TEST BANK for Nester's Microbiology: A Human Perspective 10th Edition by Denise Anderson, Sarah Salm by welldoneassistant

CHAPTER 1 TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Spontaneous generation refers to the idea that organisms came from other organisms. ⊚ ⊚

true false

The human body only contains bacteria during illness. ⊚ ⊚

true false

Bacteria and eukarya both contain membrane-bound organelles. ⊚ true ⊚ false

The scientific name of an organism indicates its domain. ⊚ ⊚

true false

Viroids are naked (lacking a protein shell) pieces of RNA that infect plants. ⊚ ⊚

true false

Viruses simultaneously contain DNA, RNA, and protein. ⊚ true ⊚ false

Viruses, viroids, and prions are obligate intracellular agents. ⊚ ⊚

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true false

Viruses and bacteria are both unicellular. ⊚ ⊚

true false

An organism is categorized in a domain according to its cell size. ⊚ ⊚

true false

10)

Archaea are very similar to bacteria and have rigid cell walls made of peptidoglycan. ⊚ true ⊚ false

11)

Thiomargarita namibiensis cannot be a eukaryote because it is only 1 mm in width. ⊚ true ⊚ false

MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 12) The scientist usually credited with seeing the first microorganisms, which he called "animalcules", was ______. A) Redi B) van Leeuwenhoek C) Pasteur D) Tyndall E) Lister

13)

The word "animalcule" was first used by ______.

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A) Pasteur B) Redi C) van Leeuwenhoek D) Tyndall E) Hooke

14)

The idea of spontaneous generation postulated that A) organisms could evolve into the next generation of organisms. B) organisms could spontaneously turn into other types of organisms. C) living organisms could spontaneously arise from non-living material. D) living organisms could spontaneously arise from other living organisms. E) living organisms must contain at least ten cells.

15) Which of these scientists were involved in investigating the idea of spontaneous generation? A) Redi and van Leeuwenhoek B) Redi and Pasteur C) van Leeuwenhoek and Pasteur D) Pasteur and Escherich E) Escherich and Redi

16)

The work of Tyndall and Cohn

A) supported the idea of spontaneous generation rather than the idea of biogenesis. B) explained why some spontaneous generation investigators got different results from those of Pasteur. C) showed that all microbes caused spontaneous disease if they enter the human body. D) allowed scientists to see microorganisms (called "animalcules") using a simple microscope. E) showed that boiling fails to kill vegetative bacteria, leading to biogenesis.

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17) The structures present in the hay infusions used in experiments on spontaneous generation that made them difficult to sterilize are _____. A) chloroplasts B) endospores C) organelles D) toxins E) nuclei

18) The contradictory results obtained by different scientists apparently doing the same experiments in investigating spontaneous generation A) show that doing experiments once should be enough to prove something. B) show the importance of exactly duplicating experimental conditions. C) led to further experiments that ultimately proved spontaneous generation. D) could not be explained by anyone involved in the work. E) led to the development and production of swan-necked flasks.

19) If Pasteur had done his experiments investigating spontaneous generation in a horse stable, A) the results would probably have supported the idea of spontaneous generation. B) the results would probably not have supported the idea of spontaneous generation. C) the results would probably been the same as those obtained in a laboratory. D) the results would probablyhave supported the idea of spontaneous biogenesis. E) it would probably have taken several years to obtain any results.

20)

Cellulose is a major component of plants and is only directly digested by

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A) carnivores. B) termites. C) herbivores. D) microorganisms. E) birds.

21)

Plants are dependent on microorganisms for A) providing oxygen in a usable form. B) providing water and carbon dioxide. C) changing atmospheric nitrogen to a usable form. D) providing simplecarbohydrates in a usable form. E) providing simple and complex proteins.

22)

Microorganisms are useful for all of the following EXCEPT A) causing disease. B) curing/treating disease. C) preparing food. D) cleaning up pollutants. E) scientific research.

23) Bacteria have been used to help produce or modify all of the following food products EXCEPT A) cheeses. B) beer and wine. C) pickled products. D) bread. E) peanuts.

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24)

Microorganisms areinvolved in all of the following EXCEPT

A) production of medicinal products. B) food production. C) pollution cleanup. D) converting nitrogen to a form useful to plants. E) There are no exceptions here. There are microorganisms that participate in each of these activities.

25)

Bioremediation refers to A) rehabilitating wayward pathogenic bacteria. B) using bacteria to clean up environmental pollutants. C) development of new vaccines. D) monitoring newly discovered disease organisms. E) destroying organisms causing infectious diseases.

26)

Which of the following about the Golden Age of Medical Microbiology is FALSE? A) It started with the development of the first microscopes. B) It occurred during the late 1800s to the early 1900s. C) It is a time when the knowledge of bacteria and work with them expanded. D) It was the time when people realized that diseases could be caused by invisible

agents. E) It was a time when several major advances were made in microbiology.

27) Which of the following statements about newly emerging or reemerging diseases is FALSE? A) They may be caused by changing lifestyles. B) Examples include hepatitis C, Ebola disease and COVID-19. C) They may result from a breakdown in sanitation and social order. D) They are all caused by drug-resistant pathogens. E) They may result when microbes evolve and develop new characteristics.

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28)

Lyme disease is an example of a disease that is due to A) increased interaction between humans and tick-carrying animals. B) failure to effectively vaccinate children. C) a mutation in the human genome. D) climate change leading to a significantly greater mosquito population. E) an increase in the number of people travelling to Asia and Africa.

29)

The outbreak of measles within the last few years is due to A) mutation of the measles virus. B) change in the environment and climate. C) a decline in vaccination of children in the previous years. D) increase in sensitivity of detection techniques. E) emergence of novel measles viruses.

30)

Which of the statements regarding smallpox is TRUE?

A) Smallpox has been eliminated as a naturally occurring infection in human beings through vaccination. B) Smallpox still occasionally occurs in developing countries though failure to vaccinate everyone. C) Smallpox outbreaks sometimes occur in chimpanzee populations but seldom kills the animals. D) Smallpox outbreaks sometimes occur in chimpanzee populations and kills all the animals affected. E) Smallpox continues to be a common, naturally occurring infection in human beings.

31)

Smallpox

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A) has occurred in a few countries since 1977. B) has little potential as a weapon of bioterrorism. C) has not occurredanywhere in the word since 1977. D) very seldom kills people, but does scar them. E) is an emerging infectious disease.

32)

Ulcers, previously thought to be caused by stress, are in fact often caused by A) a bacterial infection. B) an insufficient diet. C) a genetic mutation. D) a fungal pathogen. E) a viral infection.

33)

Bacteria are useful to study because

A) they produce protein in a simpler manner than more complex organisms. B) they have the same fundamental metabolic and genetic properties as higher organisms. C) they produce energy in a simpler manner than more complex organisms. D) they both synthesize and are resistant to all known antibiotics. E) they produce peptidoglycan in a simpler manner than more complex organisms.

34)

Which of the following regarding normal microbiota is TRUE? A) Normal microbiota are only found in the lungs or digestive tract. B) Normal microbiota protect us from disease by competing with pathogenicbacteria. C) Normal microbiota are only found on small select parts of the human body. D) Normal microbiota typically cause disease when growing in or on our bodies. E) Normal microbiota play little or no role in the general health of humans.

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35)

Bacteria are present on the body A) only during disease-causing infections. B) at all times. C) only in certain areas. D) only after intense exercise. E) only after using public transport.

36)

Bacteria are good research models because they A) vary in size from microscopic to macroscopic. B) share manyproperties with more complex organisms. C) can be assembled into complex multicellular organisms. D) have similarly complicated growth requirements. E) develop the same diseases as humans and animals.

37)

Select the FALSE statement regarding bacteria. A) They are usually rod, sphere, or spiral in shape. B) They reproduce by binary fission. C) They contain a peptidoglycan cell wall. D) They are found as single cells. E) They are never photosynthetic.

38)

Which is usually NOT true of archaea? A) They move using flagella. B) They reproduce by mitosis. C) They contain rigid cell walls. D) They are found as single cells. E) They are prokaryotes.

39)

All of the statements regarding archaea are true EXCEPT

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A) they contain peptidoglycan in their cell walls. B) they reproduce by binary fission. C) they contain a rigid cell wall. D) they are found as single cells. E) they often grow in extreme environments.

40)

An extreme environment in which archaea have been found is A) lakes and oceans. B) boiling hot springs. C) marshes and swamps. D) refrigerators. E) animal digestive tracts.

41) The cell types that lack a membrane-bound nucleus and have rigid cell walls of peptidoglycan are A) eukaryotes. B) fungi. C) bacteria. D) archaea. E) protozoa.

42)

The prokaryotic domain includes A) bacteria AND fungi. B) archaea AND viruses. C) fungi AND bacteria. D) bacteria, archaea, AND fungi. E) bacteria AND archaea.

43)

Select the TRUE statement(s) regardingeukaryotes.

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A) Eukaryotes are all multicellular organisms AND have a membrane around the DNA. B) Eukaryotes have a more complex internal structure than archaea or bacteria. C) Eukaryotes have a simpler internal structure than archaea or bacteria AND have a membrane around the DNA. D) Eukaryotes have a membrane around the DNA. E) Eukaryotes have a more complex internal structure than archaea or bacteria AND have a membrane around the DNA.

44)

Which group(s) below contain single-celled and multicellular organisms? A) Algae AND bacteria B) Fungi AND archaea C) Protozoa AND bacteria D) Algae AND fungi E) Fungi AND protozoa

45)

All living organisms A) may be classified in four domains. B) may be classified in three domains. C) probably do not have a common ancestor. D) have never shared genes between domains. E) are capable of causing disease.

46)

The system by which organisms are named is referred to as A) systematics. B) naming. C) nomenclature. D) binomialism. E) bioinformatics.

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47)

The scientific name of an organism includes its A) family and genus. B) first name and last name. C) genus and species. D) domain and genus. E) domain and species.

48)

Which are the correctly written scientific name? A) Staphylococcus aureus B) Staphylococcus a. C) St. aureus D) Staph

49)

Which of these applies to the term strain? A) E. coli 0157:H7 B) E. coli C) Minor variation of a species D) Major variation of a species E) E. coli 0157:H7 AND minor variation of a species

50)

Select the statement that is TRUE regarding viroids. A) They are naked (lacking a protein shell) pieces of RNA. B) They are naked (lacking a protein shell) pieces of DNA. C) They are known to cause neurodegenerative diseases in animals. D) They are composed of protein encasing a DNA genome. E) They are composed of both RNA and DNA within a lipid coat.

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51)

Outside of a host cell, viruses are A) carrying out a few biochemical reactions. B) synthesizing proteins necessary for entry into the host. C) inert, and not capable of replication. D) constructing a membrane known as an envelope. E) capable of a few replication cycles.

52)

Viruses may only be grown A) in sterile growth media. B) in living cells. C) at body temperature. D) in darkness. E) in liquid broths.

53)

Viruses are in the domain(s) A) viridae. B) eukarya. C) archaeaAND bacteria. D) bacteria AND viridae. E) None of the answer choices is correct.

54)

Which if the following is TRUE regarding viruses? A) They are obligate intracellular parasites. B) They are single-celled organisms. C) They are composed of only proteins. D) They belong tothe domain Archaea. E) They containonly of DNA or RNA.

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55)

What do viruses, viroids, and prions all have in common? A) They contain only RNA and protein. B) They are acellular agents of disease. C) They contain only DNA or protein. D) They infect only animals. E) They cause neurodegenerative diseases.

56)

Viruses and viroids are A) capable of independent reproduction. B) obligate intracellular parasites. C) members of the domain Bacteria. D) larger than most bacteria in size. E) agents that cause disease in animals.

57)

Which is TRUE about prions? A) They are only composed of RNA. B) They are only composed of DNA. C) They are only composed of protein. D) They cause diseases in plants. E) They are only composed of RNA and DNA.

58) A new organism was found that was unicellular and 1 cm long. The "large" size of this organism alone would A) mean that it couldnot be a bacterium. B) mean that it must be a protozoan. C) not be useful for identifying it. D) mean that it belongs in the domain Eukarya. E) suggest that it is a virus.

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59) Although it is said that the twentieth century was the Age of Physics, it is predicted that the twenty-first century will be the age of A) chemistry. B) computers. C) microbial biodiversity. D) mathematics. E) psychology.

60) HIV/AIDS can be categorized as a new or emerging infectious disease. By putting it into this category, we areindicating that A) this infection hasn't been observed in the human population prior to recent (within the last 50 years) outbreaks. B) this disease hasbeen in susceptible populations for centuries, but has only recently achievedinfection levels that became detectable. C) the infectiousagent is still evolving and changing, unlike with older, moreestablisheddiseases such as plague or polio. D) the disease hasalways been in susceptible populations and causing disease, but we lacked thetechnology to detect it. E) this infection hasn't been observed in the human population prior to recent (within the last 5 years) outbreaks.

61) An illness outbreak occurs in New York City birds in the late 1990s. After an investigation, the Centers for Disease Control (CDC) determine that the agent causing theis the West Nile virus. Outbreaks of this illness have been observed in several other countries in Asia and the Middle East across the last 50 years, but not in the United States. With this information, what would be the best categorization of this infectious agent/disease?

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A) This isa reemerging infection. It is been around for a long time, and it is reappearing in a susceptible population again. B) This isa nosocomial (hospital-acquired)infection. It is transmitted from animals to human beings in urban environments. C) This is an emerging infection. It hasn't been around that long, and it has made a jump across continents into a new susceptible population. D) This is an unimportant infection thatnot a concern to human beings because it occurs in birds, so there is no need to classify it. E) This is a chronic infection. It has been around for many years, and it has made a jump across continents into a new susceptible population.

62)

Why are we concerned at all with monitoring emerging/reemerging diseases?

A) These representgrowing threats to human health that will require new scientific research andresources to effectively combat. B) Because globalization leads to more chances for spread of illnesses into new areas and populations. Monitoring these illnesses will help us to protect people. C) Because the speed of travel has increased, so it is far more likely that a serious pathogen can spread rapidly across the globe. Monitoring these illnesses will help us protect populations. D) All of the answer choices are correct. E) None of the answer choices is correct.

63) A microbiologist obtained two pure isolated biological samples: one is a virus, and one is a viroid. The labels came off the samples during a move from one lab to the next, however. The scientist felt she could distinguish between the two samples by analyzing for the presence of a single type of molecule. Whatwould she be looking for to differentiate between the two? A) DNA B) Protein C) Lipid D) RNA E) Carbohydrate

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64) A scientist has two samples—the first is a prion, while the second is a viroid. However, the samples are in unlabeled tubes.The scientistwants to run a simple analysis to determine which tube contains the prionand which one contains the viroid. What type of molecule would she look for to do this? A) Lipids B) DNA C) Protein D) Polysaccharides E) Peptidoglycan

65) A scientist discovers a new species near coral reefs in Australia. He finds that this singlecelled species is photosynthetic (using sunlight for energy), has a rigid cell wall structure with no peptidoglycan, uses a flagellum for motion, and contains a variety of internal structures that are membrane-bound. Given this information, this new species is most likely a(n) ______ cell in the ______ domain. A) bacterial; Eukarya B) fungal; Prokarya C) viral; Archaea D) algal; Eukarya E) protozoan; Bacteria

66) Scientists recently cloned Louis Pasteur and put him to work in a modern lab. He immediately developed a topical gel (used externally) that breaks down proteins. Since he hasn't been around for some time, he's unsure what the best application for his invention might be. Help him out. What pathogenic agent would this gel be most effective and safe at eliminating? A) Viroids on the surface of agricultural plant tissues. B) Prions inside the central nervous system of cows. C) Viruses on the surface of the skin. D) Bacteria in the intestines of human beings. E) The fungus that causes infections under people's toenails.

67)

Select the TRUE statement regarding viruses.

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A) Most viruses are smaller than bacteria but bigger than mitochondria. B) Viruses may be unicellular or multicellular. C) Viruses contain both DNA and RNA. D) Viruses always cause death of the host cells they infect. E) Virus are considered living because they contain nucleic acid.

68) You are examining a pea plant that is showing signs of disease—brown leaves and no pea pods. You isolate an agent from the plant that only contains RNA and protein. This is a(n) ______. A) viroid B) virus C) bacterium D) fungus E) protozoan

69)

Which terms refer to bacterial morphology? A) Bacillus AND polyhedral B) Coccus AND polyhedral C) Coccus AND Bacillus D) Polyhedral, coccus, AND Bacillus E) Coccus AND squarish

70) What was the significance of the shape of the flasks used by Pasteur in his experiments proving biogenesis?

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A) The flask shape allowed Pasteur to use less broth, so the experiments were cheaper and could be repeated more often. B) The swan neck of the flasks allowed “vital force” to enter them but prevented bacteria from falling into the broth. C) Swan-necked flasks have an opening too small for entry of microbes, while conical flasks have a wide neck that allows microbial entry. D) Pasteur could place gel in the bend of the swan-necked flask, trapping any entering microbes. E) There is no significance; Pasteur simply used any flasks available in his laboratory, in this case swan-necked.

71) A patient’s throat swab yields organisms that appear as long chains of round cells under light microscope. Given this information, it is possible that the organism is: A) Streptococcus pyogenes B) Staphylococcus aureus C) Bacillus species D) A virus E) Streptococcus pyogenes OR Staphylococcus aureus

72)

Which statement about normal microbiota is TRUE?

A) The body carries 10 times as many microbial cells as human cells. B) Normal microbiota is restricted to the gut and only plays a role in digestion and vitamin synthesis. C) The microbiome includes members of a microbial community and the genetic makeup of that community. D) The majority of microbes in a microbiome can be identified by culturing them in a laboratory. E) Bacterial species associated with gum disease also always cause Alzheimer’s disease.

73)

Which of the following bacterial pairs is LEAST related?

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A) Escherichia coli K AND Escherichia coli B12 B) Bacillus subtilis AND Bacillus cereus C) Vibrio cholerae O1 AND Vibrio cholerae O139 D) Escherichia coli O157:H7 AND E. coli O157:H4 E) Streptococcus pneumoniae AND Mycoplasma pneumoniae

74) Consider the Venn diagram pertaining to the three domains, and select the CORRECT characterization. Remember that characteristics shared by two or more items are found in the circle overlaps.

A) Prokaryote AND peptidoglycan - B B) Eukaryote AND multicellular - G C) Prokaryote AND multicellular - D D) Prokaryote AND nucleus - E E) Prokaryote - F

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75) Consider the Venn diagram pertaining to prokaryotes, eukaryotes and acellular agents, and select the INCORRECT classification. Remember that in a Venn diagram, common characterisitcs are found in the circle overlaps.

A) Peptidoglycan, 70S ribosomes and nucleoid - A B) Cytoplasm, ribosomes and DNA - B C) DNA or RNA, lipid and protein - G D) Ribosomes, cytoplasm and nucleic acid - E E) Mitochondria, Golgi and chloroplasts - C

SECTION BREAK. Answer all the part questions. 76) A scientist isolates a microbe from a contaminated water source. She thinks that the organism might be a new bacteria that is capable of surviving in the presence of lead, which is a heavy metal. She makes tubes of nutrient medium (supports microbial growth) containing either no lead, 0.1 mg lead, 0.25 mg lead, 0.5 mg of lead, or 1 mg of lead. She inoculates each tube with the 10 x 103 cells of the new organism and then incubates the tubes at 37oC. After 48 hours, she examines the tubes and finds that there is no growth in any of them. However, she finds that the organism grew well in medium that did not contain any lead. She decides to repeat the experiment using lower concentrations of lead than those she used initially.

76.1)

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Select which of the following is the hypothesisbeing tested by the scientist.

A) The newly isolated microbe can grow in the presence of lead. B) The newly isolated microbe is a bacteria. C) Lead can be placed into tubes of growth medium. D) Bacteria must be incubated for 72 hours before they grow. E) Lead is a good nutrient for all bacterial growth.

76.2)

Identify the control step in the scenario described.

A) Inoculating the test microbe into nutrient medium containing a different heavy metal. B) Isolating the microbe from a contaminated water source. C) Inoculating the test microbe into nutrient medium lacking lead. D) Inoculating the test microbe into medium containing lower levels of lead than used initally. E) Inoculating the test microbe into contaminated water containing high levels of lead.

76.3)

What conclusion can the scientist in this scenario make from her results?

A) The test bacteria take more than 48 hours to grow in the laboratory when incubated at 37 oC. B) All contaminated water contains high levels of lead and other heavy metals. C) The test organism was killed by the levels of lead tested. D) All experiments should be repeated three times or more. E) Lead-contaminated water never contains any living organisms.

