduction b) transmutation c) transformation d) transjunction e) transition Answer: c Difficulty: Easy Learning Objective: LO 18.12 Outline the steps in the production of recombinant DNA. Section Reference: Section 18.12 Recombinant DNA Technology

83) What step must first be carried out before RNA templates can be amplified? a) Denaturation must be carried out first. b) They must first be converted to complementary DNAs using DNA polymerase. c) They must first be converted to complementary RNAs using RNA polymerase. d) They must first be converted to complementary DNAs using reverse transcriptase. e) They must first be converted to complementary DNAs using Taq polymerase.

Answer: d Difficulty: Medium Learning Objective: LO 18.13 Describe the process and applications of PCR. Section Reference: Section 18.13 Enzymatic Amplification of DNA by PCR

84) PCR employs a heat-stable DNA polymerase called ________, originally isolated from a bacterium that lives in hot springs at temperatures higher than 90°C.

a) DNA polymerase I b) reverse transcriptase c) Taq polymerase d) poly(A) polymerase Answer: c Difficulty: Easy Learning Objective: LO 18.13 Describe the process and applications of PCR. Section Reference: Section 18.13 Enzymatic Amplification of DNA by PCR

85) What device is used to automatically change the temperature of the PCR reaction mixture, allowing each step in the cycle to take place? a) a water bath b) a thermal cycler c) an ice bucket d) a thermocoupler e) a thermometer Answer: b Difficulty: Easy Learning Objective: LO 18.13 Describe the process and applications of PCR. Section Reference: Section 18.13 Enzymatic Amplification of DNA by PCR

86) If two DNA samples are exactly the same, what would you expect to happen if you exposed both to the same mixture of primers and then carried out the polymerase chain reaction (PCR)? a) No PCR will occur. b) The PCR products should be exactly the same. c) There should be differences in the nature of the PCR products. d) All PCR products in one of the samples will be destroyed. e) All PCR products in one of the samples will be methylated.

Answer: b Difficulty: Medium Learning Objective: LO 18.13 Describe the process and applications of PCR. Section Reference: Section 18.13 Enzymatic Amplification of DNA by PCR

87) In the PCR quantification procedure involving molecular beacons, what causes the fluorochrome to fluoresce? a) The degradation of the reporter oligonucleotide by DNA polymerase endonuclease activity degrades the fluorochrome. b) The degradation of the reporter oligonucleotide by DNA polymerase exonuclease activity separates the fluorochrome from the quencher. c) The degradation of the reporter oligonucleotide by DNA polymerase exonuclease activity degrades the fluorochrome. d) The degradation of the reporter oligonucleotide by DNA polymerase endonuclease activity separates the fluorochrome from the quencher. e) DNA polymerase combines the fluorochrome and the quencher.

Answer: b Difficulty: Medium Learning Objective: LO 18.13 Describe the process and applications of PCR. Section Reference: Section 18.13 Enzymatic Amplification of DNA by PCR

88) How are DNA molecules fragmented during sequencing procedures? a) by acid hydrolysis b) by basic condensation c) using restriction enzymes d) using DNA polymerase I e) by sonicating the sample Answer: c Difficulty: Easy Learning Objective: LO 18.14 Compare the Sanger-Coulson process of DNA sequencing, to second and third generation sequencing.

Section Reference: Section 18.14 DNA Sequencing

89) When malignant myeloma cells and normal lymphocytes are fused together to make hybrid cells, the cells thus produced are called _________. a) lymphomas b) antibomas c) hybridomas d) myelobrids

e) lymphocytomas Answer: c Difficulty: Easy Learning Objective: LO 18.18 Explain the generation and use of antibodies in identification, diagnosis, and treatment.

Section Reference: Section 18.18 The Use of Antibodies

90) Which method combines PCR with the Sanger-Coulson sequencing method and is widely used in genome sequencing? a) the Sanger-PCR method b) DNA cloning c) the cycle sequencing method d) the Sanger-Gilbert method e) the Maxam-Coulson method Answer: c Difficulty: Medium Learning Objective: LO 18.14 Compare the Sanger-Coulson process of DNA sequencing, to second and third generation sequencing.

Section Reference: Section 18.14 DNA Sequencing

91) If the template in the cycle sequencing method is a PCR product, what is generally used as a primer? a) both PCR primers b) randomly generated primers c) only one of the PCR primers d) any primer except the PCR primers e) poly(A) oligonucleotides Answer: c Difficulty: Medium Learning Objective: LO 18.14 Compare the Sanger-Coulson process of DNA sequencing, to second and third generation sequencing.

Section Reference: Section 18.14 DNA Sequencing

92) What is used to separate DNA fragments in the cycle sequencing method of DNA sequencing in such a way that chains differing by only one nucleotide in length can be separated? a) SDS-PAGE b) non-denaturing PAGE c) agarose gel electrophoresis d) electrophoresis on very thin capillary gels e) gel filtration chromatography Answer: d Difficulty: Easy Learning Objective: LO 18.14 Compare the Sanger-Coulson process of DNA sequencing, to second and third generation sequencing.

