Name: ___________________________ Class: _________________ Date: __________
Chapter 02 1.
2.
3.
Your own scientific literacy would NOT be helpful in answering which of the following questions? a.
Should I take a cinnamon capsule every morning to help regulate my blood sugar?
b.
Should I spend the extra money to buy a particular pair of shoes that claims to help tone my leg muscles better than other athletic shoes?
c.
Will my cell phone cause me to have cancer?
d.
Which movie should I watch this weekend?
Which of the following would NOT be a situation where your own scientific literacy would be helpful in decision-making? a.
Should I send my child to a school that requires my child be vaccinated according to the vaccination schedule recommended by the Centers for Disease Control?
b.
Should I pay to store umbilical cord blood when my baby is born?
c.
Should I vote to support a new oil pipeline through a sensitive natural area?
d.
Is the space travel in Star Wars really possible?
Which of the following statements about the process of science is accurate? a.
Science is a systematic method designed to answer questions by evaluating evidence.
b.
Science attempts to solve a problem by evaluating the plausibility of only one solution without considering other possible explanations.
c.
Science does not use evidence and data collected to advance our understanding of natural and supernatural phenomena.
d.
4.
5.
6.
Science can answer all questions regarding the human experience and personal values.
Which of the following is LEAST likely to include unchecked bias when making scientific statements? a.
political groups
b.
religious groups
c.
marketing groups
d.
peer-reviewed scientific journals
Therapeutic touch (TT) is a type of “energy” medicine that involves the practitioner moving his or her hands over the energy field of the patient, without actually touching the patient, but redirecting the energy field to heal the patient. If a researcher were to design a survey of TT practitioners and their patients to determine the validity of TT, which of the following questions would NOT be helpful in determining the validity of the survey? a.
Is the researcher a regular TT practitioner or patient?
b.
Do the survey participants have a working relationship with the researcher or were they paid to participate?
c.
Are any non-TT patients included in the survey?
d.
How old is the researcher?
Which of the following would be a positive consideration when evaluating a researcher’s expertise regarding a particular scientific claim? a.
The researcher has an ideological, political, or religious belief that will be supported by the scientific claims being made.
b.
The researcher stands to make money if others accept the claims being made.
c.
The researcher stands to gain in prestige if others accept the claims being made.
d.
7.
8.
The researcher has a PhD, MD, or at least an MS and years of experience in the field in which he or she is making a scientific claim.
An individual claims to be able to detect the presence of graves in an old cemetery by using a “dowsing” or “divining” rod. The rod is a forked twig held in front of the individual as he walks across the cemetery. The “dowser” (person who is using the dowsing rod) claims that depending on which way the twig moves (up and down or side to side) he can determine if a grave is there and the gender and age of the individual buried at that spot. Which of the following would NOT help to evaluate if the dowser is a fraud? a.
It would help to know if the dowser had any previous knowledge of the cemetery.
b.
It would help to actually dig up the site to determine if the dowser’s predictions were accurate.
c.
It would help to at least use X-rays or some other means to examine what might or might not be buried in the ground.
d.
It would help to know the dowser’s age and affiliation with other dowsers.
Therapeutic touch (TT) is a type of “energy” medicine that involves the practitioner moving his or her hands over the energy field of the patient, without actually touching the patient, to redirect the energy field and heal the patient. Which of the following would be the first concept to investigate to help evaluate the claims of TT practitioners? a.
documentable and repeatable evidence that an external energy field actually exists for humans
b.
documentable and repeatable evidence that any existing energy field can be manipulated by merely passing hands over it
c.
documentable and repeatable evidence that TT practitioners can, without seeing or touching their subjects, actually feel the energy field of a patient
d.
documentable claims by TT practitioners and their patients that the patients thought they felt better after being treated by the TT practitioner even though there was no change in their diseases
9.
10.
11.
You are reading an article written by Neil Shubin et al. regarding the pectoral fin of Tiktaalik roseae in the peer-reviewed journal Nature. Dr. Shubin is a member of the National Academy of Sciences and is employed by The University of Chicago. This article represents a __________ literature presentation of __________ research. a.
primary; basic
b.
primary; applied
c.
secondary; basic
d.
secondary; applied
You are reading an article in Discover magazine about Tiktaalik roseae, the organism thought to be the link between fish and terrestrial tetrapods. The researcher that discovered Tiktaalik was publicly funded. This article represents a __________ literature presentation of __________ research. a.
primary; basic
b.
primary; applied
c.
secondary; basic
d.
secondary; applied
Scientists working for a major cosmetics company want to determine if a new face cream can reduce the number of fine lines and wrinkles on a person's face. This is an example of a.
applied research.
b.
basic research.
c.
meta-analysis.
d.
a cohort study.
12.
13.
14.
15.
Scientists at a major university are attempting to isolate a gene that slows the degeneration of collagen in skin. This is an example of a.
applied research.
b.
basic research.
c.
meta-analysis.
d.
a case-control study.
A research team funded by federal grants is studying the coevolution of pain receptors in grasshopper mice and the neurotoxic venom of scorpions (one of their primary food sources) to determine how the mice have adapted to the venom of their prey. This is an example of __________ research. a.
basic
b.
applied
c.
pseudoscientific
d.
random
A research team funded by a pharmaceutical company is studying the adaptation of grasshopper mice to the neurotoxic venom of scorpions in an attempt to determine how the mice’s adaptation could be used as a possible solution to pain management in humans. This is an example of __________ research. a.
basic
b.
applied
c.
pseudoscientific
d.
random
The federally funded Centers for Disease Control routinely collect and evaluate data regarding communicable diseases. This information helps
researchers make recommendations regarding vaccination schedules for children and adults. This is an example of
16.
17.
18.
a.
basic research.
b.
applied research.
c.
a case-control study.
d.
a cohort study.
A pharmaceutical company conducts trials on animals and cell lines to determine the safety of a new vaccine before performing clinical trials on adult human volunteers. This is an example of a.
basic research.
b.
applied research.
c.
a case-control study.
d.
a cohort study.
Which of the following examples indicates a situation where the researcher is MOST likely to have a possible bias regarding his or her work? a.
A researcher, funded by a pharmaceutical company, is testing the clinical effectiveness and safety of a new vaccine.
b.
A researcher, funded by a public grant, is testing the clinical effectiveness and safety of a new vaccine.
c.
A federally funded researcher is working on developing a genetically engineered microbe to quickly digest oil spills.
d.
A privately funded researcher is working on developing a genetically engineered and patented microbe to quickly digest oil spills. If successful, the microbe would be marketed worldwide.
You are reading an article in National Geographic regarding the evolution of humans. This would be an example of __________ literature.
19.
20.
21.
a.
primary
b.
secondary
c.
peer-reviewed scientific journal
d.
meta-analysis
Announcing “scientific” findings in a press conference before they have been published in an established scientific journal is an example of a.
primary literature.
b.
secondary literature.
c.
neither primary nor secondary literature because it has not yet undergone peer review to be primary literature, and secondary literature follows primary literature.
d.
both primary and secondary literature because it does not need to undergo peer review to be either primary or secondary literature.
The reliability of primary scientific literature is strengthened by the __________ process, in which the work is examined by other researchers in the same field. For instance, a scientific paper examining the evolution of tetrapods would be reviewed by other evolutionary biologists and paleontologists. a.
peer-review
b.
basic research
c.
applied research
d.
random research
Scientists analyzed 62 studies and determined that a strong physician recommendation for the HPV vaccine was a positive determining factor in whether or not parents chose to vaccinate their children. This analysis of various studies is referred to as
22.
23.
a.
meta-analysis.
b.
beta-analysis.
c.
secondary study.
d.
secondary analysis.
Based on the scientific evidence presented in more than 100 peer-reviewed, published research articles that evaluated millions of children, which of the following is NOT the reason for the observed increase of autism in the United States and other countries since the 1970s? a.
There is a heightened awareness of autism in society.
b.
More schools are screening more students for autism.
c.
People are generally more willing to label a broader range of conditions within the spectrum of autism disorders.
d.
The MMR vaccine is being more broadly administered, so more children are getting autism.
A researcher noticed that as the prevalence of cell phone usage increased between the years of 1998 and 2010, so did the number of individuals diagnosed with autism. He decided that cell phone usage by expectant mothers was causing autism. Which of the following would be the first step in evaluating his assumption? a.
The researcher should develop a clearly testable and falsifiable hypothesis.
b.
The researcher should carefully design a reproducible experiment.
c.
The researcher’s experiment should include thousands of participants from all gender, socioeconomic, racial, and ethnic groups both with and without autism.
d.
The researcher should use a small sample size (20 participants) of autistic children and their mothers to support the hypothesis.
24.
25.
The graph below shows which of the following?
a.
There is a strong correlation between the sale/consumption of organic food and the number of individuals diagnosed with autism between 1998 and 2007.
b.
The increased consumption of organic food has led to an increase in the rate of autism between 1998 and 2007.
c.
Consuming organic food causes autism.
d.
There is strong evidence that a cause-effect relationship exists between the consumption of organic food and the development of autism.
Thomas’s foot began to swell after he was stung by a scorpion. Thomas’s friend said his mom had an old, trusted herbal poultice remedy that would absorb the venom from the foot, reduce the swelling, and heal the foot. Thomas allowed his friend to place the herbal poultice on his foot before going to bed that night, and the swelling was gone in the morning. Which of the following can be concluded about the herbal poultice remedy?
26.
27.
a.
The poultice definitely worked because the swelling went down.
b.
The poultice definitely did not cause the swelling to go down.
c.
It is very likely that the poultice caused the swelling to go down.
d.
There is not anything that can be concluded about the effectiveness of the poultice remedy.
When Lori was diagnosed with breast cancer, the doctor recommended a lumpectomy followed by radiation therapy. Lori underwent the prescribed treatment recommended by the doctor. However, she also continued to eat lots of fruits and vegetables, walk three miles every day, and practice daily yoga. Within about three months, Lori was cancer-free. Afterward, Lori told everyone that her healthy lifestyle had helped to cure her. Is this conclusion reasonable given the circumstances? a.
No, a healthy diet and exercise regimen can never help cure cancer.
b.
No, there are too many confounding factors to know exactly what happened.
c.
Yes, the healthy diet and exercise regimen definitely helped to cure her.
d.
Yes, this evidence very strongly supports the hypothesis that a healthy diet and exercise regimen probably helped to cure her.
The fact that the onset of autism symptoms typically occurs at about the same age children receive many of their vaccinations, including the MMR, is an example of an observed a.
correlation but not necessarily evidence of a cause-effect relationship.
b.
correlation and strong evidence of a cause-effect relationship.
c.
cause-effect relationship supported by empirical evidence.
d.
cause-effect relationship but not necessarily a correlation.
28.
29.
30.
Which of the following is NOT a reason to scientifically evaluate the plausibility of claims made by a psychic who states that a missing child is alive and located in a particular area of the countryside months after the child went missing? a.
Precious time to search for the child could be lost.
b.
Manpower could be wasted looking in a location when there is no scientific evidence indicating the child might be there.
c.
It could cause additional and unnecessary grief when the new hopes and expectations of the parents are dashed.
d.
There is anecdotal evidence suggesting that psychics can predict the location of missing children.
Rick has high blood pressure and decides to try an herbal supplement recommended by his friend. Which of the following questions should Rick ask first to scientifically evaluate his friend’s recommendation before he begins taking the herbal supplement? a.
Has this herbal supplement been studied in a clinical trial by trained medical professionals?
b.