77) Janus is a keen baseball player at the high school where you are employed as a nurse. He comes to your office and shows you an injury to his knee which he got by sliding into home base, scoring a game-winning run. His knee has araw patch where the skin has been scraped off, and the area around the wound is swollen.Janus tells you that he washed his knee with soap and water to remove any germs, and then put a bandage onit, but it is very painful and red.

77.1) You explain to Janus that he may have an infection in his wound, possibly caused by the organism Staphylococcus epidermidis. You tell him that the genus name of the organism indicates that Version 1

A) the cells are found in the digestive tract. B) the cells are round and grow in clusters. C) the organism is a pathogen. D) the organism is normal microbiota. E) the cells have a golden color.

77.2) Janus tells you he knows that yeast cells are also round. He asks how scientists can tell the difference between yeasts and bacteria. Select the choice that best answers his question. A) Bacteria are microscopic. B) Bacteria are photosynthetic. C) Bacteria are unicellular. D) Bacteria contain peptidoglycan. E) Bacteria can be pathogenic.

77.3) Janus asks you if there is something he can use to kill any bacteria in his wound without affecting any of his own body cells. You tell him that some antibiotics kill bacteria by targeting _____ , a compound unique to bacteria. A) protein B) nuclear membrane C) flagella D) peptidoglycan E) chitin

77.4) Janus' knee infection should be considered an emerging infectious disease, and you should report it to the Centers of disease Control (CDC). ⊚ ⊚

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true false

78) Sandy has been taking an antibiotic for a urinary tract infection (UTI). Although the signs and symptoms of Sandy's UTIresolved after a few days of taking the medication, she complains to you that she has been having watery diarrheafor the last two days, and she wonders whether the antibiotic is affecting her digestive tract. You take the opportunity to give her information about her normal microbiota.

78.1) You explain to Sandy that her body carries an enormous population of microorganisms, collectively called the normal microbiota. You tell her that this population has a vital role in maintaining her health. Select the FALSE statement regarding the role of the normal microbiota.  A) Normal microbiotaprevent disease by competing with pathogenic microbes. <!-Markup Copied from Habitat--> B) Normal microbiotahelp to degrade foods that the body otherwise could not digest.  C) Normal microbiotasynthesize vitamins that the body cannot produce.  D) Normal microbiotaproduce insulin for controlling blood sugar levels. E) Normal microbiotalikely affects the tendency to lose or gain weight.

78.2) You are concerned that Sandy may have a Clostridioides difficile infection (CDI). When normal microbiota is disturbed, organisms such as C. difficile may thrive. What caused the disturbance in Sandy's normal microbiota in this case? A) The bacteria causing Sandy's urinary tract infection. B) The antibiotics Sandy was taking to treat her UTI. C) Sandy's presence in the hospital. D) Sandy's watery diarrhea. E) Dehydration caused by Sandy's watery diarrhea.

78.3)

Digestive tract microbiome plays no role in maintaining a person's health.

⊚ ⊚

true false

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79) Five patients were admitted into the hospital, each one suffering of a different illness. Tests were carried out on each patient to identify the pathogens causing their illnesses. The chemical composition of the pathogens was established and is shown in Table 1: Table 1. Chemical composition of isolated pathogens. Protein

Lipid

DNA

RNA

Patient #1

Patient #2

Patient #3

Patient #4

Patient #5

Note: (+) indicates presence; (-) indicates absence

79.1)

What type of pathogen could be causing the disease in patient #1?

A) A virus B) A bacterium C) A fungus D) A prion E) A yeast

79.2)

Which patient(s) is/are being infected by an acellular infectious agent?

A) Patients 1, 3, and 4 B) Patients 1, 2, 3 and 4 C) Patients 2 and 3 D) Patients 1, 2, 3 and 5 E) Patients 2, 3, 4 and 5

79.3)

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What treatment(s) would likely be the most appropriate to treat patient #2?

A) Antiviral drug B) Antibiotic, antifungal or antiprotozoan drug C) Antifungal drug D) Antibiotic AND antiviral drug E) Antiprotozoan drug

79.4)

Which patient(s) is/are affected by a pathogen that specifically affects the brain?

A) Patient #1 ANDPatient #4 B) Patient #2 ANDPatient #3 C) Patient #3 D) Patient #1 AND Patient #3 E) Patient #4

79.5)

Which patient(s) is/are infected by a pathogen that divides by binary fission?

A) Patient #2 B) Patient #2 AND Patient #5 C) Patient #2 AND Patient #4 D) Patient #4 E) Patient #5

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Answer Key Test name: Chap 01_10e 1) FALSE 2) FALSE 3) FALSE 4) FALSE 5) TRUE 6) FALSE 7) TRUE 8) FALSE 9) FALSE 10) FALSE 11) FALSE 12) B 13) C 14) C 15) B 16) B 17) B 18) B 19) A 20) D 21) C 22) A 23) E 24) E 25) B 26) A Version 1

27) D 28) A 29) C 30) A 31) C 32) A 33) B 34) B 35) B 36) B 37) E 38) B 39) A 40) B 41) C 42) E 43) E 44) D 45) B 46) C 47) C 48) A 49) E 50) A 51) C 52) B 53) E 54) A 55) B 56) B Version 1

57) C 58) C 59) C 60) A 61) C 62) D 63) B 64) C 65) D 66) C 67) A 68) B 69) C 70) B 71) A 72) C 73) E 74) B 75) D 76) Section Break 76.1) A 76.2) C 76.3) C 77) Section Break 77.1) B 77.2) D 77.3) D 77.4) FALSE 78) Section Break 78.1) D Version 1

78.2) B 78.3) FALSE 79) Section Break 79.1) A 79.2) A 79.3) B 79.4) E 79.5) B

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CHAPTER 2 TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) If you placed a DNA molecule in a vertical orientation, then from top to bottom, the two parallel strands are both orientedin the same, 5ʹ to 3ʹ, direction. ⊚ ⊚

RNA is a long double-stranded helix containing ribose and uracil. ⊚ ⊚

true false

Lipids, like nucleic acids and proteins, are made of chains of similar subunits. ⊚ ⊚

true false

Steroids are simple lipids. ⊚ ⊚

true false

5) Water-soluble substances easily pass through the phospholipid bilayer of a cell membrane. ⊚ true ⊚ false

DNA is always double-stranded, but RNA is always single-stranded. ⊚ ⊚

true false

Lipids are polar, hydrophilic molecules.

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⊚ ⊚

true false

Simple lipids contain carbon, hydrogen, and oxygen in a 1:2:1 ratio. ⊚ ⊚

true false

Phospholipids are polar molecules. ⊚ true ⊚ false

10)

Unsaturated fats have lower melting points than saturated fats. ⊚ ⊚

true false

CHECK ALL THE APPLY. Choose all options that best completes the statement or answers the question. 11) The atomic number for an atom of a specific element is equal to 2-12-2013 A) the number of protons plus electrons in a single atom of that element. B) the number of electrons plus neutrons in a single atom of that element. C) the number of protons plus neutrons in a single atom of that element. D) the position of an atom in the atomic table. E) the position of an ion on the periodic table.

MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 12) In addition to investigations with bacteria that led to Pasteur being considered the Father of Microbiology, he also

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A) found that some molecules can exist as stereoisomersANDcreated aspartame. B) created aspartame ANDseparated organic acids using a microscope. C) found that some molecules can exist as stereoisomers AND separated organic acids using a microscope. D) separated organic acids using a microscope ANDdiscovered polarized light. E) discovered polarized light AND found that some molecules can exist as stereoisomers.

13)

The negatively charged component of the atom is the A) proton. B) electron. C) neutron. D) nucleus. E) valence.

14)

The part of the atom that is most involved in chemical reactivity is the A) proton. B) neutron. C) electron. D) nucleus. E) ion.

15)

Which of the following is TRUE regarding electrons? A) They are found in the area outside the nucleus known as the cloud. B) They may gain energy but do notlose energy. C) They cannot move from one shell to another within the cloud. D) They are located farthest from the nucleus and have the leastenergy. E) They are positively charged particles in an atom.

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16)

Sharing of electrons between two atoms forms a(n) A) hydrogen bond. B) ionic bond. C) covalence bond. D) atomic bond. E) covalent bond.

17)

If electrons are gained or lost when a bond is formed, that bond is a(n) ______ bond. A) ionic B) covalent C) hydrogen D) nonpolar E) intermediate

18)

Charged atoms are called A) ions. B) neutrons. C) molecules. D) polymers. E) atoms.

19)

Which statement regarding water is TRUE? A) Water is a polar molecule. B) Water is referred to as a universal solvent. C) Water makes up over 70% of an organism. D) Water is often a product or reactant in chemical reactions. E) All of the answer choices are correct.

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20)

Which statement regarding pH is CORRECT? A) pH is a measure of the hydrogen ion concentration in a solution. B) pH is measured using a scale from 5 to 8. C) pH is measured using a linear (not logarithmic)scale. D) pH is an abbreviation for "power of helium." E) pH reflects the tendency of a solution to donate or accept electrons.

21)

The subunits (building blocks) of proteins are A) nucleotides. B) phospholipids. C) amino acids. D) carbohydrates. E) monosaccharides.

22)

If the side chains of amino acids contain carboxyl (-COOH) groups, they

A) contribute a positive charge to the amino acid at pH 10 AND are considered acidic amino acids. B) contribute a negative charge to the amino acid at pH 10 AND are considered nucleic acids. C) contribute a positive charge tothe amino acid at pH 10 AND are considered nucleic acids. D) contribute a negative charge to the amino acid at pH 10 AND are considered acidic amino acids. E) contribute a negative charge to the amino acid at pH 10 AND are considered acidic monosaccharides.

23)

Amino acids that contain many methyl (-CH

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3) groups

A) are considered hydrophilic. B) are nonpolar. C) carry a positive charge. D) carry a negative charge. E) are considered hydrophilic AND carry a positive charge.

24)

D-amino acids are associated with A) radioactive isotopes. B) bacterial cell walls. C) plant proteins. D) human proteins. E) all proteins.

25)

The most important feature of a protein is its A) secondary structure. B) side group. C) shape. D) electric charge. E) size.

26)

Alpha helices and beta pleated sheets form a protein's A) primary structure. B) secondary structure. C) tertiary structure. D) quaternary structure. E) multi-structure.

27)

Select the CORRECT statement regarding acidic or basic amino acids.

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A) They are insoluble in water. B) They are readily soluble in water. C) They areunable to form ions. D) They are considered hydrophobic. E) They are unable to form peptide bonds.

28)

The N terminal in a protein is A) the end characterized by a free carboxyl group. B) the end characterized by a free amino group. C) typically found in the middle of a protein. D) the part of a protein that is bound to another protein. E) indicatedwith an "R".

29)

Select the FALSE statement regarding protein denaturation. A) Denaturation can occur due to certain chemicals. B) Denaturation can occur due to pH changes. C) Denaturation can occur due to high temperature. D) Denaturation may cause the protein to no longer function. E) Denaturationcannot be reversed.

30)

Select the FALSE statement regarding carbohydrates. A) They may be part of the structure of bacteria. B) They may serve as a source of food. C) They contain carbon, hydrogen, and oxygen in a 1:2:1 ratio. D) They may be bonded to proteins to form glycoproteins. E) Cholesterol and ergosterol are examples of carbohydrates.

31)

Select the CORRECT statement regarding carbohydrates.

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A) They form only ring structures. B) They form only linear structures. C) They may interconvert between ring and linear structures. D) They contain both ring and linear portions within the same molecule. E) They are all structural isomers of each other.

32)

Structural isomers

A) contain the same number of atoms/elements, butin different arrangements AND may be referred to as the -D and -P forms. B) are exemplified by glucose and galactose AND are formed by different arrangements of the -COOH groups C) contain the samenumber of atoms/elements, butin different arrangements AND areexemplified by glucose and galactose. D) are formed by different arrangements of the -COOH groups AND may be referred to as the -D and -L forms. E) may be referred to as the -D and -Pforms AND are exemplified by glucose and fructose.

33)

What type of bond holds one strand of DNA to the complementary strand of DNA? A) Covalent B) Hydrogen C) Disulfide D) Ionic E) Peptide

34)

How many carbon atoms do the sugars found in nucleic acids contain?

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A) 3 carbon atoms. B) 5 carbon atoms. C) 7 carbon atoms. D) 9 carbon atoms. E) either 5 or 7 carbon atoms.

35)

Which of the following are found in RNA but not in DNA? A) Adenine AND ribose B) Ribose AND thymine C) Ribose AND uracil D) Thymine AND uracil E) UracilAND deoxyribose

36)

Which base pairing example is INCORRECT? A) A:T B) G:C C) G:T D) A:U E) A:T, G:C, AND A:U

37)

The components of fats are fatty acids and A) amino acids. B) nucleotides. C) phosphate. D) glycerol. E) cholesterol.

38)

Select the CORRECT statement regardingsaturated fats and unsaturated fats.

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A) They have approximately the same melting temperature as each other. B) Saturated fats have a lower melting temperature than unsaturated fats. C) Unsaturated fats have a lower melting temperature than saturated fats. D) Unsaturated fats have a higher melting temperature than saturated fats. E) Saturated fats are more liquid at room temperature than unsaturated fats.

39)

Which is the positively charged component of the atom? A) Electron B) Neutron C) Proton D) Cation E) Anion

40)

Which is the uncharged component of the atom? A) Electron B) Proton C) Neutron D) Proline E) Neulon

41)

What determines the chemical and physical properties of an atom of an element? A) Atomic number B) Neutrons C) Atomic weight D) Electrons E) Atomic size

42)

Why does the atom have no charge overall?

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A) The number of protons in the atom equals the number of neutrons. B) The number of electrons in the atom equals the number of neutrons. C) Neutrons in the atom neutralize all the other charges. D) The number of protons in the atom equals the number of electrons. E) The number of protons in the atom exceeds the number of electrons.

43)

The mass number of an atom is equal to A) the number of electrons. B) the number of electrons and neutrons. C) the number of neutrons and protons. D) the number of protons. E) the number of electron shells.

44)

If electrons are shared unequally, a(n) ______ bond is formed. A) weak B) polar C) nonpolar D) ionic E) hydrogen

45)

Atoms that gain electrons become A) positively charged. B) negatively charged. C) neutral. D) lighter. E) elements.

46)

Which of these bonds are weak individually but are much stronger as a group?

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A) Covalent AND hydrogen B) Ionic AND covalent C) Neutron AND ionic D) Hydrogen AND neutron E) Ionic AND hydrogen

47)

The most important molecule(s) in the world is (are) _____. A) water B) proteins C) carbohydrates D) nucleic acids E) nitrogen

48)

The components of adenosine triphosphate are A) adenosine, deoxyribose, and three phosphates. B) adenosine, ribose, and three phosphates. C) a pyrimidine base, ribose, and three phosphates. D) a purine base, deoxyribose, and two phosphates. E) a pyrimidine base, deoxyribose, and three phosphates.

49)

How many different amino acids are there to choose from when assembling a protein? A) 5 B) 10 C) 20 D) 25 E) 64

50)

L-amino acids occur in proteins and are designated

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A) unnatural. B) left-handed. C) rare. D) right-handed. E) non-biological.

51)

Amino acids in proteins are linked to one another by peptide bonds between the A) methyl group of one amino acid and a side group of another amino acid. B) carbon atoms of two adjacent amino acids. C) carboxyl group of one amino acid and the amino group of another. D) nitrogen atom and carboxyl ion. E) phosphate group and nitrogenous base.

52)

The primary structure of a protein refers to A) the helical folding of a protein. B) the sequence of amino acids. C) two or more polypeptides linked to one another. D) the initial folding of a protein. E) the beta-pleated sheets in a protein.

53)

Side chains are important to proteins because they

A) help determine protein shape AND are a source of energy for hydration reactions in the cell. B) help determine the degree of solubility of the protein in water. C) are a source of energy for hydration reactions in the cell. D) form the peptide bonds that link amino acids to one another. E) help determine protein shape AND help determine the solubility of the protein in water.

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54)

Which statement(s) regarding a protein is/are CORRECT?

A) A protein can form any number of equally functional shapes. B) A protein may need help from chaperonesto assume the correct shape. C) A protein consists of a chain of hydroxyl acids AND is always polar. D) A protein is always polar AND may need help from chaperones to assume the correct shape. E) A protein assumes any number of equally functional shapes AND is always polar.

55)

Weak bonds are important for the ______ structure of proteins. A) primary AND secondary B) primary, secondary, AND tertiary C) secondary, tertiary, AND quaternary D) primary, tertiary, ANDquaternary E) quarternary

56)

Which statements about proteins are TRUE?

A) They are involved in almost every important function performed by a cell AND are characterized by a 1:3:1ratio of carbon to hydrogen to oxygen. B) They make upmore than 50% of the dry weight of a cell AND are composed of a chain of nucleotides. C) They are involved in almost every important function performed by a cell AND make up more than 50% of the dry weight of a cell. D) They are composed of a chain of amino acids AND are characterized by a 1:3:1 ratio of carbon to hydrogen and oxygen. E) They are characterized by a 1:2:1 ratio of carbon to hydrogen to oxygen AND are composed of a chain of nucleotides.

57)

The carbohydrate(s) found in nucleic acids is (are)

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A) ribose OR deoxyribose. B) ribose OR glucose. C) glucose OR galactose. D) galactose OR deoxyribose. E) deoxyriboseonly.

58)

The -OH group in a carbohydrate

A) may be found above or below the plane of the ring. B) is involved in the formation of stereoisomers. C) is involved when linking monosaccharides together. D) is involved in the formation of stereoisomers ANDmay be found above or below the plane of the ring. E) All of the answer choices are correct.

59)

Dehydration reactions are involved in A) the formation of polypeptides AND the formation of monosaccharides. B) the formation of polysaccharides AND the formation of nucleotides. C) the formation of polypeptides AND the formation of polysaccharides. D) the formation of monosaccharides AND the formation of amino acids. E) the formation of polypeptides AND the formation of nucleotides.

60)

Which statement is true of nucleotides? A) They are the basic subunits of DNA. B) There are 20 naturally occurring nucleotides. C) They are joined together by peptide bonds. D) They are double-stranded. E) All of the answer choices are correct.

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61)

The purines of DNA are A) adenine and guanine. B) thymine and adenine. C) serine and threonine. D) thymine and uracil. E) thymine, adenine AND uracil.

62) To which end of the nucleic acid chain are more nucleotides added during DNA synthesis? A) 5 prime (5') end. B) C terminal. C) 3 prime (3') end. D) N terminal. E) -COOHterminal.

63)

The characteristic common to all lipids is their A) solubility in organic solvents AND hydrophilic nature. B) solubility in organic solvents AND hydrophobic nature. C) hydrophilic nature AND large size. D) large size AND solubility in water. E) hydrophobic nature AND solubility in water.

64)

Which is NOT true of lipids? A) They are a major structural element of all cell membranes. B) They control the movement of molecules into and out of a cell. C) They separate a cell from its environment. D) Examples include steroids and phospholipids. E) They are a homogeneous group of molecules.

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65) Microorganisms use hydrogen bonds to attach themselves to the surfaces that they live on. Many of them lose hold of the surface because of the weak nature of these bonds and end up dying or being washed away. Why don't microbes just use covalent bonds instead? A) Covalent bonds depend on completely giving up or completely accepting an electron to form the bond. This isn't possible for many microbes without dramatically altering their basic molecular composition. B) Covalent bonds typically require enzymes to form/break, whereas hydrogen bonds don't. If covalent bonds were used, it would require much more energy and molecules to be contributed from the cell. Hydrogen bonds don't have these requirements. C) Bacteria grow in very moist environments, where water is freely available. Water is a supply of hydrogen atoms, so it makes sense for the bacteria to simply use hydrogen bonds for attachment. D) Hydrogen bonds typically require enzymes to form/break, whereas covalent bonds don't. Microorganisms have more enzymes than any other type of cell, so it makes sense that they use hydrogen bonds rather than covalent bonds. E) None of the answer choices is correct.

66) A biologist determined the amounts of several amino acids in two separate samples of pure protein. His data showed that Protein A contained 7% leucine, 12% alanine, 4% histidine, 2% cysteine, and 5% glycine. Interestingly, Protein B had the same percentagesof the same amino acids. He concluded from this datathat Proteins A and B are the same protein. Based on this information and his conclusion, determine which of the following is the correct statement regarding his findings: A) He is correct; the proteinshave the same percentages of each amino acid, so they are identical protein molecules. B) He is incorrect; there is no informationaboutthe amino acids sequence (which dictates the overall structure of a protein), so the two proteins could be very different in shape. C) He is correct; although there is no information on the amino acid sequence in each protein, the order of the amino acids is irrelevant. It's only the total number of each molecule that is important to structure. D) He is incorrect; he hasn't accounted at all for the effects of pH on the composition of the protein and its effects on the individual amino acids. E) He is partly correct; the percentage of the listed amino acids is the same in each protein, but Protein A is hydrophobic and Protein B is hydrophilic.