Section Reference: Section 18.14 DNA Sequencing

93) In the cycle sequencing method, how is the sequence of the DNA determined? a) from autoradiograms b) from the order of fluorescent colors in the capillary gel c) from the overall color of the gel d) from the amount of heavy nitrogen in each band on the gel e) from the absorbance read in the spectrophotometer Answer: b Difficulty: Easy Learning Objective: LO 18.14 Compare the Sanger-Coulson process of DNA sequencing, to second and third generation sequencing.

Section Reference: Section 18.14 DNA Sequencing

94) Which of the following is a feature of “third generation” sequencers? a) sequencing of single molecules without amplification b) generation of long reads of 1000 nucleotides or more c) laser-based detection of nucleotide incorporation d) identification of single nucleotides passing through nanopores e) all of these are correct Answer: e

Difficulty: Medium Learning Objective: LO 18.14 Compare the Sanger-Coulson process of DNA sequencing, to second and third generation sequencing.

Section Reference: Section 18.14 DNA Sequencing

95) A collection of cloned DNA fragments is called a _________. a) DNA collection b) DNA file c) DNA library d) DNA biblion e) DNA codon Answer: c Difficulty: Easy Learning Objective: LO 18.15 Differentiate a genomic library and a cDNA library.

Section Reference: Section 18.15 DNA Libraries

96) What is the result of treating the full complement of genomic DNA with low concentrations of restriction enzymes under conditions in which most of the susceptible sites are not cleaved? a) The genomic DNA is fragmented into a defined and limited set of fragments. b) The genomic DNA is fully degraded. c) The genomic DNA is barely damaged. d) The genomic DNA is cut into random fragments of many different sizes. e) The genomic DNA is fragmented into a small set of very large pieces of DNA. Answer: d Difficulty: Hard Learning Objective: LO 18.15 Differentiate a genomic library and a cDNA library.

Section Reference: Section 18.15 DNA Libraries

97) What size, on average. are the DNA fragments that can be placed into phage λ and cloned? a) 15 kb in length b) 20 kb in length c) 50 kb in length d) 100 kb in length

e) 10 kb in length Answer: b Difficulty: Easy Learning Objective: LO 18.15 Differentiate a genomic library and a cDNA library.

Section Reference: Section 18.15 DNA Libraries

98) What does cloning of cDNAs allow? a) the determination of all genes present in a cell b) the identification of sequences active at a given time in a particular cell type c) the identification of genes active throughout an organism's body d) the sequence of all genes present in a given cell e) the sequences of all cellular introns Answer: b Difficulty: Medium Learning Objective: LO 18.15 Differentiate a genomic library and a cDNA library.

Section Reference: Section 18.15 DNA Libraries

99) Which enzyme is used to replace the RNA of a DNA-RNA hybrid with DNA during the preparation of a cDNA library? a) RNase H b) reverse transcriptase c) DNA polymerase I d) RNase K e) DNA ligase Answer: c Difficulty: Easy Learning Objective: LO 18.15 Differentiate a genomic library and a cDNA library.

Section Reference: Section 18.15 DNA Libraries

100) What term defines viral-mediated gene transfer, which is a very widely used strategy to get genes into eukaryotic cells?

a) transduction b) transfection c) electroporation d) lipofection e) transgenics Answer: a Difficulty: Easy Learning Objective: LO 18.16 Explain how foreign DNA can be introduced into cells to form transgenic animals and plants.

Section Reference: Section 18.16 DNA Transfer into Eukaryotic Cells and Mammalian Embryos

101) Why have most clinical trials in which retroviruses have been used to introduce genes for the purpose of gene therapy in patients lacking that gene been unsuccessful? a) Viral DNA is more unstable than mammalian DNA. b) Current viral vectors have too high an infection efficiency rate. c) Current viral vectors have too low an infection efficiency rate. d) Mammalian DNA is more unstable than viral DNA. e) Current viral vectors tend to cause serious diseases.

Answer: c Difficulty: Easy Learning Objective: LO 18.16 Explain how foreign DNA can be introduced into cells to form transgenic animals and plants.

Section Reference: Section 18.16 DNA Transfer into Eukaryotic Cells and Mammalian Embryos

102) In which method of transfection are cells treated with DNA that is bound to positively charged lipids, called cationic liposomes, that are capable of fusing with the lipid bilayer of the cell membrane and delivering the DNA to the cytoplasm? a) transduction b) transfection c) electroporation d) lipofection e) transgenics Answer: d Difficulty: Easy

Learning Objective: LO 18.16 Explain how foreign DNA can be introduced into cells to form transgenic animals and plants.