If this supplement was studied, who paid for the study?
c.
If this supplement was studied, how many people were included as patients in the study?
d.
What are the credentials of the team investigating the supplement?
Although it seems contradictory, real science does not intend to “prove” a hypothesis to be true. This is because a.
all true hypotheses will be rejected by the scientific method because they can be proven false.
b.
future experiments or discoveries may provide data that refute the hypothesis.
c.
science is a human endeavor, and like all human endeavors, it is limited by human understanding.
d.
the scientific method is limited to examination of the natural world.
31.
32.
33.
Developing a scientific understanding of a natural phenomenon typically begins by a.
observing a quantifiable natural phenomena.
b.
proving an answer.
c.
making a prediction.
d.
testing a hypothesis.
Sue has twin baby boys and is trying to decide whether to have them vaccinated against chicken pox or to take them to a “chicken pox party” where they can be naturally exposed to other children who currently have chicken pox. Which of the following would be the first relevant question for Sue to research before making her decision? a.
Are there any peer-reviewed, scientific studies of observable and quantifiable claims regarding the chicken pox vaccine or chicken pox parties?
b.
Do any relevant studies make testable and falsifiable predictions related to a clearly stated hypothesis?
c.
Are the relevant studies well designed and described with large sample sizes and minimization of bias, and have the results been reproducible?
d.
Are there a lot of parents on the Internet endorsing the chicken pox parties?
When determining whether a claim about a new cleansing juice diet is scientific or pseudoscientific, which of the following is NOT a helpful question to ask yourself? a.
What are the credentials and possible bias or agenda of the person(s) making the claim?
b.
Has the claim been published in a peer-reviewed, reputable scientific journal?
34.
35.
c.
Does the scientific study purporting to support the claim meet the standards of the scientific method?
d.
Are there a lot of people, including celebrities, endorsing the product as a healthy weight-loss method?
A popular post on the Internet states that hugs “transfer energy” between participants, giving them an “emotional lift.” Which of the following is a scientific approach to evaluating the claim of “energy transfer” during hugs? The hypothesis for the experiment would be as follows: if one person hugs another, the person receiving the hug will have more measurable energy after the hug. a.
First, develop a method of physically measuring the amount of energy available in a human being. Divide hundreds of subjects randomly into two groups, huggers and non-huggers. The available energy in the individuals of each group would be measured, the individuals would then hug (or not), and then the energy levels are measured again. The experimenter should not know which group is the hugging or nonhugging group to avoid expectation bias. The experiment should be repeated numerous times before analyzing the data.
b.
The researcher would need some people willing to hug someone else and fill out a survey stating how they felt before and after the hug. This should be repeated several times.
c.
The researcher would need some people willing to keep a daily log of how they feel during the day, how many hugs they get, and which days they feel the best at the end of the day.
d.
The researcher would need some people willing to complete a scientifically developed life history hugging survey. Through the survey, participants will document their own life histories of hugs (average number of hugs per day and how long they lasted) and emotional well-being. Once the survey is completed, the researcher will collate and evaluate the evidence. He or she should repeat this with a few different groups of people.
In the fall of 2012, a veterinarian from Texas issued a press release stating that her team of scientists had completed a five-year DNA study confirming the existence of “Sasquatch” or “Bigfoot.” Which of the following statements, if true, would lend support to her claims?
36.
37.
a.
She released her findings in a press conference prior to any peer review of her findings.
b.
There are no corresponding lines of documented physical evidence (fossil record, historic record, undisputed clear picture or video, or evidence that the environment could support a breeding population of large primates in the areas where they have been reported) to support her claims.
c.
The paper is published in an online source that consists of one issue with only this one paper (the full paper is for sale), and this new online publication is owned by the veterinarian.
d.
She consulted experts in the field of human genomics and made her DNA samples available to them for analysis.
Announcing “scientific” findings in a press conference before they have been published in an established scientific journal suggests a.
there may be reason to question the validity of the results or conclusions.
b.
that the results were too ground-breaking to wait for or need peer review.
c.
there is no reason to question the validity of the results.
d.
that the media has scientifically determined the results to be valid and repeatable.
A scientific paper that combines results from several cohort studies and a case-control study would be considered a(n) __________-analysis. a.
meta
b.
beta
c.
omega
d.
pseudo
38.
39.
40.
Observational studies that follow a particular group of individuals over a certain time period are __________ studies. a.
case-control
b.
meta-analysis
c.
beta-analysis
d.
cohort
If the Centers for Disease Control’s recommended vaccination schedule is delayed, the children who do not receive their vaccines on schedule a.
are just as well protected from diseases as they would be if they were on schedule.
b.
experience a decreased risk of contracting disease than they would experience if they were on schedule.
c.
experience no change in protection from diseases as they would experience if they were ahead of schedule.
d.
experience an increased risk of disease.
Which of the following situations might present a logical reason for accepting a scientific claim made by a person who did not have appropriate credentials for making that claim? a.
The claim could be supported by other nonbiased and credentialed scientists who have conducted similar research and arrived at the same conclusion, and the claim has been peer-reviewed.
b.
The claim could be supported by many other noncredentialled people who share the same ideas.
c.
The claim could be supported because the person really, truly believes what he or she is saying is accurate from his or her own personal experiences.
d.
The claim could be supported because certain celebrities have endorsed the idea presented by this particular researcher.
41.
42.
43.
Scientific studies that compare patients with a disease to those without the disease are referred to as a.
case-control studies.
b.
clinical trials.
c.
cohort studies.
d.
in vitro studies.
Which of the following would NOT be a reason for a peer-reviewed paper to be retracted by its publisher as untrue or inaccurate? a.
The author has made a clear error in the scientific process.
b.
It has been shown that the author plagiarized someone else’s work.
c.
It has been discovered that the author violated ethical guidelines or was involved in other scientific misconduct.
d.
Other researchers have published work that appears to contradict the paper in question.
A scientist publishes a paper in a peer-reviewed journal; this paper is later retracted. Which of the following (if found to be true) is NOT a legitimate reason for the retraction? a.
The study involved only 12 participants, but sweeping conclusions were made by the author. These participants were not randomly sampled; they were picked specifically for their symptoms. Furthermore, there was no control group.
b.
The findings could not be replicated, and there were many peerreviewed studies, including millions of participants that found no evidence for the claims of the original paper.
c.
The primary author of the paper received large amounts of money as a paid expert for lawyers who were suing companies based on the author’s claim. The author would also benefit financially in other ways, such as patents on alternative products.
d.
44.
45.
Although the findings were not replicated by other researchers, some studies indicated that the original paper might suggest a valid line of reasoning and warrants further investigation.
You discover that a holistic treatment called “ear candling” involves putting the end of a wax-coated cloth cone (a “candle”) into your ear and lighting it on fire, letting it burn to within about four inches of your face, and then repeating with a new candle. This process is supposed to remove tension, anxiety, and stress from your body. Which of the following statements or questions would be most helpful in scientifically evaluating these claims? a.
Your great-aunt used ear candling on all of her children and grandchildren, and they have all lived long and healthy lives.
b.
Have there been any studies that measured the feelings of well-being in individuals before and after ear candling?
c.
Ear candling has been used for centuries by many different cultures to cure earaches, reduce stress, and promote general well-being.
d.
Have there been any reproducible, peer-reviewed studies that compared ear candling in individuals who have ear infections with those who do not have ear infections?
According to the Centers for Disease Control (CDC), by the end of September 2014, roughly 8,000 cases of whooping cough had been reported in California for that year; more than 250 patients (mostly infants and young children) were hospitalized, with 58 of them requiring intensive care. Several other childhood diseases that were once common but then eradicated through high vaccination rates have returned since the antivaccination movement grew in the 1990s. The epidemiological data collected by the CDC indicates this resurgence of childhood diseases is most likely the result of a.
reduced herd/community immunity.
b.
reduced vaccine effectiveness.
c.
increased virulence of the pathogens causing these diseases.
d.
simply the increased number of people present in the United States.
46.
The figure below, based on data collected by The National Institute of Allergy and Infectious Diseases, graphically illustrates that as
47.
a.
increasingly more individuals in a community are vaccinated against a particular pathogen, future outbreaks of the disease are limited to fewer individuals because fewer people will become infected and then pass it on.
b.
individuals in a community become ill, increasingly more individuals either become ill or think they are becoming ill as they find out about the illness from friends, family, and the media.
c.
increasingly more individuals in a community are vaccinated against a particular pathogen, future outbreaks of the disease are limited to fewer individuals because fewer people think they can become ill. Just the idea of vaccines protecting from disease will make people think they are protected so they will not experience any symptoms.
d.
a population of individuals is infected with a particular pathogen, more and more people will become infected. This is beneficial because everyone will always survive, and their offspring will be immune to any future infections.
The figure below, based on data collected by The National Institute of Allergy and Infectious Diseases, graphically illustrates that a disease is less likely to spread to vulnerable members of a population if most of the population is immunized against the disease. This phenomenon occurs because
a.
when fewer individuals in the population are likely to become infected, fewer people are able to spread the disease, and the vulnerable members of the population are less likely to come in contact with contagious individuals.
48.
b.
if more individuals in the population become infected, fewer people are able to spread the disease, and the vulnerable members of the population are less likely to come in contact with contagious individuals.
c.
if more individuals in the population become infected, more people are able to spread the disease, and the vulnerable members of the population are less likely to come in contact with contagious individuals.
d.
when none of the population is immune to the disease, no one will contract the disease and therefore pass it on to the vulnerable members of the population.
In 1999, the United Kingdom began a meningitis vaccination program for children up to age 18. The graph below shows that post vaccination program, the number of adult meningitis cases is
a.
strongly correlated with the number of childhood meningitis cases; this appears to be related to the increased vaccination rates in children.
49.
b.
not correlated with the number of childhood meningitis cases; there appears to be no relationship to the increased vaccination rates in children.
c.
weakly correlated with the number of childhood meningitis cases; there appears to be no relationship to the increased vaccination rates in children.
d.
strongly but negatively correlated with the number of childhood meningitis cases; this is caused by the increased vaccination rates in children.
The graph below shows that after the childhood vaccination program was initiated in the United Kingdom in 1999, the annual number of meningitis cases in children
a.
decreased to nearly zero by 2004, as did the meningitis rate for adults.
b.
increased to over 700 in 1999 before slowly decreasing in 2000, as did the meningitis rate for adults.
50.
c.
did not decrease or increase; there was also no change in the meningitis rate for adults.
d.
decreased to zero by 2000, as did the meningitis rate for adults.
CDC’s HPV Vaccine Impact Monitoring Project evaluated data from over 10,000 biopsy specimens collected between 2008 and 2014. The proportion of cervical precancers due to HPV types 16 and 18 decreased from 55 percent to 33 percent in women ages 18–39 who had been vaccinated with the HPV vaccine. Additionally, precancers among unvaccinated women declined due to HPV-16/18. This decline is likely due to __________ immunity, which occurs when a significant proportion of a population has developed immunity to a disease. a.
individual
b.
herd
c.
natural
d.
vaccination
51.
Why would it be beneficial for you to be scientifically literate when choosing whether to purchase expensive workout apparel that claims to reduce muscle fatigue and promote circulation better than other brands of apparel?
52.
What is a first step an individual should take when beginning to assess a “scientific” claim made by another person?
53.
A large biotech company would like to market a microbe that will help clean up oil spills in the ocean by actually consuming and detoxifying the oil. Would this research be basic or applied? Explain your answer.
54.