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67) You are a biochemist working on a molecule found in a recently discovered bacteria. You determine that the molecule is composed of a chain of similar subunits and can thus conclude that the molecule is unlikely to be a A) lipid. B) nucleic acid. C) protein. D) carbohydrate. E) lipid or protein.

68)

Which of the following pairs is mismatched? A) RNA - ribose sugar. B) Dehydration synthesis - water removal. C) Sharing electrons - covalent bond. D) Carboxyl - CH 3 E) Lipids - hydrophobic.

69)

Please identify the CORRECT definition.

A) Molecules that contain carbon and hydrogen are called inorganic compounds. <!-Markup Copied from Habitat--> B) Electrolytes are salts that conduct electricity when they are dissolved in water. C) A compound is a molecule composed of two or more identical elements. D) Electrons in a polar covalent bond are shared equally. E) The starting components of a chemical reaction are called products.

70)

Which of the following is the correct order from most acidic to least acidic?

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A) Stomach acid, vinegar, unpolluted rainwater, blood, drain cleaner B) Drain cleaner, blood, unpolluted rainwater, vinegar, stomach acid C) Unpolluted rainwater, blood, vinegar, drain cleaner, stomach acid D) Stomach acid, drain cleaner, unpolluted rainwater, blood, vinegar E) Vinegar, blood, unpolluted rainwater, drain cleaner, stomach acid

71) You are working in a laboratory, making media for growing bacteria. The recipe you are following calls for the addition of TRIS buffer. You can't find any TRISin the lab, so you decide to leave it out of the medium. Select the FALSE statement regarding your decision. A) The medium will likely not be useable, because bacteria live within a narrow pH range, near pH 14.  B) Maintaining the correct pH is essential for cells, because crucial molecules such as enzymes may lose function in the incorrect pH. C) Buffers are added to solutions to stabilize the hydrogen ion concentration of that solution. D) The acidity of the medium without buffer may change dramatically as the bacteria grow. E) The medium will likely not be useable, because bacteria live within a narrow pH range, near neutral.

72)

Which of the following statements about enzymes is FALSE? A) Enzymes are composed of amino acids. B) Enzymes help break covalent bonds. C) Enzymes position reactants so covalent bonds form more easily. D) Enzymes are essential for maintaining life. E) Enzymes increase the temperature of a reaction.

73)

Enzymes are required to break which of the following bonds?

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A) Covalent B) Ionic C) Peptide D) Hydrostatic E) Polar

74)

Which of the following statements about nucleic acids is FALSE? A) They are the subunits of nucleotides. B) They may be single stranded or double stranded. C) Eukaryotic cells have both DNA and RNA. D) All living cells have nucleic acids. E) They are composed of nucleotides.

75)

Please select the FALSE statement regarding butyrate. A) Butyrate is consumed in plant material. B) Butyrate is a short-chain fatty acid. C) Butyrate is produced by gut bacteria. D) Butyrate is a degradation product of plant material. E) Butyrate may protect against colon cancer.

76)

Please select the FALSE statement regarding lipids.

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A) Short-chain fatty acids contain five or fewer carbon atoms and may reduce the risk of colon cancer. B) Butyrate is a long-chain fatty acid that is produced by gut bacteria when they degrade undigested plant material. C) Phospholipids resemble triglycerides but one fatty acid is replaced with a phosphate group. D) A wax is a long-chain fatty acid covalently bonded to a long-chain alcohol and is insoluble in water. E) Steroids differ in structure from lipids but are classified as such because they are insoluble in water.

77)

Which of the following best describes the structure of DNA?

A) A double helix consisting of antiparallel two sugar-phosphate backbones with nucleobases oriented towards the interior. B) A double helix consisting of two chains of nucleobases held together by bonds between with sugar-phosphate groups. C) A triple helix consisting of three chains of nucleobases held together by bonds between with sugar-phosphate groups. D) A double helix consisting of two parallel sugar-phosphate backbones with nucleobases oriented towards the interior. E) A double helix consisting of two sugar-phosphate backbones with nucleobases oriented towards the exterior.

78) Which of the following correctly describes the pairing and hydrogen bonding of nucleobases in DNA?

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A) Adenine pairs with thymine via two hydrogen bonds; cytosine pairs with guanine via three hydrogen bonds. B) Adenine pairs with thymine via three hydrogen bonds; cytosine pairs with guanine via two hydrogen bonds. C) Adenine pairs with thymine via three hydrogen bonds; cytosine pairs with guanine via three hydrogen bonds. D) Adenine pairs with thymine via two hydrogen bonds; cytosine pairs with guanine via two hydrogen bonds. E) Cytosine pairs with thymine via two hydrogen bonds; adenine pairs with guanine via three hydrogen bonds.

79) What functional group is at the 5' end of a DNA strand, and which is at the 3' end of a DNA strand? A) Phosphate group at the 5' end; hydroxyl group at the 3' end B) Phosphate group at the 3' end; hydroxyl group at the 5' end C) Phosphate group at the 5' end and the 3' end on one strand; hydroxyl group at the 5' end and the 3' end on the other strand D) Phosphate group at the 5' end; deoxyribose at the 3' end E) Adenine or thymine at the 5' end; cytosine or guanine at the 3' end

80) Why are electrons not considered when determining the mass of an atom?  A) Electrons are too light too contribute to the mass of an atom. B) Every atom has random numbers of electrons, so they must be ignored. C) Electrons are too far away from the atom nucleus to contribute to its weight. D) Neutrons cancel out the mass of the electrons, so they are discounted. E) Protons cancel out the mass of electrons, so they are discounted.

81)

Which of the statements about ions is TRUE?

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A) Anions are negatively charged atoms while cations are positively charged atoms. B) Anions are positively charged atoms while cations are negatively charged atoms. C) An anion is an atom that has gained an electron and a proton. D) Cations and anions both have an overall positive charge. E) The ion Mg 2+ has gained two electrons while the ion Na + has gained one electron.

82)

In a redox reaction,

A) the reactant that loses an electron is oxidised and the reactant that gains an electron is reduced. B) the reactant that loses an electron is reduced and the reactant that gains an electron is oxidised. C) the reactant that loses an electron is a oxidising-oxidising agent. D) the reactant that gains an electron is reduced and is an oxidising reagent. E) both the reducing agent and the oxidising agent gain electrons.

83)

Which list goes from heaviest to lightest? A) Compound, atom, proton, electron B) Electron, proton, atom, compound C) Electron, proton, atom, molecule D) Proton, molecule, atom, electron E) Atom, molecule, proton, neutron

84)

Please select the CORRECT choice regarding pH and hydrogen ion concentration.

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A) A pH of 4 is more acidic than a pH of 5 AND the pH 4 solution has an H + concentration of 1 x 10 -4 B) A pH of 4 is less acidic than a pH of 5 AND the pH 4 solution has an H + concentration of 1 x 10 -4 C) A pH of 4 is more basic than a pH of 5 AND the pH 4 solution has an H + concentration of 1 x 10 -4 D) A pH of 4 is more acidic than a pH of 5 AND the pH 5 solution has an H + concentration of 1 x 10 5 E) A pH of 4 is more acidic than a pH of 5 AND the pH 4 solution has an OH concentration of 1 x 10 -4

85)

Dehydration synthesis is involved in the synthesis of all of the following EXCEPT A) glucose. B) DNA and RNA. C) peptidoglycan. D) enzymes. E) triglycerides.

86)

When the pH of a solution changes from 9 to 2, the H

concentration

A) increases as the solution becomes more acidic. B) decreases as the solution becomes more acidic. C) increases as the solution becomes more basic. D) decreases as the solution becomes more basic. E) remains unchanged as the solution becomes more basic.

SECTION BREAK. Answer all the part questions. 87) Dan is a body builder. He decides that he is going to change his diet in an effort to increase his muscle mass. Dan tells you that he plans to eat vegetables and proteins but nofats or carbohydrates, because cells do not naturally contain these molecules and do not need them. You advise Dan that his new diet is not a good choice, and that he would do better to follow a well balanced diet that incorporates healthy amounts of proteins, fats AND carbohydrates.

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87.1) You tell Dan that while many of his cell components do indeed contain amino acids, carbohydrates and lipids are also essential for cells. Which of the following components contain both amino acids AND lipids? A) Cytoplasmic membrane B) Nucleic acids C) Enzymes D) Peptidoglycan E) Ribosomes

87.2) Dan tells you that he knows proteins are needed to build muscle mass but that he doesn't quite understand the role of proteins in a cell. He tells you five things he believes proteins are needed for in cell function, but he is mistaken on one of these. Which of the following statements regardingthe role of proteins in cells is INCORRECT? A) Proteins are involved in transporting molecules into or out of cells. B) Proteins are involved in movement of certain cells. C) Proteins provide structural support in cells (cytoskeleton). D) Proteins are a major component of starch. E) Proteins catalyze chemical reactions within cells.

87.3) Dan tells you that he believes that proteins are the primary source of energy for his cells because proteins are easily digested. You tell him that this is. ⊚ ⊚

true false

87.4) Dan asks you how his cells are able to use complex molecules such as proteins. You explain to him that proteins are macromolecules composed of ______ and that proteins can be broken down by ______, a type of reaction in which the addition of ______ breaks covalent bonds between subunits.

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A) water; hydrolysis; amino acids B) amino acid; hydrolysis; water C) monosaccharides; hydrolysis; water D) amino acids; dehydration synthesis; water E) monosaccharides; dehydration synthesis; water

87.5) Dan is confused about the reason you advise him that in fact a healthy diet includes fats. He tells you that all fats are bad fats. You correct him, telling him that lipids are essential for cells. Which of the following is NOT true of lipids? A) Lipids are an essential component of the cytoplasmic membrane. B) Cholesterol provides rigidity to eukaryote cell membranes. C) Lipids are composed of identical subunits. D) The most common simple lipids in nature are the triglycerides. E) Oils contain unsaturated fatty acids.

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88) With so much research being carried out onthe gut microbiome, interesting discoveries are frequently made. Now scientists at MIT and Harvard University have investigateda novel bacterial enzyme that may have therapeutic potential for treating a disease called CDI, caused by the bacterium Clostridioides difficile. C. difficile is found at part of the gastrointestinal microbiotaof many healthy people. However, if the bacterial populations in those people are disturbed (a situation called dysbiota), for example by taking antibiotics, the organism can causeCDI. The research team discovered that C. difficile and a number of other gut bacteria produces an enzyme called hydroxyl-L-proline dehydratase (HypD). The scientists had previously shown that this enzyme carries out an unusual reaction, breaking down hydroxyl-L-proline into a precursor of proline, one of the 20 naturally occurring amino acids. In bacteria like C. difficile, proline can then be used to generate ATP through a process called amino acid fermentation. In other words, the microbes use HypD to help them grow. Now, using a method called X-ray crytallography, the team has been able to identify the active site on HypD where the chemical reaction takes place. Their aim is to now develop drugs that target and block that site, preventing the enzyme from functioning properly. In this way, they will potentially be able to slow the growth of C. difficile without necessarily killing it. The attempt to inhibit the growth of the bacteria rather than eliminating them entirely reflects the fact thatunder normal circumstances, the organism plays a rolein maintaining gastrointestinal health. Source: Massachusetts Institute of Technology. "Bacterial enzyme could become a new target for antibiotics." ScienceDaily. ScienceDaily, 17 March 2020. www.sciencedaily.com/releases/2020/03/200317130718.htm

88.1) The subunits of proteins are _____, joined together by _____ bonds called _____ bonds. A) amino acids; covalent; peptide B) nucleic acids; covalent; peptide C) amino acids; ionic; peptide D) monsaccharides; covalent; glycosidic E) amino acids; covalent; glycosidic

88.2)

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Which statement regarding HypD is FALSE?

A) It generates a precursor for the amino acid proline. B) It is uniquely synthesized by Clostridium difficile. C) It is involved in a dehydration chemical reaction. D) It may potentially be targeted for treating CDI. E) It is produced by a number of different gut bacteria.

88.3)

HypD is used by certain bacteria to generate ATP from amino acids.

⊚ ⊚

true false

88.4)

What is the significance of this research?

A) The researchers discovered a potential target for inhibiting growth of C. difficile. B) The authors discovered a new gut bacterium called Clostridium difficile. C) The research team discovered that Clostridium difficile can cause CDI. D) The researchers were able to reduce the growth of C. difficile in the gut. E) The teams proved that dysbiosis may lead to the development of CDI.

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Answer Key Test name: Chap 02_10e 1) FALSE 2) FALSE 3) FALSE 4) TRUE 5) FALSE 6) FALSE 7) FALSE 8) FALSE 9) TRUE 10) TRUE 11) [A] 12) C 13) B 14) C 15) A 16) E 17) A 18) A 19) E 20) A 21) C 22) D 23) B 24) B 25) C 26) B Version 1

27) B 28) B 29) E 30) E 31) C 32) C 33) B 34) B 35) C 36) C 37) D 38) C 39) C 40) C 41) A 42) D 43) C 44) B 45) B 46) E 47) A 48) B 49) C 50) B 51) C 52) B 53) E 54) B 55) C 56) C Version 1

57) A 58) E 59) C 60) A 61) A 62) C 63) B 64) E 65) B 66) B 67) A 68) D 69) B 70) A 71) A 72) E 73) A 74) A 75) A 76) B 77) A 78) A 79) A 80) A 81) A 82) A 83) A 84) A 85) A 86) A Version 1

87) Section Break 87.1) A 87.2) D 87.3) FALSE 87.4) B 87.5) C 88) Section Break 88.1) A 88.2) B 88.3) FALSE 88.4) A

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CHAPTER 3 TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Bacillus and Clostridium are medically relevant groups of bacteria that characteristically stain acid-fast. ⊚ ⊚

true false

LPS is found in the outer membrane of Gram-negative bacteria. ⊚ ⊚

true false

3) Penicillin affects the synthesis of phospholipids, thereby producing weak membranes and lysis of the bacteria. ⊚ ⊚

Endospores are involved in bacterial reproduction. ⊚ ⊚

true false

Lysosomes are bags of digestive enzymes found in prokaryotic cells. ⊚ ⊚

true false

Smooth endoplasmic reticulum is involved in protein synthesis. ⊚ ⊚

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true false

7) Mitochondria and chloroplasts are thought to have once been free-living bacteria that invaded another cell. ⊚ true ⊚ false

Cilia and flagella project from the cell and are not covered by cytoplasmic membrane. ⊚ ⊚

true false

Prokaryotes may ingest particles via phagocytosis. ⊚ ⊚

true false

MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 10) Select the CORRECT statement regarding eukaryotic cells. A) Eukaryotic cell are less complex than prokaryotic cells. B) They are members of the domains Bacteria and Archaea. C) Eukaryote cell are defined by the presence of a membrane bound nucleus. D) They are able to divide more rapidly than prokaryotic cells. E) Eukaryoticcell are defined by the presence of a cell wall.

11)

The two magnifying lenses found in a light microscope are the A) basic and transverse. B) small and large. C) ocular and objective. D) simple and phase. E) ocular and phase.

12)

The resolving power of a microscope is described as the ability of the microscope to

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A) separate clearly two objects that are very close together. B) magnify an object and its surroundings. C) separate the colors of an organism's internal structure. D) magnify structures at various depths in a tissue. E) combine the images of two objects that are very close together.

13)

In viewing a microscopic specimen, oil is used to A) increase the refraction AND increase the reflection. B) decrease the refraction AND increase the reflection. C) decrease the refraction AND increase the resolution. D) increase the reflection AND increase the resolution. E) increase the resolution AND increase the refraction.

14)

The use of oil with certain high-power objective lenses increases A) magnification. B) reflection. C) resolution. D) contrast. E) color.

15) Under standard conditions, the best way to observe more details in a microscopic specimen is to A) increase resolution. B) increase magnification. C) decrease magnification. D) increase scatter. E) decrease resolution.

16)

The microscope that allows the specimen to appear three-dimensional is the

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A) phase contrast microscope. B) differential interference contrast microscope. C) fluorescence microscope. D) transmission electron microscope. E) compound microscope.

17) Which of the following microscope types would be LEAST useful in viewing unstained living cells? A) Phase contrast B) Differential interference contrast C) Bright-field D) Dark-field E) Fluorescence

18)

Electron microscopes differ from light microscopes in that A) light replaces electrons. B) glass lenses replace electromagnetic lenses. C) resolution is lower. D) magnification is lower. E) magnification is higher.

19)

Specimens can be observed at the atomic level using a(n) A) scanning electron microscope. B) transmission electron microscope. C) atomic force microscope. D) fluorescence microscope. E) light microscope.

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20)

Why must the lenses and specimenbe in a vacuum when usingan electron microscope?

A) Electrons are particles but there are other particles in air as well. Without a vacuum, the electrons would strike and be scattered by the particles within the air. B) Electrons are highly radioactive, and the chamber must be completely sealed and under vacuum to prevent them from escaping and contaminating the lab area. C) The vacuum fixing the specimen to the slide grid. Without fixing the specimen by vacuum, it would slide off and we wouldn't be able to visualize it. D) The vacuum bends rays of visible light through the lenses and specimen so that details of the specimen can be clearly vizualized from all angles. E) None of the answer choices is true.

21) Why are the lenses of anelectron microscopeshaped like donuts (with a hole in the middle) rather than solid, like the lenses in a light microscope? A) A magnetic field cannot be applied across a completely solid object—there must be an opening within the object for the field to be applied through. B) Electrons are particles, and particles cannot travel through a solid item. The hole in the middle allows them to travel from the source of the electrons to the specimen. C) The electronswould destroy the electromagnet material unless there was a physical hole forthem to travel through on their way to the specimen. D) The user has to be able to physically look through the magnets to focus the beam of electrons onto the specimen, since the metal of the magnets is opaque. Without a hole in the middle, the user wouldn't be able to see! E) All of the answer choices are correct.

22)

Which microscope would be the BEST selection for examination of a virus? A) Confocal scanninglaser microscope B) Scanning electron microscope C) Dark-field lightmicroscope D) Atomic force microscope E) Compound light microscope

23)

Individual atoms on the surface of prepared samples can be observed by using the

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A) scanning electron microscope. B) dark-field microscope. C) atomic force microscope. D) phase contrast microscope. E) light microscope.

24)

Select the CORRECT statement regarding basic dyes. A) They have a negative charge. B) They have a positive charge. C) They are electrically neutral. D) They contain both positively and negatively charged particles. E) They are always blue or purple.

25)

Which of the following stains are considered differential? A) Capsule stain AND Gram stain. B) Flagella stain AND acid-fast stain. C) Acid-fast stain AND Gram stain. D) Acid-fast stain AND capsule stain. E) Gram stain AND flagellastain.

26)

The Gram stain and the endospore stain both use A) crystal violet. B) iodine. C) safranin. D) malachite green. E) acidic dyes.

27)

The CORRECT order of reagent use in the Gram stain reaction is

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A) safranin, alcohol, methylene blue, iodine. B) crystal violet, iodine, alcohol, safranin. C) methylene blue, alcohol, safranin, iodine. D) crystal violet, alcohol, iodine, safranin. E) alcohol, safranin, iodine, crystal violet

28)

Which may result in Gram-positive bacteria appearing to be Gram-negative? A) Decolorizing for too long AND using young bacterial cultures. B) Not decolorizingfor long enough AND using young bacterial cultures. C) Decolorizing for too long AND using old bacterial cultures. D) Not decolorizing for long enough AND using old bacterial cultures. E) Forgetting to decolorize AND using old bacterial cultures.

29) in

The major criterion used in placing bacteria into different groups is based on differences

A) cell wall structure. B) cell membrane permeability. C) presence or absence of flagella. D) detergent susceptibility. E) presence or absence of cytoplasmic membrane.

30)

In a basic staining procedure, which is the correct order of steps? A) Fix, smear, stain B) Smear, fix, stain C) Fix, stain, decolorize D) Smear, decolorize, stain E) Smear, stain, fix

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31)

Which statements are TRUE for the acid-fast stain?