Section Reference: Section 18.16 DNA Transfer into Eukaryotic Cells and Mammalian Embryos

103) Microinjection is a technique in which ____________. a) mRNAs are injected directly into the cell nucleus. b) DNA is injected directly into the cell nucleus. c) DNA is injected directly into the mitochondria. d) DNA is injected directly into the cell cytoplasm. e) DNA is injected directly into phagosomes.

Answer: b Difficulty: Medium Learning Objective: LO 18.16 Explain how foreign DNA can be introduced into cells to form transgenic animals and plants.

Section Reference: Section 18.16 DNA Transfer into Eukaryotic Cells and Mammalian Embryos

104) What presently supplies reduced nitrogen compounds to crop plants that are unable to fix nitrogen from the atmosphere on their own? a) phosphates b) water c) fertilizers d) soil e) sunlight Answer: c Difficulty: Easy Learning Objective: LO 18.16 Explain how foreign DNA can be introduced into cells to form transgenic animals and plants.

Section Reference: Section 18.16 DNA Transfer into Eukaryotic Cells and Mammalian Embryos

105) The process of learning about genotypes by studying mutant phenotypes is called ________. a) reverse genetics b) forward genetics

c) backwards genetics d) frontwards genetics e) proverse genetics Answer: b Difficulty: Easy Learning Objective: LO 18.17 Describe four mechanisms of the introduction of specific mutations into genes in vitro.

Section Reference: Section 18.17 Gene Editing and Silencing

106) What method introduces new variants into a population that may or may not affect the gene being studied? a) directed mutation b) replication c) random mutation d) evolution e) intelligent design Answer: c Difficulty: Easy Learning Objective: LO 18.17 Describe four mechanisms of the introduction of specific mutations into genes in vitro.

Section Reference: Section 18.17 Gene Editing and Silencing

107) If you do site-directed mutagenesis of the coding region of a gene, which of the following is most likely to happen? a) The rate of gene expression slows down. b) The rate of gene expression speeds up. c) The protein's structure and function are altered. d) The protein's structure and function remain unaltered.

Answer: c Difficulty: Medium Learning Objective: LO 18.17 Describe four mechanisms of the introduction of specific mutations into genes in vitro.

Section Reference: Section 18.17 Gene Editing and Silencing

108) A gene sequence is cut at a restriction site and DNA polymerase is then used to make the single-stranded regions of the sticky ends into double-stranded DNA. The ends of the altered DNA are then ligated back together. What is the effect on the gene sequence? a) Its amino acids remain constant b) The reading frame of the gene is destroyed. c) The gene is unchanged. d) The gene is transposed. e) The gene is inverted.

Answer: b Difficulty: Medium Learning Objective: LO 18.17 Describe four mechanisms of the introduction of specific mutations into genes in vitro.

Section Reference: Section 18.17 Gene Editing and Silencing

109) The _______ of mammals is an early embryonic developmental stage comparable to the blastula stage in other animals. a) blastoderm b) fetus c) blastocyst d) trophectoderm e) inner cell mass Answer: c Difficulty: Easy Learning Objective: LO 18.17 Describe four mechanisms of the introduction of specific mutations into genes in vitro.

Section Reference: Section 18.17 Gene Editing and Silencing

110) Antibodies can distinguish between two polypeptides that differ by as little as __________. a) one amino acid b) two amino acids c) five amino acids d) one nucleotide e) two nucleotides

Answer: a Difficulty: Medium Learning Objective: LO 18.18 Explain the generation and use of antibodies in identification, diagnosis, and treatment.

Section Reference: Section 18.18 The Use of Antibodies

111) Whole blood from an animal that has been exposed to foreign materials (antigens) and then had the cells and clotting factors removed from it is called _________. a) antibodies b) antigenic syrup c) antiserum d) immune serum e) serosal secretions Answer: c Difficulty: Easy Learning Objective: LO 18.18 Explain the generation and use of antibodies in identification, diagnosis, and treatment.

Section Reference: Section 18.18 The Use of Antibodies

112) Antibodies made by a clone of antibody-producing cells derived from a single B lymphocyte have _________; individual B cell clones which respond to the same antigen have membrane-bound antibodies with an affinity for __________. a) identical antigen-combining sites, different parts of the antigen b) variable antigen-combining sites, the same part of the antigen c) identical antigen-combining sites, the same part of the antigen d) variable antigen-combining sites, different parts of the antigen e) different antigen-binding sites, the cell membrane Answer: a Difficulty: Hard Learning Objective: LO 18.18 Explain the generation and use of antibodies in identification, diagnosis, and treatment.

Section Reference: Section 18.18 The Use of Antibodies

113) An antibody preparation made by a single colony or clone of antibody-producing cells would consist of large quantities of antibodies that all had exactly the same antigen-combining site. Such antibodies would be called _________ antibodies. a) polyclonal b) monoclonal c) polyvalent d) monotreme e) monocular Answer: b Difficulty: Easy Learning Objective: LO 18.18 Explain the generation and use of antibodies in identification, diagnosis, and treatment.

Section Reference: Section 18.18 The Use of Antibodies