Cheryl searches the Internet for information regarding the use of a particular herbal supplement because she has heard claims that it will help her safely build muscle while losing fat. During her search she comes across a site that claims to have evidence to support those claims. What questions should Cheryl ask herself as she peruses the site?
55.
Evaluate the following paragraph and determine whether the treatment method is most likely based on science or pseudoscience. Provide a brief explanation of your answer. “The symptoms of your cold are similar to those of mercury poisoning, so mercury should be the remedy you use. Of course, you should dilute it by using one part mercury to one trillion parts of pure water. This one allnatural remedy will treat all of your symptoms. You can trust this method because it is a very widely used system of medicine in the world, and its popularity is growing. Babies and pregnant women can use this method with no adverse effects, and it works in harmony with your immune system.”
56.
The graph below illustrates the predicted number of meningitis cases with or without herd immunity after the initiation of the meningitis vaccination program in the United Kingdom in 1999. Write a short paragraph comparing the observed number of cases to the predicted number of cases. Assess the predictive value of the model used to generate the graph and how this relates to the prediction of the number of cases that would exist without herd immunity.
57.
How does the HPV vaccine stimulate immunity in an individual human? Be sure to accurately include the following terms: antibodies, infectious organism, immune system, vaccine, virus.
58.
Your best friend, Joe, is selling a new apparatus he claims will generate “alkaline water” (having pH levels greater than 8) that you can drink in your own home. Joe also claims that drinking “alkaline water” will decrease your risk of getting cancer, lower your blood pressure, lower your blood sugar, improve your digestion, balance your body’s energy, and generate a sense of well-being. You can own your own machine for just $2,500 plus shipping and handling! Which of Joe’s claims are scientific and which are pseudoscientific? Include rationale, such as which claims could be tested in a lab, and describe why it is important to question Joe’s claims.
59.
In 2015 in the United States, the dietary supplements industry, including herbal remedies and energy drinks, grossed somewhere between 12 and 24 billion dollars in sales. The FDA regulates the safety and manufacture of conventional, pharmaceutical drugs before they are marketed to consumers. However, the companies that produce dietary supplements are responsible for evaluating the safety and purity of their own products before these are marketed to consumers. The FDA is responsible only for taking action against any adulterated or misbranded dietary supplement product after it reaches the market and consumers. The FDA will also issue warnings about a product after adverse reactions have been reported. Your friend, Vivian, is selling a fruit juice that contains a “secret, proprietary blend” of herbal ingredients. Vivian tells you that this fruit juice cured her dad’s migraine headaches, so you should use it to cure your migraines and to quit taking the medicine prescribed by your doctor. Write at least three steps you should take before you decide to follow Vivian’s advice about the juice.
60.
Why is it necessary to receive a new flu vaccine each year?
61.
You see a blog post on social media stating that this year’s flu vaccine is not very effective against the current strains of flu. The post urges readers to avoid the vaccine because it might actually give you the flu. What steps should you take and what types of information should you consider when evaluating this statement before deciding whether to get vaccinated with this year’s flu vaccine? Be sure to include examples of primary versus secondary literature.
62.
Between 1997 and 2007, mobile cell phone subscriptions have steadily increased from 18 users per 100 inhabitants to roughly 97 users per 100 inhabitants in developed countries. During this same time, diagnosed cases of autism have also steadily increased from around 50,000 to 250,000. Your friend decides that cell phones must cause autism. Briefly describe what your response would be to your friend’s conclusion, indicating any possible relationship(s) that may or may not exist.
63.
Medical researchers at the University of Sydney in Australia examined data from several cohort studies and several case-control studies regarding links between vaccines and autism. Overall, these studies included more than 1.25 million children from four different countries and vaccines for five different diseases. The paper concluded that there is no link between vaccines and autism. This work was published in the peer-reviewed journal Vaccine, and the researchers at the University of Sydney had no conflict of interest with the vaccines or the treatment of autistic children. Briefly describe this type of study and research (including if it is basic or applied research) and evaluate the strength of the researchers’ claim that no link exists between vaccines and autism. List four lines of evidence to support your assertion.
64.
A friend tells you that vaccines, in general, are not safe and that no one is keeping track of the side effects and dangers associated with vaccines. Your friend has decided that he will not be vaccinated and will not have any of his children vaccinated. You want to encourage your friend to reconsider his views, so you share with him that there are actually various organizations continually testing and evaluating vaccines for effectiveness, safety, and side effects. Summarize three ways this occurs.
65.
Which of the following texts are examples of primary literature and which are examples of secondary literature? a.
primary
b.
secondary __ 1. Biology Now 3e, your textbook __ 2. review articles found in peer-reviewed scientific journals __ 3. Journal of the American Medical Association, a peer-reviewed scientific journal __ 4. Science, a peer-reviewed scientific journal __ 5. National Geographic, a popular magazine about science and the world __ 6. Discover, a popular magazine about science __ 7. Popular Science, a popular magazine about science
__ 8. The Proceedings of the 15th Annual Meeting of the Society for Integrative and Comparative Biology, a publication of peerreviewed presentations at a professional meeting
66.
Indicate which of the following examples are most likely “real science” and which are most likely “pseudoscience.” a.
real science
b.
pseudoscience __ 1. This herbal remedy must work because people have used it for thousands of years and it always makes them feel better. __ 2. Facilitated Communication works only when everyone in the room believes it will work. __ 3. When this herbal remedy was given to 1,500 individuals who suffer from high blood pressure, 75 percent of those individuals experienced a decrease in their blood pressure. This was compared to a decrease in the blood pressure of 35 percent of the 1,500 individuals who were given the placebo. Another 1,500 participants in the study were given the standard blood pressure medication, and 73 percent of those individuals experienced a reduction in their blood pressure. __ 4. Dr. Simoncini insists on his website that cancers are actually fungal infections that can be cured by increasing the pH of the human body. He will gladly cure your cancer for 500,000 euros. __ 5. A researcher at The Baylor College of Medicine publishes peerreviewed research indicating that immunotherapy can help fight certain types of cancer. __ 6. The Journal of the American Medical Association publishes a peer-reviewed article showing a link between certain strains of the Human Papilloma Virus (HPV) and cancers of the urogenital tracts in both females and males.
Answer Key Chapter 02
1. Answer:
D
2. Answer:
D
3. Answer:
A
4. Answer:
D
5. Answer:
D
6. Answer:
D
7. Answer:
D
8. Answer:
A
9. Answer:
A
10. Answer:
C
11. Answer:
A
12. Answer:
B
13. Answer:
A
14. Answer:
B
15. Answer:
B
16. Answer:
B
17. Answer:
D
18. Answer:
B
19. Answer:
C
20. Answer:
A
21. Answer:
A
22. Answer:
D
23. Answer:
A
24. Answer:
A
25. Answer:
D
26. Answer:
B
27. Answer:
A
28. Answer:
D
29. Answer:
A
30. Answer:
B
31. Answer:
A
32. Answer:
A
33. Answer:
D
34. Answer:
A
35. Answer:
D
36. Answer:
A
37. Answer:
A
38. Answer:
D
39. Answer:
D
40. Answer:
A
41. Answer:
A
42. Answer:
D
43. Answer:
D
44. Answer:
D
45. Answer:
A
46. Answer:
A
47. Answer:
A
48. Answer:
A
49. Answer:
A
50. Answer:
B
51. Answer:
It would benefit me to understand how to evaluate the claims to “reduce muscle fatigue” and “promote circulation” because there may be no scientific evidence supporting the claim that the more expensive clothes do this or are any better at doing this than a less expensive brand. I would waste my money if the less expensive brand does these things just as well as the more expensive brand.
52. Answer:
A first step toward assessing the strength of a person’s scientific claim is to check her credentials. Does the individual have a degree, such as a PhD or MD, and is her degree in a field directly related to the area in which she is asserting expertise? It would be suspicious if the individual has a PhD in business and is making health claims about a new cancer drug.
53. Answer:
This would be applied research because the scientific knowledge is being applied to a human/environmental issue with potential commercial application. There is the potential for bias on the part of the researcher if he or she stands to benefit either financially or professionally from the findings.
54. Answer:
What evidence does the site share? If there was a study, where was the study conducted? Who paid for the study? Is there a description of the study readily available for me to read? Most important, was the study published in a peer-reviewed scientific journal or in primary literature? Additionally, she would want to ask if the site is trying to sell a product.
55. Answer:
This treatment is most likely based on pseudoscience. The statement uses scientific-sounding terminology without applying the scientific method/process. Although it would be possible to design an experiment to test a hypothesis with clearly measurable, testable, and falsifiable predictions, no such experiment has been mentioned, and no results have been presented. Overstated conclusions are presented as fact. Just because a method is “all natural,” “widely used,” or “growing in popularity” does not mean that it is effective or has been scientifically evaluated and peer-reviewed.
56. Answer:
Comparing the number of predicted cases with herd immunity to that of observed cases demonstrates a very close correlation between the two data sets. Assuming that the vaccination program successfully generated herd immunity in the population, we can deduce that the model used to make the predictions is accurate. If the model can accurately predict the number of “meningitis cases with herd immunity,” then it can likely also accurately predict the number of “meningitis cases without herd immunity.”
57. Answer:
A vaccine containing proteins found on the surface of the HPV virus is injected into the muscle of an individual. When the individual's immune system encounters these proteins, the immune system will begin to produce antibodies that recognize these proteins. If the individual is subsequently exposed to the HPV virus, his or her immune system is already primed with antibodies to attack the invading virus.
58. Answer:
First of all, the pH of the water produced by the machine could be tested to determine the actual pH; this would be a testable scientific claim. Another claim that could be tested is that it will lower your blood pressure and blood sugar. The claim that it will lower your risk of getting cancer would require more time to test, but could possibly be tested. If you wanted to test how much it improves your digestion, you would need to determine how to measure that improvement. All of these testable things would also require testing on many people to support or not support Joe’s claims. Joe’s claims that it will “balance your body’s energy and generate a sense of well-being” are vague and nondescript claims that would be extremely difficult if not impossible to test, so these are probably pseudoscientific claims. It is important to question or test Joe’s claims because the machine is expensive, and even if it really does make “alkaline water,” it might not actually be good for you.
59. Answer:
1) Try to discover what is in the “secret, proprietary blend” because you might be allergic to one of the ingredients. 2) Look up the product to see if there are any health warnings (like from the FDA) that have been issued regarding the product or its ingredients. 3) Consult secondary literature to gain a basic understanding of the product and any claims associated with it. 4) Consult primary literature to discover if there are any peerreviewed scientific studies investigating the effectiveness and safety of the product and its ingredients. 5) Check to see who conducted and paid for any published studies regarding the product.
60. Answer:
A new flu vaccine is needed each year because the flu virus changes (mutates) rapidly, and the strains each year usually differ from the previous year.
61. Answer:
Some of the things I should consider before making my decision would include the following: Is my friend a trained physician? What do reliable secondary scientific sources (e.g., WebMD) say about the vaccine? What do peer-reviewed scientific articles (primary sources might include CDC articles and definitely the Journal of American Medical Association) say about the vaccine, and is there any benefit other than preventing this year’s flu? Although this year’s vaccine might not prevent me from getting the flu this year, might it prevent my getting a flu that develops in the future? Is there any peer-reviewed, scientific evidence that getting the flu vaccine will actually give me the flu?
62. Answer:
I would tell my friend that although there seems to be a positive correlation (as one variable has risen, so has the other) between the use of cell phones in the developed world and the occurrence of autism, this data does not establish a cause-effect relationship between the two variables. There could be many other things influencing the autism rate. Someone would need to conduct scientific experiments to demonstrate a cause-effect relationship between these two variables.