A) It is useful for distinguishing a small group of organisms, including MycobacteriumAND it reflects differences in cytoplasmic membrane structure. B) It is useful for distinguishing a small group of organisms, including Mycobacterium AND it uses carbolfuchsin and methylene blue. C) It is useful for distinguishing a small group of organisms, including Mycobacterium AND it uses carbolfuchsin and safranin. D) It is useful for distinguishing a small group of organisms, including MycoplasmaAND it uses carbolfuchsin and methylene blue. E) It is useful for distinguishing a small group of organisms, including BacillusAND it uses crystal violet and safranin.

32)

Select the FALSE statement regarding capsules. A) Capsules may increase an organism's ability to cause disease. B) Capsules are typically "negatively" stained. C) Capsules may be stained as a wet mount. D) Capsules are usually composed of polysaccharides. E) Capsules take up stains well.

33)

The endospore stain A) is applicable to many groups of bacteria. B) usually shows the spores as pink structures among a background of blue cells. C) uses crystal violet as the primary stain. D) is an example of a negative stain. E) is applicable to only a few groups of bacteria.

34)

Which of the statements about immunofluorescence is FALSE?

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A) It uses fluorescently tagged molecules. B) It makes use ofthe specificity in binding of antibodies. C) It uses the dyes methylene blue and safranin. D) It would require a special UV microscope. E) Stained cells often appear bright yellow-green against a black background.

35)

Which terms refer to bacterial morphology? A) Bacillus AND polyhedral B) Coccus AND polyhedral C) Coccus AND Bacillus D) Polyhedral, coccus, AND Bacillus E) Coccus AND squarish

36)

Which is NOT true of the cytoplasmic membrane? A) It defines the boundaries of the cell. B) It is a selectively permeable barrier. C) It consists mainly of a fixed, static, phospholipid bilayer. D) It contains proteins used as selective gates and sensors. E) All of the answer choices are true.

37)

Which is TRUE of simple diffusion of water? A) Water usually enters a cell and produces a high osmotic pressure. B) Water usually leaves the cell and produces negative osmotic pressure. C) Water tends to enter and leave the cell equally, resulting in no pressure in the cell. D) Waterdiffusion ultimately relies on the selectively permeable nature of the cell wall. E) Water usually enters a cell and produces a very low osmotic pressure.

38)

The cytoplasmic membrane of both eukaryotes and prokaryotes functions to

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A) form rough and smooth endoplasmic reticulum. B) produce energy in the form of ATP. C) regulate movement of molecules that enter and leave the cell. D) form lysosomes, peroxisomes, and Golgi apparatus. E) produce peptidoglycanor chitin cell walls.

39) The proteins of bacteria that are involved in the movement of small molecules into the cell are called A) transport proteins, carriers, AND peptidases. B) transport proteins, permeases, AND carriers. C) permeases, carriers, AND peptidases. D) carriers, peptidases, AND porases. E) peptidases, porases, AND permeases.

40)

Most solutes pass through the cytoplasmic membrane via A) osmosis. B) diffusion. C) transport proteins. D) secretion. E) aquaporins.

41)

Facilitated diffusion and active transport A) both transport molecules into or out of a cell. B) are both not very specific as to which molecules are transported. C) both require a concentration gradient to function. D) both require use of energy in order to transport the molecules. E) both only transport molecules into a cell.

42)

The macromolecule found in the cell walls of all bacteria is

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A) lipid A. B) teichoic acid. C) peptidoglycan. D) glycocalyx. E) chitin.

43)

Which is/are TRUE regarding the cell wall of bacteria? A) It determines the shape of the bacteria. B) It prevents the bacteria from bursting. C) It contains peptidoglycan. D) It may be targeted by antimicrobials. E) All of the answer choices are true.

44)

Which amino acid is found only in the cell walls of bacteria? A) Glycerol B) L-form of glycine C) Diaminopimelic acid D) L-form of methionine E) D-form of methionine

45)

The cell wall of Gram-positive bacteria A) contains a thin layer of peptidoglycan. B) contains a thick layer of peptidoglycan. C) is an excellent barrier to most molecules. D) contains an outer membrane containing LPS. E) contains a thick layer of peptidoglycose.

46)

Which molecule(s) is (are) NOT associated with the cell wall of Gram-positive bacteria?

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A) Peptidoglycan B) D-form amino acids C) Teichoic acids D) Peptidoglycan, D-form amino acids, AND teichoic acids E) Lipopolysaccharide

47)

The cell wall of Gram-negative organisms

A) has a thick peptidoglycan layer ANDis characterized by an outer membrane containing LPS. B) has a thick peptidoglycan layer. C) has a thin peptidoglycan layer AND is characterized by an outer membrane containing LPS. D) has a thin peptidoglycan layer. E) is more permeable to various molecules than the Gram-positive cell wall.

48)

Endotoxin A) consists of lipopolysaccharide. B) determines bacterial shape. C) may have different effects depending on thebacterial species. D) is toxic due to the effects of the peptide side chains. E) is found in Gram-positive cells.

49)

Penicillin would be most effective against A) actively non-growing bacteria AND Gram-positive bacteria. B) non-growing bacteria AND Gram-negative bacteria. C) actively growing bacteria AND Gram-positive bacteria. D) actively growing bacteria AND Gram-negative bacteria. E) any actively growing bacteria.

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50)

Which of the following statements regarding peptidoglycan is TRUE? A) It may be digested by penicillin. B) It consists of a long string of NAG coupled to a long string of NAM. C) It may be digested by lysozyme. D) It is found in bacteria, archaea, and plants. E) It is only found in Gram-positive cells.

51)

Which of the following bacteria lack(s) a peptidoglycan cell wall? A) Treponema pallidum B) Mycobacterium tuberculosis C) Mycoplasma pneumoniae D) Staphylococcus aureus E) These all contain a cell wall—they are bacteria.

52)

The capsule

A) may be used for protection AND may be involved in movement. B) may be used to help the bacteria adhere to surfaces AND may be involved in movement. C) may be used for protection AND may be used to help the bacteria adhere to surfaces. D) may be involved in movement AND may be involved in energy production. E) may be involved in energy production AND may be used for protection.

53)

The structures used for motility in both eukaryotes and prokaryotes are A) cilia. B) flagella. C) pili. D) fimbriae. E) microvilli.

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54)

Movement in bacteria A) is directly to or away from a stimulus. B) relies on the beating of cilia. C) is often referred to as run and tumble. D) may involve pili AND may be referred to as twist and turn. E) is by means of flagella AND may be referred to as run and tumble.

55)

Extrachromasomal DNA is found in ______. A) mitochondria AND plasmids B) mitochondria only C) plasmids only D) the nucleoid AND nucleolus E) mitochondria AND nucleus

56)

Endospores are A) a dormant cell type. B) involved in bacterial reproduction. C) obligate intracellular parasites. D) sensitive to heat and dessication. E) made by all bacterial genera.

57)

Which of the following is TRUE regarding eukaryotic cells? A) They are more obviously compartmentalized than prokaryotes. B) They usually have a single circular supercoiled piece of DNA. C) They contain peptidoglycan in the cell wall. D) They have the same size ribosomes as prokaryotes. E) They all produce endospores in adverse conditions.

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58)

The membranes of eukaryotes and Mycoplasma A) contain peptidoglycan. B) contain sterols for strength. C) contain ergosterol. D) are fixed static structures. E) are phospholipid unilayers.

59)

Which is the CORRECT definition of phagocytosis? A) It is the ingestion of particles and may be performed by animal cells. B) It is the ingestion of particles and may be performed by bacteria. C) It is the secretion of proteins from a bacterium into the environment. D) It is the formation of a lysosome filled with peroxidases. E) It is the uptake of particles across the animal cell wall.

60)

The eukaryotic cell cytoskeleton

A) is a dynamic structure composed of microtubules, microfilaments, and intermediate filaments. B) is a static structure that gives a rigid, defined shape to the cell. C) consists of flagella, filaments and cilia that have been internalized. D) has no known function in an animal cell. E) is a dynamic structure composed of nucleic acids, phospholipids, and proteins.

61)

The nucleus

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A) is a single phospholipid membrane sac containing prokaryotic DNA. B) is a smaller structure contained within the eukaryotic nucleolus. C) is a double membrane sac containing DNA and is found in eukaryotes. D) cannot transport molecules to the cytoplasm due to the double membrane barrier. E) is a triple phospholipid membrane sac containing prokaryotic RNA.

62)

Which is NOT true of mitochondria and chloroplasts? A) They contain DNA and 70S ribosomes. B) They are found in all organisms. C) They are capable of performing protein synthesis. D) They generate ATP. E) They are membrane-bound organelles.

63)

An advantage of the smaller size of prokaryotes, compared to eukaryotes, is

A) high surface area relative to low cell volume AND slower growth rates. B) high surface area relative to low cell volume AND more rapid growth rates. C) more rapid growth rates AND compartmentalization of cellular processes. D) compartmentalization of cellular processes AND low surface area relative to low cell volume. E) more rapid growth rates AND low surface area relative to high cell volume.

64) You want to examine the structure of the protein coat of a virus by microscopy. Which microscope is your best choice, and why?

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A) The scanning electron microscope—it has excellent resolution and magnification (much higher than a light microscope), and can clearly visualize viruses. B) An atomic force microscope—this has the highest resolution and magnification of the microscopes we discussed andwe want to visualize a subcomponent of the virus particles. C) A fluorescent microscope—this will let us tag the virus protein coat with colored dyes in order to visualize it using this light microscope at 1000x. D) A bright-field light microscope—of course, we'll need to stain the viruses before we can visualize them against the bright white background at 1000x total magnification. E) The phase-contrast microscope—it has excellent contrast and magnification, and can be used to visualize viruses very clearly.

65) Your instructor wants you to bring in an example of a biofilm to your lab. Which choice is the best selection for bringing in an INTACT biofilm for further study? A) Disconnecting and bringing in the old, mildewed showerhead from your bathroom. B) Scraping the mold offthe shower curtain in yourbathroom into a paper cup using a butter knife. C) Using a toothpick to scrape plaque off of your teeth and smearing it onto a slide to bring in to lab. D) Wiping a sponge across a slimy boulder in a stream in a nearby park and bringing it in to lab. E) Wiping a sponge across your dog's teeth, smearing it onto a glass slide and bringing it in to lab.

66) A newly developed antibiotic drug shows promise by inhibiting prokaryotic 70S ribosomes in initial studies. However, when animal studies are begun, it's noted that the drug also inhibits growth of animal cells. Select the statement that may be explain howthis can be happening.

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A) The function of ribosomes is identical, no matter their size, so a drug that can affect 70S ribosomes will also impair 80S ribosomes. B) Mitochondria and chloroplasts possess 70S ribosomes. This drug might be impairing the activity of chloroplasts in animal cells. C) Mitochondria and chloroplasts possess 70S ribosomes. This drug might be impairing the activity of mitochondria in animal cells. D) Prokaryote cells are identical to animal cells; a drug that impacts one will also always impact the other. E) There really is no reasonable explanation for this observation; the experiment should be repeated to get a different outcome.

67) A research laboratory is investigating environmental factors that would inhibit the growth of Archaea. One question they have is whetheradding the antibiotic penicillin would be effective in controlling their growth. What do you think the outcome would be if they tried this? A) The penicillin wouldn't affect the Archaea because it targets peptidoglycan, which is not foundin their cell walls. B) The penicillin will inhibit peptidoglycan synthesis and thus cell wall formation in the Archaea, killing them. C) The penicillin will slow down the growth of the Archaea by damaging the cell wall, but they will be able to grow slowly. D) The penicillin willenhance the growth of the Archaea by providing a rich nutrientsource. E) The penicillin will inhibit cell division in the Archaea, forcing them to form endospores for survival.

68) A research laboratory is trying to produce new antibiotics. They develop a medication that detaches the hydrophilic heads from the phospholipids in cytoplasmic membranes. This drug

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A) would be highly toxic and completely useless for human beings and could never be used—our cells also have cytoplasmic membranes with hydrophilic head groups! B) would be highly toxic for human beings if taken orally, but might be useful as a topical antibiotic skin cream. The top layer of skin cells is dead anyway, so it wouldn't matter if the drugdamaged those cells. C) would be highly toxic only to bacteria, making it an excellent drug to develop and test further. Humans have a different phospholipid structure in their cytoplasmic membranes from bacteria. D) would generally not be toxic enough to damage Gram-negative bacteria, as their cytoplasmic membranes lie under a thick layer of peptidoglycan. However, it would be effective against Gram-positive cells. E) would not work against any bacteria, because they do not have a cytoplasmic membrane; however, it might be effective against helminths and viruses.

69) A new medication is developed that targets and binds to the lipid A portion of LPS in Gram-negative bacterial cells. This drug shows a high degree of binding and activity against purified lipid A in an experiment carried out in test tubes. Based on this information, A) we should fast-track this drug and get it out to physicians immediately to help prevent Gram-negative toxic/septic shock in humans. B) we should do some animal testing with intact Gram-negative cells and the medication before we jump to any conclusions. C) we should next proceed by repeating the experiment in test tubes using intact Gramnegative cells to see if the drug binds with the same strength. D) we should abandon the drug entirely. Binding to lipid A won't kill the bacteria, so the drug is useless to develop further. E) we should assume that the medication will be effective against all bacteria, including Mycoplasmas, and that it is ready for use in humans.

70) A new drug is developed that inhibits formation of flagellafilament by impairing production of the protein flagellin. Is this going to be an effective medication?

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A) Potentially yes—it could be used against some bacteria, but wouldn't be effective for those that don't use a flagellum to move around. B) Potentially yes, but only if it could be shown that the drug also didn't impair the production of the eukaryotic flagellum. C) Not at all—our eukaryotic cells depend on flagella to move around in our body, and this drug would impair that function. D) Not at all—bacterial flagella are produced using microtubules, not the protein flagellin. This drug would be useless in eliminating bacteria. E) Not at all—this medication would affect cells like the ciliated respiratory epithelial cells, and would cause potentially fatal side-effects.

71)

Please select the MISMATCHED pair regarding prokaryotes, microscopes and staining. A) Light microscope - 1,000-fold magnification B) Acid fast stain - differential C) Mycoplasmapneumoniae- pleomorphic cells D) Capsules and slime layers - phospholipids E) Membrane-bound organelles - fungi

72)

Please select the CORRECT pair regarding prokaryote cell structure and microscopy. A) Transmission electron microscope - surface details B) 70S ribosomes - protozoa C) Bacillus and Clostridium - endospores D) Peptidoglycan - bacteria and archaea E) Gram-positive cells - O antigen

73)

Which of the following is most abundant in bacterial cells?

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A) Glucose B) Water C) Peptidoglycan D) Phospholipid E) Glycoprotein

74) You discover an encapsulatedGram-positive, peritrichous, spore-forming bacillus. Which of the following describes the organism? A) Sphericalbacterium with a thin cell wall, a slime layer, and flagella distributed over its surface, that can form endosporesfor survival of adverse conditions. B) Rod-shaped bacterium with a thick cell wall, a capsule, and flagella distributed over its surface, that can form endosporesfor survival of adverse conditions. C) Sphericalbacterium with a thick cell wall, a slime layer, and a single flagellum at one side of the cell. D) Rod-shaped bacterium with a thin cell wall, a capsule, and single flagellum at one end, that can form endosporesfor survival in adverse conditions. E) Rod-shaped bacterium with a thin cell wall, a slime layer, and single flagellum at one end, that can form endosporesfor survival in adverse conditions.

75)

Chemotaxis refers to A) movement toward light. B) movementtoward a chemical. C) movement away from a chemical. D) movement in response to a chemical. E) movement of a chemical.

76) You discover a new pathogen which you visualize using a light microscope. A negative stain reveals a clear halo around the cells. This suggests to you that the organism

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A) is motile. B) has a capsule. C) is spherical in shape. D) is Gram-positive. E) has an LPS layer.

77)

Select the FALSE statement regarding the proton motor force.

A) The proton motive force is set up when protons are moved out of the cell by the electron transport chain. B) The energy of the proton motive force is harvested by mechanisms that allow protons to move back into the cell.  C) The energy of the proton motive force is used to drive certain cellular processes, including ATP synthesis.  D) The energy of the proton motive force is used to power certain transport systems and some forms of motility.  E) The proton motive force involves moving electrons from one side of the nuclear membrane to the other.

78)

Select the TRUE statement(s) about the proton motive force.

A) The proton motive force always involves the inner mitochondrial membrane. B) The proton motive force involves a pH gradient component. C) The proton motive force can be used for active transport processes. D) The proton motive force involves movement of hydrogen ions across the nuclear membrane by the electron transport chain. E) The proton motive force involves a pH gradient component AND the proton motive force can be used for active transport processes.

79) When doing a Gram stain, leavingwhich of the following on for twice as long as directed would have the most significant consequence?

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A) Alcohol B) Crystal violet C) Iodine D) Safranin E) Carbol fuchsin

80) A modified Gram-stain procedure uses Bismark brown as a counterstain instead of safranin. In this case, Gram-negative cells would appear _____, while Gram-positive cells would appear _____. A) brown; purple B) purple; purple C) pink; purple D) colorless; brown E) brown; colorless

81) A student mistakenly swapped the two stains in the Gram stain, thereby using safranin as the primary stain and crystal violet as the counterstain. With this error, Gram-positive cells would appear _____, while Gram-negative cells would appear _____. A) purple; purple B) pink; pink C) purple; colorless D) pink; colorless E) colorless; colorless

82) You correctly Gram-stain an unknown bacterium in your microbiology laboratory and see chains of purple spherical cells. Based on this information you can conclude that this organism is a

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A) Gram-positive streptococcus. B) Gram-negative streptoccocus. C) Gram-positive sphere. D) Gram-negative streptobacillus. E) Gram-negative diplococcus.

83) Consider the figure. Select the CORRECT statement regarding penicillin and the bacterial cell wall.

A) Penicillin will likely have a greater effect on the wall shown in panel A, which shows a Gram-positive cell wall. B) Penicillin will likely have a greater effect on the wall shown in panel A, which shows a Gram-negative cell wall. C) Penicillin will likely have a greater effect on the wall shown in panel B, which shows a Gram-negative cell wall. D) Penicillin will likely have a greater effect on the wall shown in panel B, which shows a Gram-positive cell wall. E) Penicillin will always have an equal effect on the cell walls shown in panel A and panel B .

84)

Please select the TRUE statement regarding cell walls of Archaea. A) Some archeae have pseudopeptidogylcan in their cell walls. B) Some archeae have peptidoglycan in their cell walls but most do not. C) Archaea do not have cell walls; they have only cell membranes. D) The archaeal cell wall is highly sensitive to penicillin. E) The archaeal cell wall resembles a Gram-negative bacterial cell wall.

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85)

Which of the following statements about flagella, pili and archaella is CORRECT? A) Bacteria move by means of flagella, while archaea move by means of archaella. B) Archaella and flagella are identical in structure and are used for attachment. C) Flagella are unique to bacteria; no other cell type has them. D) Sex pili are used for slow, gliding motion in archaea. E) Pili and fimbriae are both types of flagella used for movement.

86)

Why is a bacterial smear heated before staining? A) To fix (attach) the bacteria to the microscope slide. B) To kill the bacteria to make them harmless. C) To remove any capsules that would affect the staining method. D) To make the cell wall porous so dye can enter the cell. E) To differentiate between Gram-positive and Gram-negative cells.

87)

How does the function of the cell membrane differ from that of the cell wall?

A) The membrane is the permeability barrier that defines the cell boundary, while the wall provides strength to the cell to prevent it from lysing. B) The cell wall is the permeability barrier that defines the cell boundary, while the cell membrane provides strength to the cell to prevent it from lysing. C) The cell membrane and the cell wall have the identical function: they confer specific shape to the organism and control substances entering and leaving it. D) The cell membrane defines the boundary of the cell, while the only function of the cell wall is to provide a means to identify different types of bacteria. E) The cell wall is the pemeable boundary of the cell while the cell membrane is the impermeable boundary of the cell.

88) Given what you know about the bacterial cell wall, infections caused by which of the following would theoretically respond best to treatment with penicillin?

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A) Streptococcus pyogenes, a Gram-positive bacterium that can cause strep throat. B) Escherichia coli, aGram-negative bacterium that can cause urinary tract infections. C) Vibrio cholerae, a Gram-negative organism that causes serious diarrhea. D) Mycoplasma pneumoniae,a pleomorphic bacterium that causes pneumonia. E) Candida albicans, a yeast that can cause diaper rash in infants.

89) In the name E. coli O157:H7, "O157" refers to O antigen. From this, you can conclude that E. coli A) is Gram-negative. B) is Gram-positive. C) is a pathogen. D) is a coccus. E) has a capsule.