63. Answer:
This type of study is a meta-analysis that combines, analyzes, and evaluates the results from multiple studies. The researchers’ conclusion is supported with solid science. First, the research team appears to have the appropriate credentials for investigating claims regarding vaccines and autism. Second, the study meets the standards of real science by including various lines of evidence and large sample sizes. Third, the study has been reviewed by other researchers specializing in the field of vaccines and then published in the primary literature. Fourth, there is no evidence of a conflict of interest; the researchers are not trying to sell us something or support a nonscientific belief.
64. Answer:
1) New vaccines are extensively tested on animals and/or cell lines before clinical trials on adult human volunteers even begin. Only if the vaccine is safe and effective will the U.S. FDA approve it for commercial sale. 2) Even after approval, every facility manufacturing vaccines is inspected by the FDA, each vaccine batch is tested for safety, purity, and potency, and anyone can report a vaccine adverse reaction to the Vaccine Adverse Event Reporting System (VAERS). 3) Before a vaccine is added to the official list of recommended immunizations, all of the data regarding that vaccine is reviewed by the Advisory Committee on Immunization Practices (ACIP) and then again by the director of the Centers for Disease Control (CDC).
65. Answer:
1.
B
2.
B
3.
A
4.
A
5.
B
6.
B
7.
B
8.
A
1.
B
2.
B
3.
A
4.
B
5.
A
6.
A
66. Answer:
Name: ___________________________ Class: _________________ Date: __________
Chapter 03 1.
2.
3.
The subatomic particles that possess a single negative charge and surround the nucleus are the a.
isotopes.
b.
protons.
c.
neutrons.
d.
electrons.
Nitrogen has seven protons, seven neutrons, and seven electrons. What is the atomic mass of nitrogen? a.
0u
b.
7u
c.
14 u
d.
21 u
The opioids shown here have what common chemical feature?
a.
They are all compounds.
4.
5.
b.
They are all elements.
c.
They are all isotopes.
d.
They all have the same structure.
In Figure 3.17, when researchers modified fentanyl to make NFEPP, what single change was made to the structure of the molecule? a.
An amino acid was replaced.
b.
An atom was added.
c.
A hydrophobic region was added.
d.
A double bond was created.
The bonds connecting the atoms in the following molecule are __________ bonds.
a.
polar, hydrogen
6.
b.
polar, covalent
c.
nonpolar, ionic
d.
nonpolar, covalent
Which one of the following images illustrates both hydrogen bonds and covalent bonds? a.
b.
c.
d.
7.
8.
O2, also referred to as atmospheric oxygen, is formed by a covalent bond between two oxygen atoms. This type of bond involves oxygen atoms a.
releasing protons.
b.
releasing electrons.
c.
sharing protons.
d.
sharing electrons.
Atoms in a single molecule of methane, CH4, share electrons. Methane is formed by __________ bonds joining __________ atoms. a.
hydrogen; two
b.
covalent; five
9.
10.
11.
c.
ionic; five
d.
ionic; two
The chemical reaction that represents photosynthesis is 6 H2O + 6 CO2 → C6H12O6+ 6 O2. What are the reactants? a.
H2O and CO2
b.
C6H12O6 and CO2
c.
H2O and O2
d.
C6H12O6 and CO2
The subatomic particles that possess a single negative charge, surround the nucleus, and are lost or gained by atoms called ions are the a.
isotopes.
b.
protons.
c.
neutrons.
d.
electrons.
Sodium chloride (table salt) is formed when positively charged sodium ions and negatively charged chloride ions are chemically attracted to each other. This attraction is best described as a(n) a.
hydrogen bond.
b.
ionic bond.
c.
covalent bond.
d.
solution.
12.
13.
14.
15.
In the chemical reaction that forms hydrogen peroxide (H2O2), hydrogen and oxygen share electrons, creating __________ bonds between the atoms. a.
covalent
b.
peptide
c.
hydrogen
d.
ionic
Ionic bonds __________, whereas covalent bonds __________. a.
form between the same two elements; form between different elements
b.
hold together compounds that do not dissolve in water; hold together molecules that dissolve in water
c.
hold together oppositely charged atoms; hold together atoms that share electrons
d.
consist of atoms with partial charges; consist of atoms with full positive and negative charges
When calcium (Ca2+) and chloride (Cl-) interact with one another, they bond using __________ bonds. a.
hydrogen
b.
peptide
c.
covalent
d.
ionic
Hydrogen and oxygen atoms are held together within an individual water molecule by __________ bonds. a.
hydrogen
b.
peptide
16.
17.
18.
19.
c.
polar covalent
d.
ionic
Which of the following is likely to participate in ionic bonding? a.
Li+
b.
H2 O
c.
He
d.
C6H12O6
Individual water molecules orient toward each other because of the __________ bonds that form between them. a.
covalent
b.
peptide
c.
hydrogen
d.
ionic
Which of the following is correct about hydrogen bonds? a.
Individually, they are very strong.
b.
They form between neighboring oxygen atoms.
c.
They do not involve binding with a hydrogen atom.
d.
They form due to partial positive and partial negative charges on atoms.
Which of the labeled areas of the water molecule in the following image possesses a partial negative charge?
20.
a.
A only
b.
B only
c.
C only
d.
A and C
If iodide ions (I-) were dissolved in water (as pictured here), they would be attracted to
a.
A only
21.
22.
23.
b.
B only
c.
C only
d.
A and C
Neighboring water molecules are held together with hydrogen bonds because a.
partially negatively charged oxygen atoms and partially positively charged hydrogen atoms on separate water molecules are attracted to one another.
b.
the hydrogen and oxygen atoms within a single water molecule share electrons equally.
c.
the oxygen and hydrogen atoms that participate in hydrogen bonding share electrons within a single valence shell.
d.
ionic interactions repel water molecules from hydrophobic oils that may be present in a solution.
Ice floats on water because a.
the crystal structure of ice is more regular than that seen in liquid water.
b.
the distance between water molecules in ice is greater than in liquid water.
c.
the cool temperature of ice reduces the extent of molecular motion relative to liquid water.
d.
when ice forms, the hydrogen bond in the water molecule becomes nonpolar; ice behaves like oil.
When sodium chloride (Na+Cl-) is dissolved in water, the sodium ion is a.
attracted to the hydrogen atoms of water molecules.
b.
repelled by the oxygen atoms of water molecules.
24.
25.
26.
c.
attracted to other sodium ions that are being dissolved.
d.
attracted to the oxygen atoms of water molecules.
A sample of pure water is analyzed for the atoms present. Which of the following would be the correct percentages of atoms present in the sample? a.
25.0 percent oxygen, 75.0 percent hydrogen
b.
50.0 percent oxygen, 50.0 percent hydrogen
c.
33.3 percent oxygen, 66.6 percent hydrogen
d.
66.6 percent oxygen, 33.3 percent hydrogen
Oil and water do not mix well because a.
water is polar and oil is nonpolar.
b.
only identical molecules of the same chemical can easily mix.
c.
water has hydrogen bonds and oil is polar.
d.
water and oil are covalently bonded.
You are given an unknown substance and asked to determine whether it is polar or nonpolar. The easiest way to do this would be to a.
determine whether the compound is held together by hydrogen bonds.
b.
determine the number of electrons in the compound’s outer shell.
c.
mix the compound with an ionic substance to see whether its bonds can withstand the pressure.
d.
determine whether the compound dissolves in water.
27.
28.
29.
30.
In making her morning tea, Dorothy drops a sugar cube into the hot water. She stirs the mixture but no longer sees the sugar cube at the bottom of her mug. In this scenario, the sugar is a.
nonpolar.
b.
the solvent.
c.
an acid.
d.
a solute.
In making her morning tea, Dorothy drops a sugar cube into some hot water. She stirs the mixture but no longer sees the sugar cube at the bottom of her mug. Based on her observation of sugar dissolving in hot water, she can properly conclude that the sugar is a.
hydrophobic.
b.
nonpolar.
c.
hydrophilic.
d.
inert.
A carwash attendant offers to treat Martin’s windshield with a protective agent. This substance coats the glass, causing beads of water to easily roll off during a rain shower. Which of the following must be correct about the protective agent? a.
It resists temperature changes well.
b.
It must be an acid.
c.
It is a polar substance.
d.
It must be hydrophobic.
The pH scale measures the a.
amount of water in a solution.
31.
32.
33.
34.
b.
likelihood that a solution will evaporate.
c.
concentration of hydrogen ions in a solution.
d.
number of atoms found within a molecule.
An acid is a polar substance that dissolves in water and a.
becomes nonpolar.
b.
leaves behind an OH- ion.
c.
accepts hydrogen ions from the solution.
d.
donates hydrogen ions to the solution.
After adding a small amount of Solution A to Solution B, the pH of Solution B declines from 8 to 3. Solution A must contain a.
a salt.
b.
a base.
c.
water only.
d.
an acid.
When ammonia (NH3) is dissolved in a solution, it accepts hydrogen ions from its surroundings. Ammonia is therefore a(n) a.
base.
b.
isotope.
c.
salt.
d.
acid.
A solution with a pH of 3 is
35.
36.
37.
a.
acidic.
b.
basic.
c.
nonpolar.
d.
neutral.
Of the following values, which indicates the most basic pH? a.
5
b.
7
c.
8
d.
10
Which of the following solutions has the highest concentration of free H+ ions? a.
pH 1
b.
pH 4
c.
pH 7
d.
pH 14
As shown in the following figure, the highest concentration of free hydrogen ions is found in
38.
a.
household ammonia.
b.
lemons.
c.
human blood.
d.
stomach acid.
According to the following figure, which of the following has a lower concentration of hydrogen ions?
39.
a.
milk.
b.
oranges.
c.
antacids.
d.
baking soda.
The most basic solution in the following figure is
40.
a.
seawater.
b.
borax.
c.
baking soda.
d.
tomatoes.
The most acidic solution in the following figure is
41.
a.
stomach acid.
b.
lemons.
c.
oven cleaner.
d.
pure water.
A solution with a pH of 4 is __________ acidic than a solution with a pH of 5. The solution with the pH of 4 has a __________ concentration of hydrogen ions than the solution with a pH of 5. a.
more; higher
b.
more; lower
42.
43.
44.
45.
c.
less; higher
d.
less; lower
Carbon atoms are bound to each other by __________ bonds. a.
ionic
b.
polar
c.
hydrogen
d.
covalent
Carbon’s prominence in living systems can be explained by the fact that a.
it forms weak reversible bonds.
b.
it bonds with up to three other atoms.
c.
carbon-based molecules can form long chains and rings.
d.
it does not form small molecules.
Which of the following is an organic compound? a.
water (H2O)
b.
methane (CH4)
c.
ammonia (NH3)
d.
carbon dioxide (CO2)
Astronauts returning from outer space studied samples taken from their lunar landing. They found that one of their samples was coated with organic compounds. Which of the following statements must be correct?
46.
47.
48.
a.
The compounds must be covered with ammonia (NH3) and water vapor.
b.
The samples must lack water but contain DNA.
c.
The samples must contain carbon atoms.
d.
The specimen must lack water, pesticides, and added hormones.
Carbon is an example of a(n) a.
compound.
b.
macromolecule.
c.
element.
d.
amino acid.
The central element found in organic molecules is a.
calcium.
b.
carbon.
c.
silicon.
d.
sodium.
Which of the following statements is true of proteins, carbohydrates, and nucleic acids? a.