90) You do a chemical analysis of three bacterial samples. In one (sample A), you find phospholipids, peptidoglycan, O antigen and lipid A. In the second(sample B) you find peptidoglycan, phospholipids and teichoic acids. In the third (sample C)you find phospholipids but no peptidoglycan. Select the TRUE statement. A) Sample A - Gram-negative cell; Sample B - Gram-positive cell; Sample C Mycoplasma B) Sample A - Gram-positive cell; Sample B - Gram-negative cell; Sample C Mycoplasma C) Sample A - Gram-negative cell; Sample B - Gram-positive cell; Sample C - prion D) Sample A - Gram-negative cell; Sample B - Gram-positive cell; Sample C Streptococcus E) Sample A - Gram-positive cell; Sample B - Gram-negative cell; Sample C Mycobacterium

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91) Consider the Venn diagram pertaining to the three domains and select the INCORRECT characterization.Remember that characteristics shared by two or more items are found in the circle overlaps.

A) Mitochondria, 80S ribosomes, cell wall - G B) Peptidoglycan, 70S ribosomes, diplococcus - A C) Mitochondria, nucleus, unicellular - F D) Unicellular, ribosomes, DNA - E E) Prokaryote, 70S ribosomes, DNA - B

92) Why is it possible to use an antibiotic to target prokaryote protein synthesis without affecting eukaryote protein synthesis? A) Eukaryotes do not carry out protein synthesis or cell wall synthesis. B) Eukaryotes do not contain cell walls of peptidoglycan. C) Prokaryote ribosomes and eukaryote ribosomes are different. D) Prokaryotes do not contain mitochondria or Golgi apparatus. E) All prokaryotes are unicellular while eukaryotes can be uni- or multicellular.

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93) Consider the Venn diagram pertaining to the bacterial cell wall and select the INCORRECT characterization.Remember that characteristics shared by two or more items are found in the circle overlaps.

A) Stains with simple stain - B B) Lipid A and O antigen - C C) Peptidoglycan and teichoic acids - A D) Protein and carbohydrate - B E) Peptidoglycan and outer membrane - B

94)

If a cell is placed into a solution and water leaves the cell, the cell is in A) a hypertonic environment. B) hypotonic environment. C) isotonic environment. D) anoxygenic environment. E) even environment.

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SECTION BREAK. Answer all the part questions. 95) A patient comes to see you, complaining of a very sore throat. When you examine her, you find that she has a fever of 39.9oC, and you observe that her throat is extremely red, with pus on her tonsils. You swab the pus and make a slide, which you then send to the clinical lab for Gram staining. The lab sends back a report in which it is noted that the slide has manylong chains of round cells that have stained purple in color.

95.1)

Based on the Gram staining, you suspect that the patient has a _____ infection.

A) fungal B) bacterial C) protozoan D) algal E) prion

95.2) You inform the patient that the results of the Gram stain indicate to you that the bacteria in her throat are ______ in shape, and have a ______ cell wall. A) round; thin B) cylindrical; thick C) round; thick D) spiral; thick E) cylindrical; thin

95.3)

Your patient asks you whether you also observed viruses on the slide. You tell her

A) yes, but they are of no concern because viruses are never pathogenic. B) maybe, but there were too few to observe among the bacteria. C) maybe, but viruses cannot be observed without an electron microscope. D) unlikely, because viruses seldom cause sore throats in people. E) no, because viruses are always Gram negative.

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95.4) You perform a rapid strep test on the patient, which comes up positive. You tell her that she most likely has strep throat, caused by Streptococcus pyogenes. You prescribe penicillin for her, and tell her that this antibiotic is effective because it interferes with the synthesis of ______ by the pathogen. A) peptidoglycan B) capsule material C) ribosomes D) proteins E) ATP

95.5) As she is preparing to leave your office, the patient mentions that her brother had pneumonia a couple of years ago and that penicillin had not helped him. You ask her if she remembers the name of the organism causing her brother's illness and she tells you it was Mycoplasmasomething or other, that she can't quite remember. You tell her that the reason penicillin did not help her brother is that A) you know her brother did not take the full course of antibiotics, so some of the Mycoplasma cells survived. B) Mycoplasma species are Gram-negative, and penicillin cannot penetrate the LPS layer of these cells, so the cells survive. C) Mycoplasma species are acid-fast bacteria, so they have mycolic acids in the cell wall that penicillin does not destroy. D) Mycoplasma species do not have a peptidoglycan cell wall and are thus not impacted by penicillin. E) Mycoplasmas are viruses and antibiotics do not work against viral infections.

96) Petrus brings his 87-year old grandmother to the emergency department where you work. His grandmother has a fever, is dehydrated and confused, and complains of pain when urinating. Petrus reports that she has not been eating or drinking, but she has no signs or symptoms of gastrointestinal distress. You request blood samples and also a urine sample. You decide to keep Petrus' grandmotherin the hospitalso that she can be given intravenous fluids. You also want to wait for the lab test results before you decide whether she required additional treatment or if she can return home.

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96.1) When Petrus' grandmother's test results are sent to you, you discover that while her blood work is normal, her urine has Gram-negative bacilli in it. Based on this, you know that the cells are A) stained blue and are cylindrical in shape. B) stained purple and are cylindrical in shape. C) stained pink and are spherical in shape. D) stained pink and are cylindrical in shape. E) stained green and are oval in shape.

96.2) You explain to Petrus and his grandmother that the cause of her infection is likely E. coli, and that the organism produces ______ that allow it to attach to the epithelial cells of the urinary tract. A) flagella B) a slime layer C) a glycocalyx D) pili E) cilia

96.3) Petrus asks you what the Gram-negative result means and you explain that the bacteria causing his grandmother's UTI A) have a thin cell wall and an outer membrane which makes the cells less sensitive to the antibiotic penicillin. B) have a thick cell wall and an outer membrane which makes the cells less sensitive to the antibiotic penicillin. C) have no cell wall but they have a thick outer membrane which makes the cells less sensitive to the antibiotic penicillin. D) have a thin cell wall and an inner cell membrane which makes the cells less sensitive to penicillin. E) have no cell wall which makes the cells more sensitive to the antibiotic penicillin.

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96.4) The lab report also details the results of a negative stain performed on the bacteria in the urine sample. In this method, the background of the sample is stained, rather than the cells themselves. The report indicates that the cells have a clear halo around them, indicating the presence of a(n) ______. You explain to Petrus that this structure helps bacteria avoid ______, part of the immune response. A) endospore; phagocytosis B) flagellum; antibodies C) LPS; antibodies D) capsule; pinocytosis E) capsule; phagocytosis

97) Your roommate at college complains of a sore throat, fatigue, fever, cough, and chest pain. She thinks shehas a cold, although she has not had a runny nose or any sneezing, and she has been feeling bad for more than a week. You persuade her to go to the urgent care, which she does. She comes home with a prescription for penicillin, telling you that she was told that she likely has pneumonia, caused by Streptococcus pneumoniae. She takes the penicillin according to instruction but doesn't feel any better, so she goes back to the urgent care facility. This time, the physician's assistanton shift takes a sputum sample and sends it for analysis. He also prescribes tetracycline for your friend. This antibiotic targets protein synthesis. Your friend takes the medication and recovers fully.

97.1) You are a microbiology student. You tell your roommate that Streptococcus pneumoniae A) is a bacterium that appears as chains of round cells when viewed with a microscope. B) is a virus that appears as chains of round cells when viewed with a microscope. C) is a bacterium that appears as pairs of rod-shaped cells when viewed with a microscope. D) is a protozoan that appears as clusters of round cells when viewed with a microscope. E) is a virus that cannot be viewed except with an electron microscope.

97.2) You explain to your roommate that penicillin is an antibiotic that interferes with the synthesis of peptidoglycan. Peptidoglycan

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A) is composed of glycan chains linked by tetrapeptidesAND is unique to pathogens. B) is composed of glycan chains linked by tetrapeptides AND is unique to bacteria and archaea. C) is composed of glycan chains linked by tetrapeptides AND is unique to bacteria. D) is composed of glycan chainsand phospholipids AND is unique to bacteria. E) contains phospholipids and carbohydrate chains AND is unique to prokaryotes.

97.3) You tell your friendyou think she may actually have pneumonia caused by Mycoplasmapneumoniae, a ______ organism that lacks a ______. A) spherical; peptidoglycan cell wall B) pleomorphic; phospholipid bilayer C) bacillus; capsule D) pleomorphic; peptidoglycan cell wall E) pleomorphic; nucleoid

97.4) How do you explain to your friend why tetracycline treated her infection but penicillin did not? A) Mycoplasma pneumoniaehas no lipopolysaccharide so is not impacted by penicillin, an inhibitor ofphospholipidsynthesis. However, the organism carries out protein synthesis, so is affected by tetracycline, which interferes with this process. B) Mycoplasma pneumoniaehas no proteins so is not impacted by penicillin, an inhibitor ofproteinsynthesis. However, the organism carries out peptidoglycan synthesis, so is affected by tetracycline, which interferes with this process. C) Mycoplasma pneumoniaehas no cell wall so is not impacted by penicillin, an inhibitor ofpeptidoglycansynthesis. However, the organism carries out protein synthesis, so is affected by tetracycline, which interferes with this process. D) Mycoplasma pneumoniaeis a Gram-positive cell, so has a peptidoglycan layer too thick to be impacted by penicillin. It can only be treated with tetracycline, which is a much stronger antibiotic. E) Mycoplasma pneumoniaeis an RNA virusso is not impacted by penicillin, an inhibitor of DNAsynthesis. However, tetracycline which interferes with DNA replication, so destroys this infectious agent.

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97.5) Mycoplasma pneumoniae is naturally resistant to penicillin because it lacks a peptidoglycan cell wall and penicillin interferes with peptidoglycan synthesis. ⊚ ⊚

true false

98) A bacterium commonly used for scientific studies is E. coli,a Gram-negative rod. As is typical with Gram-negative cells, E. coli has a thin wall composed of peptidoglycan, and an outer membrane composed of phospholipids on the inner surface and lipopolysaccharides (LPS) on the outer surface. For a long time now, scientists have known that the cell wall confers rigidity and shape to bacterial cells. However, the outer membrane of Gram-negative cells has been thought to simply be a lipid covering that isimportant from a medical standpoint: it forms a selective barrierthat can make it challenging for certain antibiotics to enter the cells and as a result, Gramnegative cells tend to be more resistant to antibiotics than Gram-positive cells, which lack the outer membrane. The outer membrane has not been thought to play a role in the morphology of the cells. Now however, collaborating scientists from several universities have shown that in fact, the outer membrane plays a significant role in physically protecting Gram-negative bacteria. The team, led by K.C. Huang at Stanford University, exposed E. coli cells to various stresses. In one experiment, they removed the bacterial cell wall, but left the outer membrane intact. Initially, all the cells lost their regular shape, and rounded up into what is known as L-forms. The team expected the cells to die (they take up water and burst) but many survived, and to the researchers’ surprise, those cells multiplied and eventually regained their original shape. In other experiments, the team left the cell wall intact but reduced the pressure inside the bacterial cells; they assumed that the walls would shrink and that the cells would lose their rod shape, but in fact they did not. It seemed that the outer membrane was able to maintain cell shape. In a different approach, the scientists exposed E. coli cells to alternating increases and decreases in pressure for two hours. Intact E. coli cells were completely unaffected by this treatment; however, if the team weakened the outer membrane of the cells and repeated the experiment, the cells soon died. It has come as a surprise to understand that the outer membrane of Gram-negative cells has such amazing strength. The significance of this research is that the outer membrane could provide a new target for antimicrobial medications; developing drugs that destroy the outer membrane of Gram-negative cells could provide a novel approach to treating infections caused by these organisms. Source:Stanford University. "Bacterial armor could be a new target for antibiotics." ScienceDaily. ScienceDaily, 18 July 2018. www.sciencedaily.com/releases/2018/07/180718131145.htm.

98.1) Version 1

Please select the TRUE statement regarding the bacterial cell wall. 34

A) The Gram-positive wall has a thick layer of peptidoglycan; the Gram-negative cell wall has a thin peptidoglycan layer and an outer lipid membrane. B) The Gram-positive wall has a thick layer of peptidoglycan; the Gram-negative cell wall has a thin peptidoglycan layer and an outer protein membrane. C) The Gram-negative wall has a thick layer of peptidoglycan; the Gram-positive cell wall has a thin peptidoglycan layer and an outer lipid membrane. D) The Gram-negative outer membrane has an inner lipopolysaccharide layer and an outer phospholipid layer. E) Cell shape is maintained by the peptidoglycan cell wall in Gram-positive cells but by the cell membrane in Gram-negative cells.

98.2)

Please select the FALSE statements regarding a Gram-negative cell wall.

A) It contains teichoic acids and lipoteichoic acids. B) The wall retains a pink color in the Gram-stain procedure. C) Outside the wall is a unique lipoloysaccharide layer. D) It confers shape to the bacterial cell. E) It is composed of a mesh-like material called peptidoglycan.

98.3)

What did the researchers demonstrate in this work?

A) The outer membrane of Gram-negative cells is very strong and helps maintain cell shape and integrity. B) E. coli is a Gram-negative bacterium that has an outer, impermeable LPS membrane. C) If the cell wall of E. coli is removed, the cells all take up water and burst; no cells survive. D) The cytoplasmic membrane of E. coli provides a novel target for antimicrobial drugs. E) The Gram-negative outer membrane has an inner lipopolysaccharide layer and an outer phospholipid layer.

98.4)

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What is the significance of this research?

A) The researchers suggest that drugs that destroy the outer membrane of Gramnegative cells could provide a novel therapy approach. B) The researchers suggest that drugs that destroy the cell wall of Gram-negative cells may provide a novel therapeutic approach. C) The researchers show that drugs that destroy the cytoplasmic membrane of Grampositive cells can be used as a novel way to kill those cells. D) The researchers prove that the outer membrane of Gram-negative cells is impermeable, making the cells impossible to destroy with any kind of medication. E) This research indicates that it is likely impossible to destroy many Gram-positive bacteria, because they do not have an outer membrane for targeting.

98.5)

Which of the following is demonstrated TRUE in this research?

A) E. coli that had the outer wall removed immediately underwent osmotic lysis. B) E. coli with a weakened outer membrane were unable to tolerate repeated stress events. C) E. coli with an intact outer membrane were unable to tolerate repeated stress events. D) Drugs targeting the outer membrane could be used against both Gram-positive and Gram-negative cells. E) L-forms are rod-shaped bacteria with their peptidoglycan layer removed.

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Answer Key Test name: Chap 03_10e 1) FALSE 2) TRUE 3) FALSE 4) FALSE 5) FALSE 6) FALSE 7) TRUE 8) FALSE 9) FALSE 10) C 11) C 12) A 13) C 14) C 15) A 16) B 17) C 18) E 19) C 20) A 21) B 22) B 23) C 24) B 25) C 26) C Version 1

27) B 28) C 29) A 30) B 31) B 32) E 33) E 34) C 35) C 36) C 37) A 38) C 39) B 40) C 41) A 42) C 43) E 44) C 45) B 46) E 47) C 48) A 49) C 50) C 51) C 52) C 53) B 54) E 55) A 56) A Version 1

57) A 58) B 59) A 60) A 61) C 62) B 63) B 64) B 65) A 66) C 67) A 68) B 69) C 70) A 71) D 72) C 73) B 74) B 75) D 76) B 77) E 78) E 79) A 80) A 81) A 82) A 83) A 84) A 85) A 86) A Version 1

87) A 88) A 89) A 90) A 91) C 92) C 93) E 94) A 95) Section Break 95.1) B 95.2) C 95.3) C 95.4) A 95.5) D 96) Section Break 96.1) D 96.2) D 96.3) A 96.4) E 97) Section Break 97.1) A 97.2) C 97.3) D 97.4) C 97.5) TRUE 98) Section Break 98.1) A 98.2) A 98.3) A 98.4) A Version 1

98.5) B

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CHAPTER 4 TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) It is assumed that every colony observed on a streak plate arose from a single bacterium. ⊚ ⊚

true false

In microbiology, growth usually refers to an increase in size of the bacteria. ⊚ ⊚

true false

There are five stages of growth in an open system of culture. ⊚ true ⊚ false

Secondary metabolites produced during bacterial growth may be antibiotics. ⊚ ⊚

A single bacterial cell may multiply to form a visible colony on a culture medium. ⊚ ⊚

true false

Prokaryotes are the only organisms able to use atmospheric nitrogen as a nitrogen source. ⊚ ⊚

true false

Freezing is an effective means of destroying bacteria. ⊚ ⊚

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true false

One would expect most strict anaerobic organisms to have superoxide dismutase. ⊚ ⊚

true false

Differential media only allow certain bacteria to grow. ⊚ ⊚

true false

MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 10) All the bacterial cells that result from the replication of a single bacterial organism are referred to as a A) mixed population. B) pure culture. C) lag culture. D) mutant culture. E) single culture.

11)

The scientist that contributed most to the development of pure culture techniques was A) Alexander Fleming. B) Louis Pasteur. C) Edward Jenner. D) Robert Koch. E) Paul Ehrlich.

12)

The solidifying agent used most successfully in bacterial nutrient media is

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A) gelatin. B) peptone. C) agar. D) starch. E) agarose.

13)

Prokaryotic cells divide by a process known as A) conjugation. B) mitosis. C) binary fusion. D) binary fission. E) meiosis.

14)

In nature, bacteria A) rarely grow in close association with many other kinds of organisms. B) always go through a very short exponential phase. C) always synthesize structures such as slime layers. D) may adhere to surfaces by means of pili and slime layers. E) All of the answer choices are correct.

15)

Which of the statements about biofilmsis TRUE? A) Biofilms are very rarely involved in human bacterial infections. B) Biofilms may protect organisms against harmful chemicals. C) Biofilms are a peptidoglycan-encased community of microorganisms. D) Biofilms may significantly inhibitbioremediation efforts. E) Biofilms are very seldom found in a natural environment.

16)

The simplest technique for isolating bacteria is referred to as the

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A) streak-plate method. B) pour-plate method. C) serial dilution method. D) most probable number method. E) bacterial growth method.

17)

Bacteria may be stored for several months A) on a slant in the refrigerator, frozen in agar AND in broth at 37°C. B) in broth at 37°C, on a slant in the refrigerator ANDfrozen in glycerol solution. C) on a slant in the refrigerator, frozen in glycerol solution AND freeze-dried. D) freeze-dried, in broth at 37°C AND frozen in agar. E) freeze-dried, frozen in glycerol solutionAND in broth at 37°C.

18) In the growth curve of a bacteria population, the bacteria are rapidly increasing in number in the A) lag phase. B) exponential (log) phase. C) stationary phase. D) decline phase. E) death phase.

19)

During which phase of growth are bacteria most susceptible to antibiotics? A) Lag B) Stationary C) Exponential (log) D) Decline E) Infection

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20)

When doing experiments with bacteria, A) it is usually not necessary to standardize which stage of growth is used. B) it is best to use colonies, as all cells in a colony are at the same growth stage. C) it is best to use bacteria from the same stage of growth. D) the age of the bacteria is not important. E) it is best to use mixed populations and biofilms.

21) During which phase of the bacterial growth curve does the total number of viable (live) cells decline? A) Stationary B) Lag C) Exponential D) Death E) Infection

22)

The lag phase of the bacterial growth curve is characterized by A) a decrease in cell mass. B) dormant, metabolically inactive cells. C) metabolically active cells. D) vigorously dividing cells. E) spore-forming cells.

23)

Late log phase of the bacterial growth curve A) is characterized by the production of primary metabolites. B) is characterized by the production of secondary metabolites. C) is a transition into the death phase. D) shows a decline in cell numbers. E) is characterized by germination of endospores.

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24) During which phase of the bacterial growth curve does a bacterial population become much more resistant to harmful conditions? A) Lag phase B) Exponential phase C) Stationary phase D) Late log phase E) Decline phase

25) A urine sample with more than 100,000 organisms is considered indicative of infection. A urine sample containing 5,000 bacteria, with a generation time of 30 minutes, sits for 3 hours before finally being assayed. How many bacteria will then be present within the sample? A) 320,000 B) 100,000 C) 64,000 D) 15,000 E) 10,000

26) A pure culture in exponential growth phase has a bacterial concentration of 6.4 x 10 cells/ml. If the bacterium has a generation time of 1 hour, how long ago was the cell concentration 8.0 x 10 7 cells/ml? A) 1 hour B) 2 hours C) 3 hours D) 4 hours E) 24 hours

27)

In a rapidly multiplying bacterial population, cell numbers increase

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A) arithmetically. B) logarithmically. C) linearly. D) indirectly. E) additionally.

28)

Generally the proteins of thermophiles A) resist denaturation. B) react more efficiently with DNA. C) are easily denatured. D) have very few amino acids. E) are larger than those of mesophiles.

29)

A hot tub (with a water temperature of104°F or 40°C) would most likely contain A) psychrophiles. B) freezophiles. C) mesophiles. D) thermophiles. E) hyperthermophiles.

30)

The optimal temperature for most human pathogens might be expected to range from A) 20–45°C. B) 35–40°C. C) 15–25°C. D) 93–98.6°C. E) 35–40°F

31)

Bacteria on fish caught in the Arctic Ocean would

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A) be freezophiles ANDcontinue to grow while the fish is in the refrigerator. B) be mesophiles AND wouldcontinue to grow while the fish is in the refrigerator. C) be mesophiles AND wouldnot grow very well in the refrigerator. D) be psychrophiles AND wouldcontinue to grow while the fish is in the refrigerator. E) be thermophiles AND would not grow very well in the refrigerator.

32) Mycobacterium leprae is typically found infecting the ears, toes, and fingers of its host due to its A) requirement for well-oxygenated blood. B) easy access to those body parts. C) need for cooler temperatures. D) long incubation period. E) environmental distribution.

33)

Organisms that require gaseous oxygen for metabolism are referred to as A) facultative aerobes. B) obligate aerobes. C) facultative anaerobes. D) microaerobes. E) obligate anaerobes.

34)

Which of the following is (are) obligate aerobes? A) Clostridium botulinum B) Escherichia coli C) Micrococcus luteus D) Helicobacter pylori E) All of the answer choices are correct.

35)

Organisms that are indifferent to the presence of oxygen and do not use it are

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A) aerotolerant anaerobes. B) facultative anaerobes. C) obligate aerobes. D) microaerophiles. E) obligate anaerobes.

36)

The enzymes that deal with toxic oxygen-containing molecules are A) glycolase AND superoxide dismutase. B) superoxide dismutaseAND cytochrome oxidase. C) superoxide dismutase AND catalase. D) catalase AND cytochrome oxidase. E) cytochrome oxidase AND glycolase.

37)

Shake tubes are used to determine the A) pH requirements for bacterial growth. B) temperature requirements for bacterial growth. C) oxygen requirements for bacterial growth. D) salt requirements for bacterial growth. E) nutrient requirements for bacterial growth.

38)

The optimum pH for growth of most species of bacteria is ______. A) pH 5 B) pH 7 C) pH 9 D) pH 6 E) pH 1

39)

High concentrations of salt and sugar in foods

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A) are useful in preserving the food AND tend to force water into a cell, causing plasmolysis. B) have no effect on water availability AND are useful in preserving the food. C) are useful in preserving the food AND tend to draw water out of a cell. D) are useful in preserving the food AND forcebacteria to divide. E) tend to force water into a cell, causing plasmolysis AND forcebacteria to divide.

40)

Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur may be considered A) minor elements. B) major elements. C) neutral elements. D) acidic elements. E) trace elements.

41)

Which of the following are TRUE regarding trace elements?

A) They include zinc, copper, and manganese AND they may be needed for enzyme function. B) They include zinc, copper, and manganese AND they are required in large amounts. C) They may be needed for enzyme function AND they are involved in maintaining pH in the cell. D) They are required in large amounts AND they may be needed for enzyme function. E) They are involved in maintaining pH in the cell AND they include zinc, copper, and manganese.

42) Small organic molecules that must be provided to bacteria in order for them to grow are called

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A) minerals. B) growth factors. C) water. D) vitamins. E) ions.

43) The prefix photo- in the term photoautotroph indicates that an organism will make use of ______ for energy purposes. A) chemicals B) organics C) light D) inorganics E) water

44)

Organisms that use organic molecules as their source of carbon are called A) chemotrophs. B) heterotrophs. C) organoheterotrophs. D) autotrophs. E) organoautotrophs.

45)

Organisms may derive energy from A) sunlight AND temperature gradients. B) sunlight AND metabolizing chemical compounds. C) metabolizing chemical compounds AND temperature gradients. D) temperature gradients AND pH gradients. E) sunlight AND pH gradients.

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46)

Organisms that use CO

2 as their source of carbon are called

A) organotrophs. B) heterotrophs. C) autotrophs. D) chemotrophs. E) carbonotrophs.

47)

Which of the statements regarding chemoorganoheterotrophs is/are CORRECT? A) They use sunlight as an energy source. B) They use preformed organic molecules as a carbon source AND light as an energy

source. C) They use preformed organic molecules as an energy source. D) They use inorganic chemicals as an energy source. E) They use preformed organic molecules as a carbon source AND as an energy source.

48)

What would true about an organism called Bacillus fastidiosus? A) It might be expected to be very flexible in its growth requirements. B) It might be expected to be very strict in its growth requirements. C) It could probably be grown on a minimal medium. D) It might be expected to have a spherical shape. E) It might be expected to depend on sunlight for energy.

49)

Which is TRUE of peptone?

A) It is a hydrolysate of carbohydrates used in growth media. B) It is a hydrolysate of proteins used in growth media. C) It consists of a water extract of beef. D) It consists of a mix of monosaccharides and oligosaccharides. E) It is a hydrolysate of proteins used in growth media AND it consists of a water extract of beef.

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50)

Medically important bacteria are often A) grown on agar containing blood AND grown at 4°C. B) grown at 37°C AND grown at a pH of 5. C) grown on agar containing blood AND grown at 37°C. D) grown on agar containing chocolate AND grown at 4°C. E) grown at a pH of 5 AND grown at 4°C.

51)

Products that limit pH changes are often incorporated into media and are referred to as A) enzymes. B) buffers. C) bases. D) acids. E) neutrifiers.

52) a(n)

A medium that inhibits the growth of organisms other than the one being sought is called

A) synthetic medium. B) specific culture medium. C) selective medium. D) enrichment medium. E) differential medium.

53)

MacConkey agar is

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A) a selective medium. B) a selective and differential medium. C) a differential medium. D) an enrichment medium. E) an anaerobic medium.

54)

Candle jars are used to A) prevent candles from melting and going out. B) provide an atmosphere with increased CO 2 levels. C) stimulate the growth of obligate anaerobes. D) prevent the growth of obligate aerobes. E) enhance the growth of microaerophiles and aerobes.

55)

In the cultivation of microaerophilic and anaerobic bacteria,

A) a(n) candle/anaerobe jar is sufficient. B) atmospheric oxygen in a(n) candle/anaerobe jar is converted to water. C) a packet containing chemicals that generate CO2 and hydrogen is used in a(n) candle/anaerobic jar. D) oxidizing agents are incorporated into the media that react with oxygen. E) selective and differential media must always be used.

56)

Which of the folllowing is TRUE about agar? A) It has chemical and physical properties that make it almost ideal for solidifying

media. B) It is a useful nutrient source for most bacteria. C) It is a hydrolysate of carbohydrates and proteins. D) It stays liquid through the typical range of incubation temperatures. E) It only solidifies if it is cooled in a refrigerator for 48 hours.

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57)

Agar replaced gelatin as the solidifying agent for media because A) agar provides nutrientsfor rapidbacterial growth. B) fewer bacteria can break down agar compared with gelatin. C) agar is solid at temperatures as high as 90°C. D) agar provides a pH range from 4–11. E) agar is much easier to obtain than gelatin.

58) A microbe is discovered growing near a deep sea thermal vent. When researchers bring a sample up to the surface and try to grow it in a lab at room temperature in a regular incubator, they are unsuccessful. Why? A) The pressure isn't the same at sea level as it is on the ocean floor and the microbe may require a very specific pressure. B) Oxygen concentrations are very different between the two environments—it's possible the microbe is a strict anaerobe and cannot survive regular atmospheric oxygen levels. C) The salt concentration in the media the researchers are usingmay be different from that of sea water. This might be causing osmotic pressure differences that the microbe can't tolerate. D) The temperature is probably different—the thermal vent would be very hot, while these researchers are trying to grow this microbe at room temperature. E) All of the answer choices are correct.

59) You are a microbiologist working for a pharmaceutical company and discover a new secreted metabolite that can serve as a medication. Your company asks you to oversee the production of the metabolite. Which of the following does NOT need to be considered if you need to grow 5,000 liter cultures of bacteria for the purpose of harvesting the metabolite they secrete?

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A) The death rate ofthe bacteria after stationary phase is complete. B) The ideal rate ofinput of new nutrients into the culture to maintain the cells in log phase. C) The ideal rate ofpulling off some of the culture in order to maintain the cells in logphase. D) The best way to mix the large vat in order to keepnutrient levels, temperature, and oxygen levels constant. E) The best way to keep the pH of theentire mixture at the ideal level to promote log phase growth.

60) You are working in a clinical laboratory in a hospital setting. You're handed a throat swab from a patient. You are told specifically that the physician is only interested in the presence and type of Gram positive cells. Identification isn't the main goal here—just a first step to work towards determining what Gram positive cells might be there. What might you do first to go about working towards this goal? A) Perform a Gram stain on the patient's sample. B) Streak the samplefor isolation on a tryptic soy agar general purpose medium plate. C) Streak the sample for isolation on a medium that is selective for Gram positive cells. D) Grow the microbeson the swab by inoculating a tryptic soy broth liquid medium tube. E) Perform an acid-fast stain on the patient's sample.

61) A physician sends a fecal sample to your lab, and wants to know if there are lactose fermenting microbes in it. How might you determine if these microbes are present or not from this mixed-microbe specimen?

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A) Streak the samplefor isolation on Thayer-Martin agar (which contains lactose and particularantibiotics for selectivity). B) Streak the sample for isolation on a blood agar plate (which contains lactose and red blood cells that enrich the culture for iron). C) Streak the samplefor isolation on a MacConkey agar plate (which contains lactose and a pHindicator that turns pink when acid byproducts are present). D) Either Thayer-Martinagar or blood agar would work, as long as the plates are incubated in an anaerobic chamber. E) None of the answer choices are correct—there's no way to reliably determine this feature from the specimen given.

62) You are in charge of water quality for your city's water treatment plant. Which is the most efficient and cheapest method of determining the number of viable (living) bacteria in the water coming out of your plant? A) Direct countsusing a microscope and a counting chamber. B) Using a Coulter counter machine followed by placing the membrane in a growth medium for counting after incubation. C) Performing serial dilutionsand doing spread plate counts. D) Using membrane filtration followed by placing the membrane in a growth medium for colony counts after incubation. E) Biochemical analysis of secondary metabolites in the water that are given produced by the bacteria.

63) You take spectrophotometer absorbance readings of a culture of E. coli cells growing in tryptic soy broth (TSB) at 2, 4 and 6 hours. Your absorbance readings clearly indicate a lag phase, a log phase, and a stationary phase. You come back in and take additional readings at 8, 10, 12, 14, and 16 hours, but the absorbance number remains the same. Shouldn't it start coming down as the closed batch culture enters death phase? What's the most likely explanation for whatis happening?

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A) Something is likely wrong with the spectrophotometer and it isn't measuring the correct values. Perhaps something is on the detector, making it register falsely high absorbance numbers. B) Absorbance indicatescell number,but does not differentiate betweenlivedead cells. The presence of dead cellskeeps the absorbance high even into the death phase. C) E. coli just has a long generation time and grows extremely slowly. After 16 hours the cells are still in stationary phase, so the cell numbers remainconstant, as expected. D) Perhaps there's a big smudge of something on the culture tube that is blocking some of the light. This would cause a high value for every timepoint. E) There is no point in measuring the absorbance of the culture because the cells are bacterial. It would make more sense to measure the transmission value.

64) of O

Clostridium paradoxum grows optimally at 55°C, pH 9.3; it will not grow in the presence 2. Please select the TRUE statement about this organism. A) It is spherical in shape. B) It is a psychrophile. C) It is an obligate anaerobe. D) It is an acidophile. E) It is an aerotolerant anaerobe.

65) You are determining the number of colony forming units (CFUs) for Susan, who has a urinary tract infection (UTI). You added 1 mL of Susan's urine sample to 99 mL ofdiluent, and spread 0.1 mL of that dilution on a culture medium. After appropriate incubation, you count 143colonieson the plate. What was the concentration ofbacteriain the original urine sample? A) 1.43 cells/ mL B) 1.43 x 10 2 cells/ mL C) 1.43 x 10 3cells/ mL D) 1.43 x 10 5 cells/ mL E) Cannot be determined

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66) Eosin methylene blue agar (EMB) is a selective and differential medium. The dyes in the medium inhibit most Gram-positive organisms. Gram-negative organisms such as the coliformsgrow on this medium. Coliforms that are fecal in origin produce colonies with a metallic green color on EMB, while those that are non-fecal producecolorless colonies. You plate a urine sampleonto an EMB plate and incubate it. Metallic green colonies develop. From this, you can conclude that A) the sample contains bacteria thatare Gram-negative AND are non-fecal in origin. B) the sample contains bacteria thatare Gram-negative AND are fecal in origin. C) the sample contains bacteria thatare Gram-positive AND are fecal in origin. D) the bacteria in the colonies are Gram-positive AND are rod-shaped. E) normal microbiotain the bladder is fecal in origin AND is aerobic.

67) You are culturing a new bacterium in the laboratory. You cannot find any glucose it the lab when you are making growth medium, so you decide to use honey instead. You add twice as much honey than is called for in the medium recipe, because you want to give the organism the best opportunity or growth. To your surprise, the organism does not grow on your modified medium. Select the most likely explanation. A) The growth medium became hypotonic with the addition of so much honey; the bacteria underwent plasmolysis and died. B) The growth medium became hypertonic with the addition of so much honey; the bacteria underwent plasmolysis and died. C) The growth medium became halophilic with the addition of so much honey; the bacteria underwent plasmolysis and died. D) The growth medium became hypertonic with the addition of so much honey; the bacteria underwent osmotic lysis and died. E) The growth medium became hypotonic with the addition of so much honey; the bacteria underwent simple diffusionand burst.

68) A halophilic, aerobic mesophilehas a generation time of 20minutes. You place 1x10 4of these organismson an appropriate solid medium, and incubate the plate for 100 minutes. Select the FALSE statement.

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A) The growth medium contains NaCl. B) The organism will grow at 40 oC. C) After incubation, a colony on the plate contains 3.2 x 10 5 cells. D) After incubation, a colony on the plate contains 5 x 10 4 cells. E) The organism produces superoxide dismutase and catalase.

69)

Please select the INCORRECT pair regarding stages of bacterial growth.

A) Lag phase -stage characterized by extensive macromolecule and ATP synthesis but no increase in cell number. B) Log phase -stage during which bacterial cells divide at a rapidly increasing rate. C) Stationary phase -stage in which the number of viable cells remains constant. D) Death phase -stage in which the number of viable cells decreases at an exponential rate. E) Period of decline - stage during which most cells die, but a few are able to grow.

70)

Which of the following best defines the human intestinal tract? A) An open system containing a complex medium. B) An open system containing a selective medium. C) A closed system containing a complex medium. D) A closed system containing a chemically defined medium. E) An alternately open and closed system with a differential medium.

71) Clostridium tetani, an obligate anaerobe, is placed onto the same type of solid culture medium but incubated under two different conditions: aerobic and anaerobic. Which of the following best predicts what would be observed after 48 hours?

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A) Colony growth on the culture plate in aerobic conditions; no colony growth on culture plate in anaerobic conditions. B) Colony growth on the culture plate in anaerobic conditions; no colony growth on culture plate in aerobic conditions. C) Growth of large colonies on plate in aerobic conditions; growth of smaller colonies on plate in anaerobic conditions. D) Growth of large colonies on plate in anaerobic conditions; growth of smaller colonies on plate in aerobic conditions. E) No growth on either of the plates.

72) E. coli, a mesophile, is grown at two different temperatures. Which conditions would be appropriate for optimal growth of this organism? A) 220 minutes at 10°C; 20 minutes at 37°C B) 20 minutes at 10°C; 220 minutes at 37°C C) 20 minutes at 45°C; 220 minutes at 65°C D) 220 minutes at 37°C; 20 minutes at 95°C E) 220 minutes at 10°C; 1 minute at 65°C

73) Thioglycolate medium is used to determine the oxygen requirements of a microorganism. You inoculate a tube of this medium with a bacterium and observe dense growth at the surface of the tube, with turbidity throughout the rest of the tube. From this you can conclude that A) the organism is a facultative anaerobe. B) the organism is an obligate aerobe. C) the organism is an obligate anaerobe. D) the tubes should be incubated for more time. E) the organim is fastidious.

74) You leave several tomatoes in your refrigerator when you go on vacation. When you get home, the tomatoes are covered in microbial growth. Select the best description for these microbes.

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A) They are acidophilic, psyhrotrophic aerobes. B) They are acidophilic, psyhrophilic aerobes. C) They are acidophilic, psyhrophilic anaerobes. D) They are neutrophilic, thermophilic aerobes. E) They are acidophilic, psyhrotrophic Gram-positive aerobes.

75) Neisseria gonorrhoeae is routinely grown on Thayer-Martin agar. This medium contains red blood cells that are lysed by heat to release growth factors, as well as a variety of antibiotics, including vancomycin and polymyxin. What can you conclude about this medium? A) It is selective. B) It is differential. C) It is selective AND differential. D) It is thermophilic. E) It is fastidious.

76) Which of the following would absolutely NOT grow on a petri dish incubated on a bench top in the microbiology laboratory? A) Obligate anaerobe B) Obligate aerobe C) Facultative anaerobe D) Microaerophile E) Aerotolerant anaerobe

77) You go on a trip to the South Pole, Antarctica. Unfortunately, you catch a bacterial infection from a tea mate while you’re there, and you experience sore throat, fever, productive cough, and headache. The organism causing your illness is a

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A) psychrophile. B) mesophile. C) thermophile. D) psychrotroph. E) anaerobe.

SECTION BREAK. Answer all the part questions. 78) Mrs. Thomascomes to the emergency department where you work, complaining of nausea and vomiting, bloody diarrhea, abdominal discomfort and fever. She tells you that she went out to a picnic the previous day, where barbecued chicken was served. Mrs. Thomas is a vegan, so she ate only salad. You thinkthat she likely has salmonellosis, caused by the bacteriumSalmonella enterica. However, the presence of blood in her stool causes you concern, and you want to rule out the possibility that patient has shigellosis, caused byShigellabacterial species.

78.1) You take a fecal sample from Mrs. Thomas, and send it to the lab for analysis. You tell her that the technicians will do a variety of tests to confirm the identity of the organism causing her illness. The first thing that will be done is to inoculate some of her stool sample onto a medium called hektoenenteric (HE) agar. On this medium, Shigella species produce blue-green colonies, while Salmonella produces blue-green colonies with a black center, and most Gram-positive bacteria do not grow at all. You explain to Mrs. Thomas that this type of medium is called a(n) ______ medium. A) selective B) differential C) enrichment D) selective and differential E) differential and enrichment

78.2) On HE medium, Shigellaspecies produce blue-green colonies, while Salmonellaproduces blue-green colonies with a black center. There are two noticeable types of colonies growing on the hektoen enteric (HE) medium in Mrs. Thomas' test. One type of colonyis greenish in color. This leads you to conclude that the bacteria in these colonies

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A) is Gram-negative and is likely Shigella. B) is Gram-negative and is likely Salmonella. C) is Gram-positive and is likely Shigella. D) is Gram-positiveand is likely Salmonella. E) is Gram-neutral and is likely Salmonella.

78.3) In addition to the few Shigellacolonies that are noted, there are also abundant salmon pink colonies, around which the medium has turned yellow, losing its original bluecolor. You know that hektoen enteric agar must contain ______. A) lactose B) a pH indicator C) a weak acid D) malachite green E) penicillin

78.4) The colonies of interest in this case are the blue-green presumptive Shigella colonies. However, growth on hektoen enteric agar is not sufficient for definitive identification. Further tests are needed. First, the lab technicians need to prepare larger numbers of Shigella from your patient's stool sample, and thenthey need to ensure that they are culturing a single species. The methods used to do this are ______, followed by ______. A) streak plating; pour plates B) enrichment culture; Gram staining C) Gram staining; enrichment culture D) Gram staining; capsule staining E) enrichment culture; streak plating

78.5) Shigellaspecies and Salmonella species are classified as facultative anaerobes. You know that given this information, the bacteria in your patient's fecal culture will grow best

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A) in the absence of oxygen. B) in the presence of oxygen. C) at low levels of oxygen. D) in high levels of carbon dioxide. E) if catalase is added to the medium.

79) Mr. Jones comes to your clinic complaining of genital discharge. He admits that he recently had unprotected sex with an old friend with whom he reconnected after a school reunion. You suspect that he may have gonorrhea. You take a sample of the discharge and send it to the hospital lab for analysis.