All three are used to store genetic information.
b.
None of these macromolecules mixes well with water.
c.
Each of these molecules is built from a common set of monomers.
d.
All of these molecules are primarily used as energy-storage molecules.
49.
50.
51.
52.
A researcher in a laboratory tests a food item and identifies protein in it. The food item must also contain a.
glucose.
b.
lipids.
c.
amino acids.
d.
nucleotides.
Macromolecules are typically formed by repetitively adding small monomers together. Which macromolecule is properly matched with the appropriate monomer? a.
polypeptide—amino acid
b.
nucleic acid—amino acid
c.
polysaccharide—nucleotide
d.
triglyceride—cholesterol
A disaccharide consists of two a.
sugars.
b.
hydrocarbons.
c.
fatty acids.
d.
amino acids.
Nucleotides a.
are the building blocks of proteins.
b.
are involved in every chemical reaction in the cell.
c.
form physical structures such as hair.
d.
are the building blocks of nucleic acids.
53.
54.
55.
56.
The genetic material found in all living things is made of building blocks called a.
nucleotides.
b.
monosaccharides.
c.
phospholipids.
d.
steroids.
Which of the following are composed of the same monomers? a.
proteins and DNA
b.
RNA and cellulose
c.
starch and cellulose
d.
cholesterol and sucrose
Which of the following is the largest in size? a.
glucose
b.
protein
c.
carbon atom
d.
nucleotide
Which of the following could be built solely from glucose molecules? a.
fatty acids
b.
DNA
c.
oils
d.
starch
57.
58.
59.
A scientist has assembled 1.0 gram of protein, lipid, carbohydrate, and nucleic acids in separate tubes. They add each of these samples to a calorimeter, a device that determines the amount of energy present in the sample. Based on the role of these molecules in the body, predict which test tube will produce the most energy. a.
nucleic acids
b.
proteins
c.
carbohydrates
d.
lipids
Laura’s supervisor provides her with lipids, carbohydrates, proteins, and nucleic acids and asks her to determine their chemical components. Which of the following elements would she NOT expect to find in these items? a.
carbon
b.
iron
c.
hydrogen
d.
nitrogen
We use soap to clean ourselves better than we could with water alone. Soaps contain phospholipids that are responsible for the cleansing action. Based on this, predict which of the following materials would be needed to produce soap. a.
proteins
b.
triglycerides
c.
carbohydrates
d.
nucleic acids
60.
61.
62.
How many different amino acids are used to build proteins? a.
90
b.
20
c.
19
d.
4
Antibodies are an important class of human proteins that function in immune defense. If scientists fragmented antibodies under laboratory conditions, what chemical building blocks would they recover? a.
monosaccharides
b.
phospholipids
c.
amino acids
d.
nitrogenous bases
Based on these macromolecule images, what is a shared feature?
a.
They are all polar compounds.
b.
They are all organic compounds.
c.
They are all nonpolar compounds.
d.
They are all acidic compounds.
63.
Nitrogen has an atomic number of 7 and an atomic mass number of 14. Using the following image, describe the location and number of protons, neutrons, and electrons in nitrogen.
64.
Lithium, with an atomic number of 3, has a tendency to lose electrons when it chemically bonds to another atom. What type of chemical bonds does lithium usually form with other atoms? Explain how you determined your answer.
65.
During a study session, a biology classmate holds up a bottle of water and mentions that there are both hydrogen bonds and covalent bonds found within the liquid. Explain your classmate’s statement by describing the types of bonds that are found within the bottle of water.
66.
The bonds within an individual water molecule and between separate water molecules explain the special properties of water. Describe the type of bond within individual water molecules and the type of bond between separate water molecules. Then, list two unique properties of water.
67.
After giving a baby a bath, a parent applies baby oil to the child’s skin. How does the baby oil help the baby’s skin to retain moisture throughout the day? Explain the chemical basis of water retention in this example.
68.
Gina makes vinaigrette dressing with olive oil and vinegar and then shakes the jar vigorously. For a few minutes it appears as if the oil and vinegar have mixed. Then she notices the two liquids separating from each other. Describe why these two liquids do not stay together even after vigorous mixing.
69.
The pH value of pure water is 7.0. When Ralph measures the pH of rainwater in his neighborhood, he finds the pH value is 6.0. Which of these solutions has a higher concentration of hydrogen ions? What is the difference in the hydrogen ion concentration?
70.
Stomach acid has a pH value of 1.5–2.0. Antacids have a pH value of 10.5. Antacids are a common medication used to reduce the “burning” effect of stomach acid moving back up into the esophagus (the tube that carries food to the stomach). Describe how antacids affect the concentration of free hydrogen ions to provide relief from “heartburn.”
71.
There are four major classes of macromolecules found in living systems, and each uses a carbon skeleton as its structural backbone. Why is carbon regularly assembled to make important biological molecules?
72.
Indicate the basic subunits used to build each of the four major classes of macromolecules.
73.
Label each of the images as the subunit for a carbohydrate, protein, or nucleic acid. List two shared features between these subunits.
74.
A piece of genetic material has been isolated from an asteroid. Researchers are trying to determine if this is composed of RNA or DNA. Describe one criterion that could be used to determine if this is DNA or RNA.
75.
Match the type of bond associated with each description. Terms may be used more than once. a.
covalent
b.
hydrogen
c.
ionic __ 1. A positively charged sodium ion is attracted to a negatively charged chloride ion to form table salt. __ 2. Carbon shares electrons with oxygen atoms in a carbon dioxide molecule. __ 3. a weak electrical attraction that holds individual water molecules together __ 4. an unequal sharing of electrons within an individual water molecule
__ 5. Some structure in a protein molecule is due to weak electrical attractions.
76.
Use the molecule of ethanol shown in the following image to match the numbers with the questions they answer. Numbers may be used more than once. a.
0
b.
1
c.
2
d.
4
e.
8 __ 1. __ 2. __ 3. __ 4. __ 5.
77.
How many covalent bonds are indicated? How many valence electrons are in each carbon atom? How many electrons is the oxygen atom sharing? How many valence electrons are in each hydrogen atom? What is the total number of carbon atoms?
Using the following answer choices, match each characteristic with its macromolecule class. a.
lipids
b.
carbohydrates
c.
nucleic acids
d.
proteins __ 1. __ 2. __ 3. __ 4. __ 5. __ 6. __ 7.
participate in nearly every chemical reaction in living systems store and transmit genetic information speed chemical reactions act as short-term energetic molecules form the major framework of biological membranes exhibit various levels of structure function in energy storage and structural support
__ 8. used to create steroid molecules like cholesterol
Answer Key Chapter 03
1. Answer:
D
2. Answer:
C
3. Answer:
A
4. Answer:
B
5. Answer:
B
6. Answer:
A
7. Answer:
D
8. Answer:
B
9. Answer:
A
10. Answer:
D
11. Answer:
B
12. Answer:
A
13. Answer:
C
14. Answer:
D
15. Answer:
C
16. Answer:
A
17. Answer:
C
18. Answer:
D
19. Answer:
B
20. Answer:
D
21. Answer:
A
22. Answer:
B
23. Answer:
D
24. Answer:
C
25. Answer:
A
26. Answer:
D
27. Answer:
D
28. Answer:
C
29. Answer:
D
30. Answer:
C
31. Answer:
D
32. Answer:
D
33. Answer:
A
34. Answer:
A
35. Answer:
D
36. Answer:
A
37. Answer:
D
38. Answer:
C
39. Answer:
B
40. Answer:
A
41. Answer:
A
42. Answer:
D
43. Answer:
C
44. Answer:
B
45. Answer:
C
46. Answer:
C
47. Answer:
B
48. Answer:
C
49. Answer:
C
50. Answer:
A
51. Answer:
A
52. Answer:
D
53. Answer:
A
54. Answer:
C
55. Answer:
B
56. Answer:
D
57. Answer:
D
58. Answer:
B
59. Answer:
B
60. Answer:
B
61. Answer:
C
62. Answer:
B
63. Answer:
The atomic number tells us the number of protons, whereas the atomic mass is the sum of protons and neutrons. Therefore, nitrogen has seven protons, seven neutrons, and seven electrons. In the diagram, students should demonstrate that there are seven protons and seven neutrons in the atomic nucleus. The seven electrons should be drawn in the shells.
64. Answer:
When lithium loses electrons it becomes positively charged and participates in ionic bonding. Since lithium is positively charged, it will interact with negatively charged atoms.
65. Answer:
Your classmate is correct in their assessment of the bonds in the water. Within a water molecule, the hydrogen and oxygen atoms are held together by covalent bonds. Hydrogen bonds attract neighboring water molecules due to partial positive and partial negative charges on the hydrogen and oxygen atoms, respectively.
66. Answer:
Individual water molecules are held together by polar, covalent bonds. These bonds involve an unequal sharing of electrons that cause water molecules to have slightly positive and slightly negative ends. Hydrogen bonds are the relatively weak attractions that occur between the slightly negative end of one water molecule and the slightly positive end of another water molecule. The combination of the polarity of water molecules and the hydrogen bonds between them lead to the following properties of water mentioned in the textbook: water acts as the “universal solvent” capable of dissolving many substances, ice is less dense than liquid water, and water is a liquid at room temperature.
67. Answer:
Because the oil is hydrophobic and the water is hydrophilic, the two substances do not mix well. Coating the baby’s skin with baby oil surrounds the skin with a thin barrier that helps to prevent the loss of moisture since the two substances do not interact with each other. The two fail to mix because they do not share the same charged nature. Although water is electrically neutral, the oxygen and hydrogen ends of the molecule possess partial charges. The baby oil, on the other hand, is held together by nonpolar covalent bonds, so it has no partial charges.
68. Answer:
Oil is a nonpolar, hydrophobic substance that does not dissolve easily in water. Vinegar is a hydrophilic substance that is soluble in water. Hydrophobic and hydrophilic substances do not mix well and will separate as a result. Oil is also a less dense substance than vinegar and will rise to the top of an oil and vinegar solution.
69. Answer:
The rainwater has a 10-fold increase in the concentration of hydrogen ions when compared to pure water.
70. Answer:
Antacids are a base and bases remove free hydrogen ions from a solution. In the case of heartburn, highly acidic stomach acid is causing damage and pain. By adding antacids to the solution, the pH is raised as free hydrogen ions are accepted by the antacids (the solution becomes more basic) and the burning sensation is relieved.
71. Answer:
All of the major biological molecules (macromolecules) of living systems are organic molecules. As such, these molecules are formed using a carbon skeleton. This element is a central player because of its small size and need for four covalent bonds. Carbon readily participates in covalent bonding with other carbon atoms, forming single, double, and triple bonds. Carbon-carbon bonds may also branch or form rings. The carbon-carbon bond is also quite stable, which ensures the integrity of biological molecules in living systems.
72. Answer:
Carbohydrates are composed of monomers called monosaccharides. When amino acids are joined by peptide bonds, they form proteins. Nucleic acids such as DNA and RNA are built from nucleotide monomers. Lipids are not constructed in the same manner as the other three classes of macromolecules. This diverse class of macromolecules does not share a common monomer.
73. Answer:
The top image is a nucleotide, and the bottom image is an amino acid. The shared features between the two is the presence of covalent bonds and of carbon.
74. Answer:
The genetic material could be tested to see whether it was single stranded, which would indicate RNA, or double stranded, which would indicate DNA. The researchers could also look at the chemical structure of the nucleotides to see whether the sugar is ribose (RNA) or deoxyribose (DNA).