79.1) The causative organism of gonorrhea is Neisseria gonorrhoeae, a fastidious, Gram-negative diplococcus. What does fastidious mean in this context? A) An organism with complex nutritional requirements. B) An organism that requires oxygen for growth. C) An organism that survives in the presence of specific antibiotics. D) An organism that only grows in pure culture. E) An organism that requires a living host.

79.2) The lab technicians culture the sample on Thayer-Martin agar. This complex medium contains 5% sheep blood and a combination of antibiotics. This medium is A) differential. B) selective AND differential. C) selective. D) aerobic. E) chemically defined.

79.3) Thayer-Martin agar typically contains a combination of antibiotics: vancomycin, colistin, nystatin, and trimethoprim. Please select the TRUE statement.

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A) The antibiotics in Thayer-Martin agar do not kill bacteria. B) The antibiotics in the Thayer-Martin medium lysethe sheep RBCs. C) Neisseria gonorrhoeae is not sensitive to the included antibiotics. D) Fastidious bacteria are never impacted by common antibiotics. E) Sheep blood cells in a growth medium protects bacteria from the impact of antibiotics.

79.4) If you are asked to make 200 mL of Thayer-Martin agar, who much sheep's blood would you add to the medium? Recall that thiscomplex medium contains 5% sheep blood. A) 10% B) 5 mL C) 10 mL D) Random quantities E) 10,000 RBCs

80) A cluster of cases of legionellosishave occurred in your neighborhood. People with the illness have cough, fever, shortness of breath, chest pain and sometimes diarrhea. The illness is caused by the bacterium Legionella pneumophila, a facultative intracellular parasite that survives in certain ameba. The organism has an absolute requirement for L-cysteine.

80.1) Diagnosis of legionellosis depends partly on culture of the causative agent from medical samples. Typically, the organism is grown on buffered charcoal yeast extract (BCYE) agar. What essential component must this medium have to ensure growth of L. pneumophila? A) red blood cells B) chlorine C) NaCl D) cysteine E) All of the answer choices are correct.

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80.2) L. pneumophila is widespread and is foundin various water sources, including hot tubs, water cooling towers, swimming pools, grocery store misters, and shower water. Select the FALSEstatement regarding the organism, given this information. A) It survives in the presence of chlorine. B) It is a mesophile. C) It is an obligate anaerobe. D) It can survive in water pipes. E) It is a mesophile AND it can survive the presence of chlorine.

80.3) In some labs, samples containing suspected L. pneumophila are cultured on traditional BCYE medium containing L-cysteine, as well as BCYE medium lacking Lcysteine. How would L. pneumohila be identified in this situation? A) Compare the two plates. Colonies that grow on traditional BYCE medium but not on BYCE medium lacking cysteinearelikely L. pneumophila. B) Compare the two plates. Colonies that grow on BYCE medium lacking cysteinebut not on traditional BYCE medium arelikely L. pneumophila. C) Compare the two plates. Colonies that grow on both traditional BYCE medium and on BYCE medium lacking cysteinearelikely L. pneumophila. D) Compare the two plates. Colonies that do not grow on traditional BYCE medium or on BYCE medium lacking cysteine, but do grow on nutrient agararelikely L. pneumophila. E) Compare the two plates. Colonies that grow on traditional BYCE medium and are blue, yellow or cyan in colorarelikely L. pneumophila.

80.4) A modification of the BCYE medium used to culture L. pneumophila is BCYE with DGVP. Thismedium contains glycine, polymixinB (an antifungal agent), and and vancomycin (antibiotic), as well as two dyes (bromocreson purple and bromthymol blue) that facilitate identification of the organism based on colony color. What type of medium is BCYEwith DGVP?

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A) Selective B) Differential C) Selective AND differential D) Anaerobic AND selective E) Anaerobic

81) You work as an RN in the emerency department(ED) at a large regional hospital. A 37year-old man is admittedexhibitingdizziness, dry mouth, blurred vision, and slurred speech. He also reportsabdominal symptoms, including pain, nausea, vomiting, and diarrhea.The patient'sfamily tells you that he was recently at a church potluck, where heate bread, homemade tomato-beefstew and home-canned green beans.Based on the patient's signs and symptoms, the physician with whom you are workingsuspects botulism, a neurological disease that is caused by consumption of a toxin produced bythe Gram-positive, spore-forming, obligate anaerobic bacterium Clostridium boltulinum. The patient develops breathing difficulty and is placed on a mechanical ventilator. A stool sample from the patient is cultured on amedium called CBI. Thismedium contains theantibiotics cycloserine, sulfamethoxazoleand trimethoprim asinhibitory agents—C. botulinumhas a high level ofresistanceto these drugs. Some normal fecal bacteria can grow on CBI medium but they producecolonies that are easy to idenitify because they are pinpoint (tiny). The stool sample shows colonygrowth on the CBI agar,confirmingthe presence of C. botulinum. The stool sample,leftover stew and green beans are also tested for botulinum toxin; the stool sample and the green beans test positive for the toxin, butthe stew is negative for the toxin. The testresults confirmthe diagnosis of foodborne botulism and the patient is treated appropriately. He remains in the hospital for several weeks, before being discharged.

81.1) Clostridium botulinum grows optimally at 26-30oC, pH higher than 4.6 and 1% oxygen. How should it be classified? A) Obligate anaerobe, neutrophile, mesophile B) Obligate anaerobe, neutrophile, psychrophile C) Obligate aerobe, neutrophile, mesophile D) Microaerophile, alkaliphile, mesophile E) Microaerophile, alkaliphile, thermophile

81.2)

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Select the CORRECT statement regarding CBI medium.

A) It is both selective AND differential. The antibiotics make it a selective medium, and the colony characteristics on it make it differential. B) It is selective only. The antibiotics make it a selective medium, preventing the growth of any other microbes. C) It is differential. Non- Clostridial organisms produce pinpoint colonies, while Clostridial colonies are larger. D) It is neither selective NOR differential. Any types of bacteria can grow on this medium. E) It is selective. CBI is an anaerobic medium specifically used for isolating Clostridium.

81.3) What is the likely reason that Clostridium botulinum was found in the homecanned green beans but not the tomato-beef stew? A) Green beans have a neutral pH but the tomatoes in the beef stew made it acidic and unfavorable for bacterial growth. B) Green beans have an acidic pH but the tomatoes in the beef stew made it basic and unfavorable for bacterial growth. C) There are no nutrients in beef. C. botulinum growth is supported by the abundance of nutrients in green beans. D) Green beans, being plants, are antibiotic free. All beef has high levels of penicillin in it that suppresses bacterial growth. E) Bacteria cannot digest meat proteins but they can use plants proteins under aerobic conditions.

81.4)

Why is botulism primarily a problem in canned foods rather than fresh ones?

A) Canned food is never sterilized, so bacteria such as C. botulinum thrive in cans. B) Fresh food contains normal microbiota that prevents the growth of pathogens such as C. botulinum. C) The canning process dramatically reduces the pH of food, and C. botulinum is an acidophile. D) The causative agent is an obligate anaerobe—there is no O 2 in a full can. E) All of the answer choices are correct.

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81.5)

Select the CORRECT statement that explains the results of this case study.

A) The green beans were home-canned. The person making them likely did not use a high enough temperature for the canning process. B) The green beans were home-canned. The person making them likely did not add enough antibiotics for the canning process. C) The green beans were home-canned. The person making them likely did not use a low enough temperature for the canning process. D) The tomato-beef stew was store bought. All commercial food suppliers are required to autoclave their produce, so the beef was safe. E) The tomato-beef stew was store bought. All commercial food suppliers are required to add antibiotics their produce, so the beef was safe.

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Answer Key Test name: Chap 04_10e 1) TRUE 2) FALSE 3) FALSE 4) TRUE 5) TRUE 6) TRUE 7) FALSE 8) FALSE 9) FALSE 10) B 11) D 12) C 13) D 14) D 15) B 16) A 17) C 18) B 19) C 20) C 21) D 22) C 23) B 24) D 25) A

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Recall that the number of cells at any given time Nt is equal to the initial number of cells N0 times 2n where n is the number of generations. The final equation is Nt = N0x 2n. Calculate the number of generations by multiplying the time interval elapsed by the generation time. 26) C Recall that the number of cells at any given time Nt is equal to the initial number of cells N0 times 2n where n is the number of generations. The final equation is Nt = N0 x 2n. Calculate the number of generations by multiplying the time interval elapsed by the generation time. 27) B 28) A 29) C 30) B 31) D 32) C 33) B 34) C 35) A 36) C 37) C 38) B 39) C 40) B 41) A 42) B 43) C 44) B 45) B 46) C 47) E Version 1

48) B 49) B 50) C 51) B 52) C 53) B 54) B 55) B 56) A 57) B 58) E 59) A 60) A 61) C 62) D 63) B 64) C 65) D 66) B 67) B 68) D 69) B 70) A 71) B 72) A 73) A 74) A 75) A 76) A 77) B Version 1

78) Section Break 78.1) D 78.2) A 78.3) B 78.4) E 78.5) B 79) Section Break 79.1) A 79.2) C 79.3) C 79.4) C 80) Section Break 80.1) D 80.2) C 80.3) A 80.4) C 81) Section Break 81.1) A 81.2) A 81.3) A 81.4) D 81.5) A

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CHAPTER 5 TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) Prions are easily destroyed by common sterilization procedures. ⊚ true ⊚ false

The endospores of Pseudomonas make that organism very difficult to kill. ⊚ ⊚

Upon heat treatment, bacteria die at a constant proportion. ⊚ ⊚

true false

Boiling is very effective at removing most common waterborne pathogens. ⊚ ⊚

true false

Heat treatment is an effective method for sterilization or disinfection of all materials. ⊚ ⊚

true false

The more bacteria one starts with, the longer it will take to kill them all. ⊚ ⊚

true false

Pasteurization results in the sterilization of food products. ⊚ ⊚

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true false

Dry heat takes a much shorter time to sterilize material than wet heat. ⊚ ⊚

true false

100% ethanol is twice as effective as 60% ethanol at controlling bacteria. ⊚ ⊚

true false

10) Generally, heavy metals, except silver, have been proven to be too toxic for use on human tissue and are no longer used medically. ⊚ ⊚

11)

Hydrogen peroxide may be used as a sterilant on living tissue. ⊚ ⊚

12)

true false

Cold temperatures and freezing are very effective in killing bacteria. ⊚ ⊚

true false

13) Organic acids, such as benzoic acid, are often added to foods to prevent microbial growth. ⊚ ⊚

14)

true false

The only protective gear required for working in a BSL-4 laboratory is a lab coat.

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⊚ ⊚

15)

true false

When you eat food that has been irradiated, you are exposed to radiation. ⊚ ⊚

true false

MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 16) Lister developed his ideas on prevention of infection during medical proceduresafter studying the work of A) Koch. B) Pasteur. C) Jenner. D) Fleming. E) Ehrlich.

17)

One of the first chemicals used by Lister to prevent surgical infections was A) alcohol. B) iodine. C) carbolic acid. D) mercury. E) soap.

18)

The process of killing or removing all of the microorganisms in or on a material is called

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A) sterilization. B) disinfection. C) sanitation. D) antisepsis. E) degerming.

19)

A sterile item is free of A) microbes, viruses, AND prions. B) all viable microbes, endospores, AND viruses. C) endospores, viruses, AND prions. D) microbes, endospores, AND prions. E) prions only.

20)

A suffix used to describe a killing action would be A) -static. B) -cidal. C) -cillin. D) -tion. E) -side.

21)

Pasteurization

A) is the use of high moist heat to remove all bacteria and viruses from fresh food products for safety. B) is a process that uses intense cold to kill only pathogenic microorganisms on packaged foods. C) is the use of heatto reduce numbers of pathogenic/spoilage bacteria in a food item to a safelevel. D) is a process that uses short bursts of radiation to kill microorganisms on foods. E) is a mild heating process used to preserve only milk and milk products.

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22) Hand washing with plain soap is very useful in controlling spread of microorganisms because A) plain soap is bacteriostaticand inhibits bacterial growth. B) it is very effective at the mechanical removal of microorganisms. C) all soaps are virucidal and killall viruses. D) plain soap is bactericidal and kills all bacteria. E) all soaps are bacteriostatic and kill endospores.

23)

Which is TRUE of HAIs? A) They are acquired by susceptible peopleat various social events. B) They are acquired by susceptible peoplein the hospital. C) They are acquired by susceptible peopleat sporting events. D) They occur in communities butvery seldom occur in hospitals. E) They occur most frequently in isolated communities.

24)

To reduce or eliminate disease-/spoilage-causing organisms, food is often treated with A) heat. B) chemical additives. C) radiation. D) cold. E) All of the answer choices are correct.

25)

Which of the followingare resistant to destruction by typical disinfection methods? A) Clostridium endospores B) Escherichia coli C) Enveloped viruses D) Mycoplasmaspecies E) Vegetative bacteria

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26) is

A common environmental organism that may even grow in certain chemical disinfectants

A) Escherichia coli. B) Streptococcus pneumoniae. C) Pseudomonas aeruginosa. D) Influenza virus (enveloped). E) Adenoviruses (non-enveloped).

27)

When treated with heat or chemicals, bacteria will A) all die immediately. B) die at a constant rate. C) form endospores and survive. D) die at a geometric rate. E) develop resistance.

28) In a one D process, how many D values would it take to reduce a population of 10 cells to one survivor? A) 2 B) 4 C) 5 D) 10 E) 100

29) If a process kills 90% of the organisms per minute, how many minutes would it take to kill all organisms when starting with 100,000 organisms?

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A) 6 minutes B) 3 minutes C) 2 minutes D) 1 minute E) 60 minutes

30)

Microbial death rates may be affected by A) pH. B) temperature. C) the presence of organics. D) growth ina biofilm. E) All of the answer choices are correct.

31)

Moist heat kills microorganisms by A) irreversible denaturation of proteins. B) destruction of carbohydrates in the cell wall. C) denaturation of nucleic acids. D) dissolving the capsule. E) destruction of the nuclear membrane.

32)

Boiling is not reliable for sterilization because A) heat-sensitive instruments may be destroyed. B) water boils at a higher temperature at lower altitudes. C) heat-resistant endospores are unaffected. D) viruses are more sensitive to heat than bacteria. E) most pathogens are heat stable.

33)

Typical conditions used for sterilization are

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A) 100°C at 15 psi for 10 minutes. B) 121°C at 15 psi for 15 minutes. C) 80°C at 15 psi for 15 minutes. D) 72°C at 5 psi for 15 seconds. E) 100°C at 1.5 psi for 10 seconds.

34)

Which are essentially equivalent treatments? A) Dry 200°C heat for 1.5 hours; wet 121°C heat for 15 minutes B) Dry 160°C heat for 1.0 hour; wet 200°C heat for 30 minutes C) Dry 121°C heat for 1.5 hours; wet 200°C heat for 15 minutes D) Dry 100°C heat for 2.0 hours; wet 100°C heat for 30 minutes E) Dry 100°C heat for 30 minutes; wet 100°C heat for 30 minutes

35)

Which of the following is/are not (a) sterilization method(s)? A) Hot air oven B) Autoclave C) Pasteurization D) Filtration E) Vaping

36)

Which of the following methods sterilizes the materials? A) Pasteurization B) High-temperature-short-time pasteurization (HTST) C) Ultrahigh-temperature (UHT) method D) Medium-temperature-intermediate-time pasteurization (MTIT) E) Low-temperature-short-time pasteurization (LTST)

37)

The autoclave treatment may be monitored by

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A) heat-sensitive tape AND pressure indicators. B) heat-resistant endospores of Bacillus subtilis. C) pressure indicators AND waiting for contaminants to appear on freshly poured media. D) waiting for contaminants to appear on freshly poured media. E) heat-sensitive tape AND heat-resistant endospores ofGeobacillus stearothermophilus.

38)

Commercial canning processes

A) destroy Clostridium botulinum spores,are especially needed on low acid foods, ANDare 12D processes (designed to kill 1012 endospores). B) kill all endospores,are especially needed on moderately acidic foods, ANDare 12D processes (designed to killendospores in 12 days). C) are especially needed on low acid foods, are 12D processes (designed to kill 1012 endospores), AND destroy E. coli endospores. D) destroy E. coli endospores, are especially needed on acidic foods, AND are 12D (designed to kill 1012 endospores)processes. E) destroy Clostridium botulinum spores,are especially needed on very acidic foods, ANDare 12D processes (designed to kill endospores in 12 days).

39)

Oxidation of proteins is achieved most readily A) by moist heat. B) by moist heat under pressure. C) in a hot air oven. D) in the presence of organics. E) in a refrigerator.

40)

A common application of dry heat in the microbiology laboratory is to

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A) prepare specimens for study. B) sterilize media. C) sterilize plastics. D) sterilize the inoculating loop. E) sterilizePetri dishes.

41)

Liquid media containing heat-sensitive components would best be sterilized by A) ultraviolet light at 500 nm. B) membrane filtration. C) freezing. D) lyophilization. E) refrigeration.

42)

Generally, membrane filters are used for all of the following EXCEPT A) removing bacteria from liquids. B) removing enzymes from liquids. C) removing microorganisms from gases. D) removing spoilage agents from alcoholic beverages. E) removing bacteria from nutrient broths.

43)

Gamma rays cause biological damage in living systems by A) producing reactive molecules such as superoxide. B) causing breakdown ribosomes and peptidoglycan. C) introducing life-threatening toxins. D) making the substance radioactive. E) causing a cell to multiply too fast for its environment.

44)

Gamma irradiation

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A) has not been approved for use on any types of food. B) can be used to either sterilize or pasteurize, depending on the dose of radiation. C) leaves some dangerous radioactive particles in the treated substance. D) usually kills by generating heat and denaturing proteins and ribosomes. E) frequently causes a product to become carcinogenic (cancer-causing).

45)

Which would be most effective against Pseudomonas? A) Alcohol B) Radiation C) Quaternary ammonium compounds D) Iodophors E) Hand soap

46)

Ultraviolet radiation at the bactericidal wavelength destroys bacteria by A) destroying endospores. B) damaging nucleic acid. C) preventing spore formation. D) denaturing proteins. E) disrupting ribosomes.

47)

Microwaves do not kill organisms directly but kill by A) the heat they generate in a product. B) generating free radicals. C) generating toxins. D) creating thymine dimers. E) decreasing the pressure in the cells.

48)

Chemical germicides

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A) may react irreversibly with proteins/enzymes. B) may react with cytoplasmic membranes or viral envelopes. C) may be disinfecting or even sterilizing. D) are sensitive to dilution factor, time of contact, and temperature of use. E) All of the answer choices are true.

49)

Alcohols are not reliably effective at destroying A) vegetative bacteria AND endospores. B) enveloped viruses AND endospores. C) non-enveloped viruses AND enveloped viruses. D) non-enveloped viruses AND endospores. E) non-enveloped viruses AND vegetative cells

50)

Chlorhexidine A) is an aldehyde. B) is extensively used in antiseptics. C) is ineffective against vegetative bacteria. D) is limited in use due to its high toxicity. E) commonly causes adverse side effects.

51)

Glutaraldehyde A) is very good for use on heat-sensitive medical items. B) inactivates lipids. C) does not affect non-enveloped viruses. D) is used in gaseous form. E) kills bacteria but does not affect endospores.

52)

Ethylene oxide is a gas that

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A) is very useful for sterilizing heat- or moisture-sensitive items. B) is harmless to people and issafe to use. C) is used as a 37% aqueous solution. D) destroys microbes excludingendospores and viruses. E) reacts with nucleic acids in a cell.

53)

Which of the statements regarding chlorine is CORRECT? A) It readily reacts with organics to produce potentially carcinogenic trihalomethanes. B) It is very expensive but is able to destroy all types of microorganisms. C) It is unaffected by the presence of organic material. D) It is ineffective when diluted. E) It can be used very effectively as an antiseptic.

54)

Which is TRUE of iodine? A) It readily kills endospores. B) It may be used as an antiseptic but not as a disinfectant. C) It can be used at any dilution. D) It is usually found as tinctures or iodophors. E) It may be used as a disinfectant but not as an antiseptic.

55)

Select the FALSE statement regarding hydrogen peroxide. A) It is a sterilant for inanimate objects and is quickly inactivated on living tissue. B) It leaves no toxic residue and is safe on materials such as glass and plastic. C) It is broken down by catalase into water and oxygen. D) It is even more effective when used in combination with peracetic acid. E) It immediately kills all bacteria when applied to a wound.

56)

Which statement regarding phenolics is TRUE?