75. Answer:
76. Answer:
77. Answer:
1.
C
2.
A
3.
B
4.
A
5.
B
1.
E
2.
D
3.
C
4.
B
5.
C
1.
D
2.
C
3.
D
4.
B
5.
A
6.
D
7.
B
8.
A
Name: ___________________________ Class: _________________ Date: __________
Chapter 04 1.
2.
3.
Which of the following is a part of accepted cell theory? a.
Every living organism is composed of one or more cells, and all living cells have membrane-enclosed organelles.
b.
All living cells arise from preexisting cells, and all living cells have membrane-enclosed organelles.
c.
All living cells have membrane-enclosed organelles.
d.
Every living organism is composed of one or more cells, and all living cells arise from preexisting cells.
Select the smallest and most basic unit of life. a.
cell
b.
genome
c.
DNA
d.
nucleotide
Living organisms maintain a constant internal environment by sensing and responding to their internal conditions. This stable maintenance of internal conditions is known as a.
homeostasis.
b.
evolution.
c.
reproduction.
d.
sensation.
4.
5.
6.
7.
DNA is one of the features common to all known forms of life; it is used to a.
protect the outer membrane of cells.
b.
transfer information from parents to their offspring.
c.
obtain energy from the environment.
d.
sense changes within the environment.
The roots of a sunflower plant growing downward while the shoot grows upward and the flower turns toward the sun are examples of what characteristic of all living organisms? a.
They reproduce using DNA.
b.
They evolve through time.
c.
They make their own energy.
d.
They sense the environment and respond to it.
A species of butterflies gradually becomes darker in color over many generations; this is an example of which characteristic of living organisms? a.
They reproduce using DNA.
b.
They obtain energy from the environment to support metabolism.
c.
They can evolve as groups.
d.
They sense the environment and respond to it.
Which of these characteristics of living organisms are present in viruses? a.
composed of one or more cells
b.
can evolve as groups
c.
maintain energy from their environment
d.
obtain energy from their environment
8.
9.
10.
Adenine (A), thymine (T), guanine (G), and cytosine (C) are the __________ building blocks for DNA; they are organized in different combinations to code for all of the proteins needed to accomplish everything the cell does. a.
carbohydrate
b.
nucleotide
c.
protein
d.
lipid
Which of the following accurately describes viruses? a.
They are small, cellular infectious agents that are only capable of reproducing when inside a living cell, and they can attack plants as well as animals.
b.
Each is typically a piece of genetic material encased in proteins, and they can reproduce on their own.
c.
They can attack plants and animals, and each is typically a piece of self-replicating genetic material encased in a protein envelope.
d.
Typically a piece of genetic material encased in proteins; they are small, noncellular infectious agents that are only capable of reproducing when inside a living cell such as those of plants, animals, or bacteria.
Some antibiotics used to treat bacterial infections kill the bacteria by chemically punching holes in the cell wall of the bacteria, by preventing the bacteria from replicating their DNA, or by many other actions that ultimately cause cell death. Why do these antibiotics not work to kill viruses and cure people of viral infections? a.
Antibiotics cannot kill a virus because viruses are not living cells with cell walls to puncture, nor do they have the structures necessary for autonomous reproduction.
b.
Viruses are too virulent to be killed by those antibiotics.
11.
12.
13.
c.
Viruses are too quick for the antibiotics to work.
d.
Viruses mutate at a rate faster than the rate at which antibiotics can kill them.
Living cells have an intact phospholipid bilayer that separates the cell from its external environment; this structure is commonly referred to as the a.
nuclear envelope.
b.
protein coat.
c.
cell wall.
d.
plasma membrane.
Liposomes form spontaneously from __________ and are important because __________. a.
DNA; they provide a rigid structure to support the cell
b.
phospholipid monolayers; these phospholipid monolayers provide a stable barrier between the internal and external environments
c.
rigid cell walls; they provide support for the living cell and a barrier between the external and internal environments
d.
phospholipids and water; they provide a barrier between an external environment and an internal environment
An experiment mixed oil (lipids), organophosphate-containing detergent in water, and copper ions to act as a catalyst for a chemical reaction. Membranes budded off from the oil in this mixture. Which of the following is a reasonable and possible explanation of the experimental results? a.
The chemical reaction caused the organophosphates from the detergent to chemically combine with lipids from the oil to form phospholipids. The hydrophilic tails lined up toward each other with their hydrophobic heads pointing out toward the water; this configuration formed a phospholipid bilayer that pulled into a liposome.
14.
15.
b.
The chemical reaction caused the organophosphates from the detergent to chemically combine with lipids from the oil to form phospholipids with hydrophilic heads and hydrophobic tails. The hydrophobic tails lined up toward each other with their hydrophilic heads pointing out toward the water; this configuration formed a phospholipid bilayer that pulled into a spherical liposome.
c.
The copper ions permanently combined chemically with the lipids to form phospholipids. The hydrophilic tails lined up toward each other with their hydrophobic heads pointing out toward the water; this configuration formed a phospholipid bilayer that pulled into a liposome.
d.
The copper ions permanently combined chemically with the lipids and phosphates to form phospholipids. The hydrophilic tails lined up toward each other with their hydrophobic heads pointing out toward the water; this configuration formed a phospholipid bilayer that pulled into a liposome.
Phospholipids are large organic molecules with a hydrophilic, polar phosphate head connected to hydrophobic, nonpolar fatty acid tails. These molecules arrange themselves to form a mostly impermeable barrier between the fluid inside a liposome and its external environment by lining up a.
hydrophilic head to hydrophilic head, with the tails all facing outward from the center line of the membrane.
b.
hydrophobic tails facing each other at the center line of the membrane, with the hydrophilic heads facing outward, away from the center line of the membrane.
c.
hydrophobic tails facing hydrophilic heads.
d.
hydrophilic tails facing hydrophobic heads, with every other tail facing outward from the center line of the membrane.
Which of the following statements best describes the differences between the nuclear envelope and the plasma membrane? a.
The nuclear envelope consists of two concentric phospholipid bilayers, while the plasma membrane is only one phospholipid bilayer. Both membranes are selectively permeable.
16.
17.
18.
b.
The nuclear envelope consists of two concentric phospholipid bilayers, while the plasma membrane is only one phospholipid bilayer. Neither membrane is selectively permeable.
c.
Both membranes consist of two concentric phospholipid bilayers, are selectively permeable, and have pores.
d.
Both membranes consist of two concentric phospholipid bilayers, and neither is selectively permeable or has pores.
The permeability of a phospholipid bilayer membrane for a particular substance can be increased with help from transport a.
carbohydrates.
b.
phospholipids.
c.
receptors.
d.
proteins.
During the process of __________, water diffuses across a semipermeable membrane from an area where water is more concentrated to an area where water is less concentrated (it moves along the water concentration gradient). a.
osmosis
b.
active transport
c.
endocytosis
d.
pinocytosis
Cells naturally, without using energy, respond to changes in water concentration through the process of a.
endocytosis.
b.
osmosis.
19.
20.
21.
c.
phagocytosis.
d.
active transport.
The plasma membrane of some white blood cells contain __________ proteins that bind with proteins of cells such as bacteria that have invaded the human body. a.
channel
b.
receptor
c.
diffusion
d.
carrier
If the concentration of sugar molecules in water on side A of a selectively permeable membrane is 5 percent, and the concentration of sugar molecules in water on side B of a selectively permeable membrane is 15 percent, the water molecules will a.
mostly move from side B to side A because the water concentration is higher on side “B.”
b.
mostly move from side A to side B because the water concentration is higher on side “A.”
c.
mostly move from side A to side B because the water concentration is higher on side “B.”
d.
not move at all because the water concentrations are isotonic.
A screen door allows breezes to enter and aromas to exit but keeps out insects. Its function most resembles a.
the cytosol.
b.
the plasma membrane.
c.
the ER lumen.
d.
22.
23.
a ribosome.
Cheryl is in a lab attempting to prepare a slide of cow blood for observation in a wet mount. She places a small drop of the blood on a slide, adds a drop of 3 percent salt solution, and then covers all of it with a coverslip. After returning to her desk, she observes the slide with her microscope and notices that all of the red blood cells (RBCs) do not look like the nice round donut-shaped cells in her lab manual. Instead, the RBCs look very shriveled up. Her lab partner, Derek, has also made a slide, but the RBCs on his slide do look like the ones in the lab manual. Derek used a 0.9 percent salt (physiological saline) solution but the same vial of blood. The most plausible explanation for the appearance of the blood cells on Cheryl’s slide is that the a.
saline she used was hypotonic to the RBCs; this resulted in net water movement into the RBCs by osmosis.
b.
saline she used was isotonic to the RBCs; this resulted in no net movement of water into or out of the RBCs.
c.
saline she used was hypertonic to the RBCs; this resulted in net water movement out of the RBCs by osmosis.
d.
RBCs were hypertonic to the saline; this resulted in net water movement into the RBCs by osmosis.
Dialysis tubing is a selectively permeable membrane that can be filled with a solution to simulate a cell. A piece of dialysis tubing has been filled with a cloudy white solution of 5 percent starch, 5 percent egg albumin (protein), and 5 percent glucose (a small sugar) dissolved in water to simulate a cell. This simulated cell is weighed and then placed in a beaker of pure water. After soaking in the beaker solution for one hour, the simulated cell is once again weighed. Over time, the weight of the simulated cell can be expected to a.
increase because the cell is hypotonic to the beaker solution and water will enter the simulated cell through osmosis.
b.
decrease because the cell is hypertonic to the beaker solution and water will leave the simulated cell through osmosis.
24.
25.
c.
increase because the solution in the beaker is hypotonic to the simulated cell and water will enter the simulated cell through osmosis.
d.
decrease because the solution in the beaker is hypertonic to the simulated cell and water will leave the simulated cell through osmosis.
The following figure shows a beaker divided into two compartments by a semipermeable membrane that allows the passage of water molecules, but prevents the passage of sugar molecules. Assume that each sugar molecule represents a percentage point of sugar dissolved in the solution. Over time, the solution volume on the left side of the figure would __________. This is because the solution on the left side of the figure is __________ relative to the solution on the right.
a.
increase; hypertonic
b.
decrease; hypertonic
c.
decrease; hypotonic
d.
increase; hypotonic
Which of the following statements most accurately describes a selectively permeable membrane? a.
Solutes always move across a selectively permeable membrane from a region of higher concentration to a region of lower concentration.
b.
Charged molecules are always excluded from crossing the membrane.
26.
27.
28.
c.
All substances require specific transport proteins to pass through the membrane.
d.
Certain solutes move freely across the membrane by simple diffusion, while others require transport proteins; some substances are completely excluded from crossing the membrane.
If a bottle of perfume were spilled in the corner of a large lecture hall, the students sitting near that corner of the room would very quickly smell the perfume. Over time, the students sitting in the far corner of the room would smell the perfume. What phenomenon will have occurred to the perfume molecules that have entered the air? a.
osmosis
b.
facilitated diffusion
c.
active transport
d.
simple diffusion
A scientist is observing a membrane through which water and some small hydrophobic molecules can freely pass along a concentration gradient from high to low. However, some sugar molecules are too large to pass through the membrane either way without the assistance of passive transport proteins. Additionally, small Na+ ions and some proteins can pass through the membrane against the concentration gradient, but both require the assistance of active transport proteins. What general type of membrane are they observing? a.
impermeable
b.
impenetrable
c.
semipermeable
d.
completely permeable
Which of the following substances can pass through the plasma membrane by simple diffusion and facilitated diffusion?
29.
30.
a.
water (H2O)
b.
sodium ions (Na+) and hydrogen ions (H+)
c.
oxygen (O2) and carbon dioxide (CO2)
d.
sugars and amino acids
Ross places carrot sticks into a jar of water and refrigerates the jar overnight. The next day the carrot sticks are crisp and crunchy. The most likely explanation of why they became crunchy after soaking in water is that the water was __________ to the carrot cells, resulting in the net movement of water __________ the cells. a.
hypertonic; into
b.
hypotonic; out of
c.
hypertonic; out of
d.
hypotonic; into
Why would hydrophilic substances such as sodium ions (Na+), hydrogen ions (H+), sugars, and amino acids be unable to simply diffuse across a plasma membrane? a.
They readily mix with the hydrophobic tails that form the core of the phospholipid bilayer.
b.
They are repelled by the hydrophilic heads of the phospholipids that form the phospholipid bilayer.
c.
They do not readily mix with the hydrophobic tails forming the core of the phospholipid bilayer; therefore, they must move across by facilitated diffusion.
d.
They do not readily mix with the hydrophobic tails forming the core of the phospholipid bilayer; therefore, the only way they can move into the cell is by endocytosis.
31.
32.
33.
An amoeba, a protozoan that moves by pseudopodia, approaches a smaller protozoan and extends its pseudopodia (extensions of cytoplasm in plasma membrane) around the smaller protozoan. Once the amoeba’s pseudopodia completely surround the other protozoan, the amoeba’s plasma membrane pinches off by folding back into the amoeba and creates a vesicle containing the smaller protozoan. This vesicle is now within the amoeba itself and will soon fuse with other vesicles containing digestive enzymes. This is an example of a.
pinocytosis.
b.
exocytosis.
c.
facilitated diffusion.
d.
phagocytosis.
A white blood cell (WBC) encounters bacteria in a scrape on the knee of a child who has fallen off a bicycle. The WBC’s job is to take the bacteria inside itself and destroy it. If the bacteria are too large to be transported via transported proteins, how will the WBC most likely take them in? a.
exocytosis
b.
pinocytosis
c.
facilitated diffusion
d.
phagocytosis
A protein molecule, transferrin, that is embedded in the plasma membrane recognizes iron molecules and causes the plasma membrane to fold in around the iron and take it into the cell. This is an example of a.
exocytosis.
b.
diffusion.
c.
receptor-mediated endocytosis.
d.
pinocytosis.
34.
35.
36.
Which of the following would be likely to move through a plasma membrane by simple diffusion? a.
water (H2O), carbon dioxide (CO2), and oxygen (O2)
b.
polysaccharides, large protein molecules, and low-density lipoprotein particles
c.
bacteria and yeast
d.
sodium ions (Na+), hydrogen ions (H+), sugars, and amino acids
Neurotransmitters are chemicals that are released by nerve endings. These chemicals are often large and unable to pass through the membrane, so the nerve cell packages them in a vesicle that can fuse with the plasma membrane. The inside of the vesicle opens to the outside of the cell, releasing the neurotransmitters. This type of transport of cellular products is called a.
pinocytosis.
b.
receptor-mediated endocytosis.
c.
exocytosis.
d.
phagocytosis.
Cells lining blood vessels can form vesicles outside of the cell that can fold into the cell, taking in fluids from the outside environment. This is an example of a.
pinocytosis.
b.
receptor-mediated endocytosis.
c.
exocytosis.
d.
phagocytosis.
37.
38.
39.
40.
A factory with an office that controls the information sent to separate rooms for each of the manufacturing and shipping processes would be analogous to a a.
virus.
b.
prokaryotic cell with a nucleus.
c.
prokaryotic cell without a nucleus.
d.
eukaryotic cell with a nucleus.
The enzymes needed to perform photosynthesis in plant cells are closely associated with a.
chloroplasts.
b.
smooth ER.
c.
mitochondria.
d.
lysosomes.
Prokaryotes and eukaryotes are primarily distinguished by the absence or presence of a.
ribosomes.
b.
plasma membranes.
c.
organelles.
d.
cell walls.
Mitochondria are required for a.
photosynthesis.
b.
export of proteins.
c.
mitosis.
d.
41.
42.
43.
cellular respiration.
Martin observes a wet mount slide preparation using the compound light microscope in the lab room. He observes layers of cells that have a definite, rigid, rectangular shape; there appears to be a nucleus in all of the cells and there are many oval-shaped green structures that seem to be moving around inside of the cells in an orderly fashion. What general cell type is he most likely observing? a.
prokaryotic and plant
b.
prokaryotic and animal
c.
eukaryotic and plant
d.
eukaryotic and animal
Ribosomes are very small nonmembranous structures that can either exist freely in the cytoplasm or be embedded in the rough endoplasmic reticulum of a cell. They are associated with the synthesis of a.
lipids.
b.
proteins.
c.
nucleic acids.
d.
carbohydrates.
The smooth endoplasmic reticulum a.
manufactures steroid (lipid) hormones.
b.
produces the energy needed to run chemical reactions in the cell.
c.
converts sunlight into chemical energy.
d.
stores water, nutrients, and enzymes.
44.
45.
46.
47.
The Golgi apparatus a.
stores the cell’s genetic material.
b.
sorts proteins and lipids and sends them to their final destination.
c.
captures energy from sunlight and sends it to the mitochondria.
d.
manufactures lipids and hormones.
The boundary that surrounds the contents of the nucleus is called the a.
plasma membrane.
b.
nuclear envelope.
c.
nuclear pore.
d.
cytoskeleton.
Which of the following statements is true of chloroplasts? a.
They produce proteins used by other parts of the cell.
b.
They capture energy from sunlight.
c.
They give an animal cell its shape.
d.
They contain an entire copy of a cell’s genetic material.
Human muscle cells need large amounts of ATP to function in the movement of the body, which is why __________ are especially abundant in muscle cells. a.
mitochondria
b.
ribosomes
c.
vacuoles
d.
lysosomes
48.
49.
50.
In plants, the epidermis layer functions like a covering of skin to protect the leaf, while vascular bundles carry water and nutrients through the leaf. The palisade mesophyll layer is responsible for most of the photosynthesis that occurs, while the spongy mesophyll layer underneath it aids in the exchange of gases (CO2 and O2) and water vapor. In which leaf tissues would one expect to find the highest density of chloroplasts? a.
epidermis
b.
vascular bundles
c.
spongy mesophyll
d.
palisade mesophyll
Which of the following would be the best analogy for the function of the Golgi apparatus? a.
the machine that assembles a product
b.
a worker in a factory who places labels on products and then packs them into a shipping box
c.
the garbage truck that hauls away the wastes produced as a product is made
d.
the blueprints for making the product
Select the observation that supports endosymbiotic theory. a.
Nuclear envelopes have small openings called nuclear pores.
b.
Plant cells and many prokaryotes have cell walls surrounding the plasma membrane.
c.
Eukaryotic organisms can be either unicellular or multicellular.
d.
Mitochondria and chloroplasts contain DNA just like prokaryotic cells.
51.
52.
53.
A solid waste (garbage) transfer facility that sorts and breaks down garbage into recyclables and waste to be thrown away in the landfill would be a suitable analogy for which cellular organelle? a.
smooth ER
b.
rough ER
c.
lysosome
d.
nucleus
The flexible poles providing structure to a soft-sided tent most closely resemble the a.
endoplasmic reticulum in a bacterial cell.
b.
Golgi apparatus in a plant cell.
c.
cytoskeleton in an animal cell.
d.
nucleus in a eukaryotic cell.
The endoplasmic reticulum (ER) is a single membrane continuous with the nuclear envelope and a series of interconnected sacs throughout the cell. Why might it be beneficial to the cell for the ER to be continuous with the nuclear envelope? It might be beneficial for the ER and nuclear envelope to be connected because it a.
takes less energy, DNA, carbohydrates, and phospholipids for the ER to synthesize centrioles.
b.
is easier for messages to get from the nucleus to the ER where proteins and lipids are made for the cell; this would require the use of less energy.
c.
would make it easier for the nucleus to actually carry out cellular respiration.
d.
would make it easier for the ER to carry out photosynthesis.
54.
Using what you know about cell theory and viruses, explain why viruses are not alive.
55.
When scientists such as J. C. Venter and Daniel Gibson engineer a cell constructed with synthetic DNA in the laboratory, do they challenge accepted cell theory? If so, which part of cell theory do they challenge? Briefly explain your answer.
56.
Examine the following infographic. Are all bacteria (prokaryotes) likely to be 3 µm in length and all protozoans (eukaryotes) likely to be 500 µm in size? Support your answer using information from the infographic.
57.
How are prokaryotic and eukaryotic cells similar? How are these two cell types different?
58.
Label the plasma membrane in the following image. Use the following terms: cellular environment, external environment, plasma membrane, hydrophilic heads, hydrophobic tails, energy, CO2, amino acid, and transport proteins.
59.
The following figure depicts a transport protein in a plasma membrane. The dark blue molecules represent sodium ions being transported out of the cell. Is the transport of the sodium ions active or passive? Support your answer by describing evidence that is visible in the figure and stating its significance regarding your answer.
60.
The following figure depicts transport proteins in a plasma membrane. Molecules are moving through the plasma membrane. How are the molecules moving across the membrane? Is this transport active or passive? Support your answer by describing evidence that is visible in the figure and stating its significance regarding your answer.
61.
Examine the following photo. This photo shows low-density lipoprotein (LDL) particles bound to receptors on the outside of a plasma membrane. Suppose you view the same cell later and notice that the LDL particles are now enclosed in vesicles inside of the cell. What would you propose as the explanation for how the LDL particles arrived in their new location? Support your explanation.
62.
Explain the process through which cells lining blood vessels bring in pockets of fluids from the bloodstream. Is this process specific or nonspecific?
63.
If a white blood cell is approximately 18 µm in diameter, which of the cell types or viruses seen in the following infographic would it be large enough to engulf? Describe the process the white blood cell would use to engulf another cell.
64.
What additional structures would the cell shown here need to become a plant cell?
65.
There are cells in the human pancreas that produce insulin, a protein hormone that is important in the regulation of blood sugar levels. Once the pancreas cells have produced the initial peptide (small string of amino acids) component of insulin, it must be finished, packaged, and shipped out of the cell. Which organelles would likely be involved in this process of finishing, packaging, and shipping of a protein hormone? Include a brief, general description of what happens to the hormone at each organelle and the plasma membrane.
66.
Indicate which cell in the figure below is the plant cell and which is the animal cell. Label all cellular structures 1–12. Include a brief description of each structure’s function with its label.
67.