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A) They denature proteins and destroy cytoplasmic membranes. B) They become ineffective in the presence of detergents or organic material. C) Phenolics such as triclosan have very limited commercial use. D) They reliably inactivate all groups of viruses. E) They are ineffective against Mycobacterium species.

57)

Hexachlorophene has been particularly effective against A) Staphylococcus aureus. B) Micrococcus aureus. C) Escherichia coli. D) Enterobacter aerogenes. E) Streptococcus pneumoniae.

58)

Quaternary ammonium compounds are A) cationic detergents that help wash surfaces. B) attracted to the positive charge on the microbial cell surface. C) toxic and cannot be used on food preparation surfaces. D) very effective against endospores and non-enveloped viruses. E) anionic detergents that help wash surfaces.

59)

Which of the following is (are) considered when selecting a germicidal chemical?

A) Toxicity AND cost, BUT not environmental impact or compatability with the material being treated. B) Cost, toxicity AND compatibilitywith the material being treated. C) Compatibility with the material being treated, cost AND environmental impact. D) Environmental impact, toxicity AND cost BUT not environmental impact. E) Environmental impact, toxicity, cost AND compatibility with the material being treated.

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60)

Silver sulfadiazine, which is a combination of silver and a sulfa drug, is used to A) disinfect water for drinking. B) prevent infection of surgical wounds. C) prevent infection of second- and third-degree burns. D) counteract lead poisoning. E) prevent ophthalmia neonatorum in babies.

61) Compounds of tin, mercury, arsenic, and copper are no longer used to prevent microbial growth in cooling water primarily because A) antibiotics are cheaper. B) other chemicals were shown to be much more effective. C) microbes developed resistance to these metals. D) their use contributes to serious pollution of natural waters. E) All of the answer choices are correct.

62)

The most important function of nitrites in processed foods is to A) prevent browning of the product. B) inhibit the germination of Clostridium botulinum endospores. C) prevent carcinogen formation. D) make the food more acidic. E) destroy cell membranes of potential pathogens.

63)

Please select the INCORRECTLY matched pair.

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A) Bacterial endospores - highly resistant. B) D-value - time to destroy 10% of microbes present. C) Critical instrument - scalpels and needles. D) Incineration - burns cells to ashes. E) Sterilants -destroy all microbes including endospores and viruses.

64)

Please select the TRUE statement regarding preservation of perishable products.

A) Nitrites and nitrates are always converted into carcinogens by intestinal bacteria. B) Refrigeration destroys most pathogens and all spoilage microorganisms. C) Salting and drying increase the availability of water in food above the limits required for growth of most microbes.  D) Drying stops microbial growth, and reliably kills all bacteria and fungi in or on foods.  E) Bacterial resistance to some of the chemicals included to perishable products has been reported.

65) Which of the following lists the organisms/structures from MOST resistant to killing to LEAST resistant to killing? A) Prions, endospores, Mycobacterium species, Pseudomonas species, enveloped viruses B) Endospores, Mycobacterium species, Pseudomonas species, enveloped viruses, prions C) Endospores, Pseudomonas species, enveloped viruses, Mycobacterium species, prions D) Enveloped viruses, endospores, Pseudomonas species, Mycobacterium species, prions E) Prions, enveloped viruses, endospores, Pseudomonas species, Mycobacterium species

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66) Which of the following is listed in correct order for LEAST resistant to killing to MOST resistant to killing? A) COVID-19 coronavirus, poliovirus, Pseudomonas aeruginosa, Mycobacterium tuberculosis, Giardia lamblia cysts, Clostridium botulinum spores B) Clostridium botulinum spores, COVID-19 coronavirus, poliovirus, Pseudomonas aeruginosa, Mycobacterium tuberculosis, Giardia lamblia cysts C) COVID-19 coronavirus, poliovirus, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Giardia lamblia cysts, Clostridium botulinum spores D) Poliovirus, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Giardia lamblia cysts, Clostridium botulinum spores,COVID-19 coronavirus E) Poliovirus, COVID-19 coronavirus, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Giardia lamblia cysts, Clostridium botulinum spores

67) Why are low-acid foods processed at a higher temperature than high-acid foods in canning? A) Higher temperature ensures destruction of endospores in low-acid food; if spores are not destroyed, they could germinate and give rise to Clostrium botulinum cells that would produce disease-causing toxin. B) Lower temperature ensures destruction of endospores in low-acid food; if spores are not destroyed, they could germinate and Clostrium botulinum cells would grow and produce disease-causing toxin. C) Clostridium botulinum endospores are extremely sensitive to acid and are quickly destroyed in high-acid foods; any remaining vegetative bacterial cells are easily killed by low heat. D) Although Clostridium botulinum endospores are extremely sensitive to acid and are quickly destroyed in high-acid foods, vegetative cells are acid-resistant and must be killed by high heat. E) Low-acid foods have to be processed at a high temperature to ensure that all pathogens that occur naturally in canned foods are completely eliminated, without changing the taste of the food.

68)

The D value is defined as

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A) the time it takes to kill 90% of bacteria in a population. B) the time it takes for 90% of bacteria in a population to divide. C) the time it takes to kill 10% of bacteria in a population of 90. D) the time it takes to kill 99.9% of bacteria in a population. E) the time is takes to reduce a population of dividing bacteria by 9%.

69) You are making a hand sanitizer using aloe gel and alcohol. Which is the most appropriate concentration of alcohol in your final product? A) 70% B) 10% C) 100% D) 50% E) 25%

70)

Please select the FALSE statement regarding sterilization.

A) A high-level disinfectant cannot be used as a sterilant. B) Critical items must be sterilized before use. C) Low numbers of endospores may remain on semi-critical items. D) Standard sterilization procedures do not destroy prions. E) Quaternary ammonium compounds can be used to disinfect food preparation surfaces.

71)

Which of the following pieces of medical equipment requires sterilization? A) Scalpel B) Blood pressure cuff C) Stethoscope D) Thermometer E) All of the choices are correct.

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72) Which of the following is the term used to describe the time needed to kill all the bacteria in a population at a particular temperature? A) D value B) Death reduction time C) T value D) Thermal death time E) Thermal reduction time

73) You work in a BSL-4 laboratory. What type of organism do you work with in this setting? A) Easily transmitted pathogen likely to cause fatal disease. B) Pathogen spread by respiratory droplets, likely to cause serious disease. C) Pathogenic microbe not known to cause disease in humans. D) Moderate-risk pathogen that may cause disease but doesn't spread easily. E) Any type of human pathogen that may cause any type of disease.

74)

Which of the following does not kill microbes but physically removes them? A) Filtration B) Pasteurization C) Microwaving D) Irradiation E) Autoclaving

75)

Please select the CORRECT statement regarding autoclaving and freezing.

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A) Autoclaving kills any microbes in a sample, sterilizing it; freezing inhibits the growth of microbes in a sample but may not kill all of them. B) Autoclavinginhibits the growth of microbes in a sample but some may survive; freezing kills any microbes in a sample, sterilizing it. C) Autoclaving involves the use of heat at greater than 100 oC while freezing involves the use of temperatures between 4 oC and 7 oC. D) Autoclaving kills most microbes but endospores can withstand the treatment; freezing kills all microbes, and also destroys endospores. E) Autoclaving causes plasmolysis in bacterial cells, inhibiting their growth; freezing causes ice crystal formation in cells, killing them.

76) From a microbiology and health standpoint, what is the role of nitrates and nitrites in preserving meat? A) They inhibit the gemination of Clostridium botulinum endospores. B) They react with the protein myoglobin in the meat, giving it a red color. C) They create a hypertonic environment, preventing the growth of pathogens on the meat. D) They are converted to nitrosamines, which are effective at eliminating all pathogens, including prions. E) They create ice crystals in the cytoplasm of Clostrium botulinum cells, killing them.

SECTION BREAK. Answer all the part questions. 77) Jasmine's boyfriend Paul has a large boil on his back. The boil is very painful to touch, and is surrounded by an area of redness that is warm to the touch. Jasmine tells you that she and Paul have decided that Jasmine will "pop" the boil later that evening when they are both home from school. You ask Jasmine what she plans to use to open the boil and she tells you she has a knife with a sharp point that she will use, and that she will wash it well with dishwashing liquid before she uses it.

77.1) You tell Jasmine that it is important that she use a sterile instrument to pierce Paul's boil. Jasmine does not know what "sterile" means or why she needs to use something sterile for her "boil surgery", so you explain. Select the best answer.

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A) A sterile instrument is free of all most pathogens but not environmental organisms. Jasmine needs to use a sterile blade because it will come into contact with Paul's tissues, and is thus a semi-critical instrument. B) A sterile instrument is free of most microbes. Jasmine needs to use a sterile blade because it will come into contact with Paul's tissues, and is a critical instrument, although the risk for infection is low. C) A sterile instrument comes in a sealed pack and is returned to that before its next use. Jasmine needs to use a sterile blade because it will come into contact with Paul's tissues, and is thus a critical instrument. D) A sterile instrument is free of all microbes,endospores, and viruses. Jasmine needs to use a sterile blade because it will come into contact with Paul's tissues, and is thus a critical instrument. E) The only known sterile instruments are hypodermic syringes, so Jasmine should use that to pop Paul's boil. Syringes are non-critical instruments because they make small wounds.

77.2) Jasmine tells you she plans to wash her hands with soap and water before working on Paul's boil, to get rid of all the bacteria on her skin and prevent the possibility of Paul getting an infection. You tell her A) that washing and scrubbing with soap will be fine because the soap will destroy absolutely all of the bacteria on Jasmine's hands, whether pathogenic or normal microbiota. B) that washing and scrubbing with soap is generally sufficient to control microbes in routine situations but that soap itself does not destroy many organisms. Jasmine should try to get some sterile gloves.  C) the likely problem is not going to be the bacteria on Jasmine's hands but those on Paul's back. She doesn't need to wash her hands but she should wash Paul's back before she works on his boil. D) that people who are shower regularly are clean and don't have any bacteria on them. Jasmine doesn't need to bother with trying to wash any bacteria off her hands because there won't be any if she showered that day. E) that people have so many bacteria on their skin, it is impossible to remove them. Even washing with soap won't remove any bacteria because they exist in biofilmson the skin. You tell Jasmine that the bacteria are normal microbiota and are harmless.

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77.3) You tell Jasmine that there are various ways that she can in fact sterilize the knife she plans to use. Which of the following is unlikely to be available to Jasmine for sterilizing her knife in her home? A) Household bleach, used at a 1:100 dilution. B) Heating the knife in a flame, such as that on a gas stove. C) Irradiating the knife with gamma rays. D) Cleaning the knife with rubbing alcohol from the pharmacy. E) Heating the knife to a high temperature in the oven.

77.4) At the end of your conversation with Jasmine, you tell her that the best course of action for her and Paul is to go to the clinic and have the boil treated there. A boil is a serious infection and the risks of trying to treat it at home are just too great. ⊚ ⊚

true false

78) You go hiking with some friends in a nearby national park. The weather is cool when you set out but it quickly becomes very warm. Neither you nor your friends are carrying enough water. Eventually you find a stream and because you are so thirsty, you drink from it. About a week later you start to feel unwell. You have vomiting, abdominal cramps, and explosive diarrhea (loud, severe diarrhea). Your stool seems kind of oily and is difficult to flush away. You tell your RN brother about your signs and symptoms, and he tells you he thinks you may have giardiasis, a gastrointestinal infection caused by the protozoan Giardia lamblia.

78.1) Your brother tells you that most likely you ingested Giardiacysts that were in the stream water. He says you should have treated the water before you drank it. Which of the following would NOT have been a possible way for you to do this, as a hiker? A) Boiling the water. B) Using a portable hiker's filter. C) Using commercial water-purifying tablets (iodine). D) Using pasteurization. E) None of the choices would be possible for a hiker.

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78.2)

Which of the following statements is FALSE regarding Giardia?

A) It contains 80S ribosomes. B) It is found in fresh water. C) It has a phospholipidcytoplasmic membrane. D) It has a peptidoglycan cell wall. E) It's DNA is contained within a membrane.

78.3) You ask your brother which method of eliminating microbes is the best in general. He tells you that there is no one perfect method and that various factors must be taken into account when considering any antimicrobial approach. These include all of the following EXCEPT A) the type of microbes to be controlled.  B) environmental conditions such as temperature. C) whether a potential infection can be easily treated. D) situational considerations (is a method practical for the situation?).  E) the number of microbes to be controlled.

78.4) Your brother goes on to explain the concept of decimal reduction (D-value) time to you. To illustrate his point, he tells you that if the D-value for Giardiawas 3 minutes and the starting number of cells was 10 4, the time it would take to eliminate allof the Giardia cells would be A) 15 minutes. B) 3 minutes. C) 10 minutes. D) 9 minutes. E) 12 minutes.

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79) A patient who had recently undergone abdominal liposuction developed a bacterial infection in the wound. A sample was takenand was cultured on Lowenstein-Jensen (LJ) medium. This medium contains penicillin and nalidixic acid to inhibit the growth of Grampositive and Gram-negative bacteria, as well as malachite green, which inhibits most other types of bacteria. After four weeks of incubation, colonies grew and were identified as Mycobacterium chelonae. An investigation was carried out at the facility where the liposuction was carried out to identify the source of the infection. It was found that other than the physician, none of the workers in the facility waslicensed medical personnel. The staff weretrained to clean the equipment used, but there were no written protocols for reusable equipment, or logs of sterilization procedures such as autoclaving. When autoclaving was performed, no biological indicators were used. There were no written infection control policies. Staff mixed leftover solutions of povidone iodine and placed the mixtures in larger containers. Alcohol-soaked cotton balls used for wiping multiuse vials were kept in large, multiuse containers. Single-use 70% alcohol prep pads were not used to clean the tops of the vials. The liposuction equipment was flushed with 70% isopropyl alcohol solution from an open, non-sterile bottle. Laboratory testing of surfaces, equipment, solutions and materials did not yield M. chelonae and it was concluded that the patient’s case was an isolated one. However, this organism can take up to five months to culture because it is acid-fast and has a generation time of 15-20 hours. The physician was advised to put controlto put cleaning, disinfection and sterilization policies and procedures in place and to educate the staff in basic infection control methods. Source and adapted from: Kim, M.J. and Mascola, L. 2010. Mycobacterium chelonae Wound Infection after Liposuction. Emerging Infectious Diseases 16 (7): 1173-1174. DOI: 10.3201/eid1607.090156

79.1)

How would you classify LJ medium, given the information in this article?

A) Selective B) Differential C) Aerobic D) Acidic E) Selective AND differential

79.2)

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Mycobacterium chelonae has a generation time of 15 - 20 hours. This means that

A) it takes 15 - 20 hours for a population of this organism to double. B) it takes 15 - 20 hours to eliminate this organism from a surface. C) it takes 15 - 20 hours for a single cell to become a large population. D) 90% of a population of these cells can be killed in 15 - 20 hours. E) this organism will be killed by 15 - 20 hours in an autoclave.

79.3) Which of the following best describes the use and purpose of Geobacillus strearothermophilus a biological indicator? A) Endospores of Geobacillus stearothermophilus are included with an item in the autoclave. After autoclaving, the endospores are added to a growth medium. If the medium changes color during incubation, microbial growth has occurred, indicating an unsuccessful process. B) Geobacillus stearothermophiluscells are included with an item in the autoclave. After autoclaving, the cells are added to a growth medium. If the medium changes color during incubation, microbial growth has occurred, indicating an unsuccessful process. C) Endospores of Geobacillus stearothermophilus are included with an item in the autoclave. After autoclaving, the endospores are added to a growth medium. If the medium changes color during incubation, microbial growth has not occurred, indicating a successful process. D) Geobacillus stearothermophiluscells are included with an item in the autoclave. After autoclaving, the cells are added to a growth medium. If the medium changes color during incubation, microbial growth has not occurred, indicating a successful process. E) Endospores of Bacillus subtilis are included with an item in the autoclave. After autoclaving, the endospores are added to a growth medium. If the medium changes color during incubation, microbial growth has occurred, indicating an unsuccessful process.

79.4)

Select the INCORRECT statement regarding alcohol and iodine.

A) Alcohols denature proteins such as enzymes and damage lipid membranes. B) 99% alcohol is a more effective disinfectant than 70% alcohol. C) Iodine tincture is an effective alcohol-based disinfectant. D) Alcohol can be used on both skin and medical instruments. E) Iodine is a highly reactive oxidizing agent.

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79.5) Which of the following statements regarding the procedures used by the staff of the facility in this case is TRUE? A) They used 70% alcohol to flush the liposuction equipment. B) They included a biological indicator when autoclaving equipment. C) They used alocohol pads to wipe the lids of multiuse vials. D) They used single-dose povidine iodine prep pads to wipe vials. E) They used gloves, gowns and masks when working with clients.

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Answer Key Test name: Chap 05_10e 1) FALSE 2) FALSE 3) TRUE 4) TRUE 5) FALSE 6) TRUE 7) FALSE 8) FALSE 9) FALSE 10) TRUE 11) FALSE 12) FALSE 13) TRUE 14) FALSE 15) FALSE 16) B 17) C 18) A 19) B 20) B 21) C 22) B 23) B 24) E 25) A 26) C Version 1

27) B 28) D D is defined as the time required to kill 90% of the total population. After the first D, 10% or 109 cells would be left. After the second D 108 cells would be left. Each D reduces the cell number by one order of magnitude. To reduce by 10 orders of magnitude to 100 = 1, it would take 10 D. 29) A 30) E 31) A 32) C 33) B 34) A 35) C 36) C 37) E 38) A 39) C 40) D 41) B 42) B 43) A 44) B 45) B 46) B 47) A 48) E 49) D 50) B 51) A Version 1

52) A 53) A 54) D 55) E 56) A 57) A 58) A 59) E 60) C 61) D 62) B 63) B 64) E 65) A 66) A 67) A 68) A 69) A 70) A 71) A 72) A 73) A 74) A 75) A 76) A 77) Section Break 77.1) D 77.2) B 77.3) C 77.4) TRUE Version 1

78) Section Break 78.1) D 78.2) D 78.3) C 78.4) A 79) Section Break 79.1) A 79.2) A 79.3) A 79.4) B 79.5) A

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CHAPTER 6 TRUE/FALSE - Write 'T' if the statement is true and 'F' if the statement is false. 1) The change in free energy of a reaction varies. ⊚ ⊚

Both glycolysis and the pentose phosphate pathway oxidize glucose to pyruvate. ⊚ ⊚

true false

Enzymes are changed by the reaction as they raise the activation energy. ⊚ ⊚

true false

4) Competitive inhibition usually involves both substrate and inhibitor competing for binding at the allosteric site. ⊚ ⊚

true false

5) The production of ATP via the electron transport system, in either eukaryotes or prokaryotes, requires the use of a membrane. ⊚ ⊚

true false

6) The TCA cycle must "turn twice" in order to complete the oxidation of one glucose molecule. ⊚ ⊚

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true false

7) The terminal electron acceptor in aerobic respiration is water, which is broken down to hydrogen and oxygen. ⊚ ⊚

true false

8) In fermentation, the only ATP produced was during glycolysis and the fermentation reactions usually result in converting NADH to NAD. ⊚ true ⊚ false

10)

2S and NH

⊚ ⊚

true false

3 may be used by some prokaryotes as energy sources.

The Calvin cycle produces six ATP for every six turns of the cycle. ⊚ true ⊚ false

11) In Gram-negative bacteria, the electron transport chain involved in respiration is located in the lipopolysaccharide layer. ⊚ ⊚

true false

12) Cells must secrete enzymes that degrade macromolecules into their subunits before they can use these compounds. ⊚ ⊚

13)

true false

Purines and pyrimidines are produced by the same process.

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⊚ ⊚

true false

MULTIPLE CHOICE - Choose the one alternative that best completes the statement or answers the question. 14) Experiments designed by ______ suggested that living cells caused the fermentation of sugar to produce alcohol. A) Pasteur B) Koch C) Wohler D) Fleming E) Jenner

15) Studies done by Buchner showed that ground-up yeast cells were able to convert sugar to alcohol. The components of the mixture that were responsible for this transformation were A) DNA molecules. B) enzymes. C) lipids. D) carbohydrates. E) phospholipids.

16)

Which of the statements aboutcatabolism and anabolism isTRUE? A) They refer only to the reactions dealing involved in the metabolism of lipids. B) The intermediates of catabolism serve as products inanabolism. C) The energy gathered during catabolismis used during anabolism. D) They refer only to the reactions involvedin carbohydrate synthesis. E) The energy gathered during anabolismis used during catabolism.

17)

The general term used to describe the anabolic and catabolic reactions in a cell is

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