Match the following cellular structures with their primary function. a.
photosynthesis
b.
regulates what moves in and out of a cell
c.
structure and support for a cell
d.
site for lipid and hormone manufacture
e.
site for protein production
f.
enzymatic breakdown of large molecules
g.
assemble proteins
h.
cellular respiration
i.
water and solute storage
j.
location of DNA
k.
internal organization and structural support
l.
directs protein and lipid products to their final destinations __ 1. __ 2. __ 3. __ 4. __ 5. __ 6. __ 7. __ 8. __ 9. __ 10. __ 11. __ 12.
central vacuole nucleus cytoskeleton mitochondrion ribosomes rough endoplasmic reticulum smooth endoplasmic reticulum Golgi apparatus lysosome plasma membrane cell wall chloroplast
Answer Key Chapter 04
1. Answer:
D
2. Answer:
A
3. Answer:
A
4. Answer:
B
5. Answer:
D
6. Answer:
C
7. Answer:
B
8. Answer:
B
9. Answer:
D
10. Answer:
A
11. Answer:
D
12. Answer:
D
13. Answer:
B
14. Answer:
B
15. Answer:
A
16. Answer:
D
17. Answer:
A
18. Answer:
B
19. Answer:
B
20. Answer:
B
21. Answer:
B
22. Answer:
C
23. Answer:
C
24. Answer:
A
25. Answer:
D
26. Answer:
D
27. Answer:
C
28. Answer:
A
29. Answer:
D
30. Answer:
C
31. Answer:
D
32. Answer:
D
33. Answer:
C
34. Answer:
A
35. Answer:
C
36. Answer:
A
37. Answer:
D
38. Answer:
A
39. Answer:
C
40. Answer:
D
41. Answer:
C
42. Answer:
B
43. Answer:
A
44. Answer:
B
45. Answer:
B
46. Answer:
B
47. Answer:
A
48. Answer:
D
49. Answer:
B
50. Answer:
D
51. Answer:
C
52. Answer:
C
53. Answer:
B
54. Answer:
Cell theory states that all living things are made of cells, and cells arise from preexisting cells. Viruses do not have the cellular organelles and structures needed to maintain life, metabolize nutrients, or reproduce on their own. Viruses are not cells, so they cannot be alive.
55. Answer:
The engineering of such a cell is a challenge to the “all cells arise from preexisting cells” portion of cell theory because a new cell has been generated without dividing a preexisting cell into two new cells. OR: The process does not challenge cell theory because the DNA is actually a copy of a preexisting cell’s DNA, and therefore it actually does arise from a preexisting cell.
56. Answer:
There are likely to be sizes of prokaryotic bacteria and eukaryotic protozoans other than those shown for the bacterium, E. coli, and the protozoan, Amoeba proteus. Human cells are eukaryotic and come in many different sizes. Even viruses (which are not actually alive) come in different sizes. This would lead one to think that bacteria and protozoa would also be different sizes.
57. Answer:
All cells contain DNA as a genetic material, ribosomes to synthesize proteins, and a plasma membrane to separate the internal cytoplasm from the external environment. Only eukaryotic cells possess membrane-enclosed organelles and a membrane-enclosed nucleus. Eukaryotic cells are much larger and more complex than prokaryotic cells.
58. Answer:
(1) external environment (2) cellular environment (3) energy (4) transport proteins (5) plasma membrane (6) hydrophilic heads (7) hydrophobic tails (8) CO2 (9) amino acid
59. Answer:
The sodium ion transport depicted is active transport. The illustration indicates that the concentration of sodium ions is higher on the outside of the cell than it is within the cell. Whenever a substance is moved into or out of a cell against the concentration gradient, it typically requires the input of cellular energy to accomplish active transport.
60. Answer:
The molecules are moving across the membrane by facilitated diffusion. The molecules are moving through membrane proteins and with the concentration gradient from high to low, and there is no evidence that energy is being used; this is a passive transport system.
61. Answer:
The most likely way the LDL particles entered the cell was through receptor-mediated endocytosis. The receptors on the plasma membrane that bound the LDL particles were probably specific for the LDL particles. The membrane began to fold into a pocket inside of the cell and eventually pinched off, forming a vesicle there.
62. Answer:
Cells lining blood vessels would form pockets of fluids from the bloodstream through the nonspecific process of pinocytosis. Pinocytosis happens when the plasma membrane folds into the cell, forming a vesicle that is filled with whatever fluids and solutes happen to be around the cell at the time.
63. Answer:
The white blood cell (WBC) is larger than rhinovirus, influenza virus, measles virus, E. coli bacterium, and red blood cell. Therefore, it would be large enough to engulf them. The WBC would phagocytize the cell or virus by lining up beside it and folding its own plasma membrane around the other cell or virus. This fold would extend inward into the cell and pinch off as a vesicle.
64. Answer:
This prokaryotic cell would need a double membrane–enclosed nucleus that contains the DNA. This cell would also need a variety of membrane-enclosed organelles such as the mitochondria, endoplasmic reticulum, Golgi apparatus, a large central vacuole, and some chloroplasts. Plant cells and many prokaryotes, including the bacterium shown here, have a cell wall that surrounds the plasma membrane.
65. Answer:
The insulin would be finished by the rough ER, budded into a transport vesicle, and transported to the Golgi apparatus, where it might undergo further modification as it moves through it. At some point, a transport vesicle containing the insulin will bud off the Golgi apparatus, which will have chemically tagged it to be destined to hook up with the plasma membrane. Once it arrives at the plasma membrane, the membrane of the vesicle fuses with the plasma membrane opening to the outside of the cell and releases the hormone through exocytosis.
66. Answer:
The cell on the left is the plant cell. The cell on the right is the animal cell. (1) nucleus (location of DNA) (2) rough endoplasmic reticulum (site for protein synthesis) (3) smooth endoplasmic reticulum (lipid hormone synthesis) (4) Golgi apparatus (transports protein and lipid products to final destination) (5) lysosome (enzymatic breakdown of large molecules) (6) small vacuole (transporting proteins and lipids, shown in animal cell only) (7) mitochondrion (cellular respiration) (8) cytoskeleton (organization and structural support) (9) plasma membrane (regulates what moves in and out of cell) (10) cell wall (structure and support for plant cell) (11) chloroplast (photosynthesis) (12) large central vacuole (water and solute storage)
67. Answer:
1.
I
2.
J
3.
K
4.
H
5.
G
6.
E
7.
D
8.
L
9.
F
10.
B
11.
C
12.
A
Name: ___________________________ Class: _________________ Date: __________
Chapter 05
1.
2.
The following illustration indicates that photosynthesis and cellular respiration are both complementary and balanced. An excess of sugars produced fossil fuels like coal and petroleum; this suggests that in the past,
a.
the amount of photosynthesis exceeded the amount of cellular respiration.
b.
sugars were only one of several products of photosynthesis.
c.
reduced carbon-rich molecules could be produced independently from the photosynthetic process.
d.
the energy released from respiration must have exceeded the energy used in photosynthesis.
Chemical reactions that break down lipids are a.
catabolic.
20.
21.
22.
c.
bottlenecks
d.
phenotypes
Several related bird species live in a desert. One species is much smaller than the other species. This small species nests in holes in cacti. Because the bird is so small, it can easily squeeze between the spines of the cactus and create a well-protected nest. This is an example of a.
genetic drift.
b.
mutation.
c.
natural selection.
d.
gene flow.
Two different species may have similar features because of a.
genetic drift.
b.
the founder effect.
c.
a bottleneck.
d.
descent from a common ancestor.
Convergent evolution occurs when natural selection causes distantly related organisms to a.
evolve into the same species despite the fact that they are members of separate populations.
b.
merge into one continuous population because of reversals in continental drift.
c.
evolve both analogous and homologous characteristics.
d.
evolve similar structures in response to similar environmental challenges.
23.
24.
25.
26.
Two unrelated species evolving to look more similar due to environmental pressures is called a.
gene flow.
b.
genetic drift.
c.
convergent evolution.
d.
divergent evolution.
Convergent evolution produces a.
genetic drift.
b.
lines of common descent.
c.
homologous traits.
d.
analogous traits.
Both insects and humans evolved jointed legs to allow locomotion on land. These structures are considered analogous because insects and humans a.
stopped evolving at different times in Earth’s history.
b.
evolved from different ancestors.
c.
cannot breed.
d.
faced different environmental challenges during evolutionary time.
Some finches on the Galápagos Islands eat insects, an unusual food for finches to eat. These finches a.
evolved from a lineage of birds other than finches that ate insects.
b.
learned their habits from local birds.
c.
switched to insects because they tasted better than their usual food.
d.
27.
28.
29.
30.
fill roles that birds other than finches would fill in other places.
The common ancestor of birds and bats had forelimbs but not wings. The wings on the forelimbs of birds and bats are quite different structurally. The bird wing is covered by feathers, and the bat wing consists of a thin layer of stretched skin. Select the correct statement regarding bird and bat wings. a.
Bird and bat wings are analogous traits due to shared ancestry.
b.
Bird and bat wings are homologous traits due to convergent evolution.
c.
Bird and bat wings are analogous traits due to convergent evolution.
d.
Bird and bat wings are homologous traits due to shared ancestry.
Mammals and octopuses independently evolved similar complex camerastyle eyes. This is an example of a.
convergent evolution.
b.
divergent evolution.
c.
disruptive selection.
d.
directional selection.
The central driver of evolution is a.
gene flow.
b.
genetic drift.
c.
natural selection.
d.
disruptive selection.
Which of the following is an example of gene flow? a.
mutation
31.
32.
33.
b.
genetic drift
c.
horizontal gene transfer
d.
sexual selection
For a population to evolve, there must be genetic differences between organisms in that population. These differences arise by a.
mutation.
b.
a change in an organism’s behavior.
c.
natural selection.
d.
common descent.
Genetic variation is based on a.
the inheritance of alleles accumulated during the lifetime of an individual.
b.
differences in genotypes between the individuals in a population.
c.
the accumulation of mutations in somatic cells (as opposed to gametes).
d.
the formation of new combinations of alleles during asexual reproduction.
Ultraviolet (UV) light causes mutations within skin cells. Is UV light a major driving force in the evolution of animals? a.
Yes; UV light is always present outside and can produce both favorable and harmful mutations in skin cells. Only the favorable mutations will be passed on to the next generation.
b.
Yes; a mutation in the skin cell will result in an organism that is better protected from the sun. This individual will be more likely to survive and pass on this mutation to the next generation.
34.
35.
36.
c.
No; only mutations in gametes will be passed on to the next generation. Only mutations that are passed on to offspring contribute to evolution.
d.
No; only mutations that have a favorable adaptive quality will be passed on to the next generation. UV light produces only harmful mutations.
A mutation in a gene produces the identical protein to the original gene and, therefore, an identical trait. Will evolution act upon this mutation? a.
No, because evolution acts upon phenotypes.
b.
Yes, because evolution acts upon phenotypes.
c.
Yes, because mutations contribute to evolution.
d.
No, because mutations do not contribute to evolution.
Gene flow occurs a.
as a result of genetic drift.
b.
when an individual migrates between two otherwise isolated populations of a species.
c.
as a result of mutations in one population but not in another.
d.
when individuals within a population interbreed.
During gene flow, a.
chance events alter the gene pool of a population.
b.
alleles exchange between populations.
c.
gametes circulate within a population.
d.
crossing-over creates new combinations of alleles during gamete formation.
37.
38.
39.
40.
While on a camping trip, Brian collects a white tadpole from a pond and takes it home. The tadpole develops into a white bullfrog. When the frog gets too big, he releases it into a local pond. The next year, several white bullfrogs are observed in the pond. This is an example of a.
conjugation.
b.
natural selection.
c.
gene flow.
d.
sexual selection.
Gene flow between two populations a.
makes the genetic composition of the two populations more similar.
b.
eliminates harmful alleles.
c.
magnifies the effects of genetic drift.
d.
creates genetic differences between the populations.
Which of the following is NOT a step in the evolutionary process? a.
Mutation results in the formation of new alleles, and sexual reproduction results in new combinations of alleles.
b.
New genes are introduced into a population when members of that population mate with members of other species and produce offspring.
c.
Genetic variation is inherited by the next generation of a population.
d.
Genetic drift, gene flow, and natural selection cause allele frequencies to change over time.
The illustration shows an example of