TEST BANK
Genetics Essentials: Concepts and Connections
Benjamin A. Pierce
5th Edition
,Table of Contents
Chapter 01 Introduction to Genetics 1
Chapter 02 Chromosomes and Cellular Reproduction 15
Chapter 03 Basic Principles of Heredity 32
Chapter 04 Extensions and Modifications of Basic Principles 59
Chapter 05 Linkage, Recombination, and Eukaryotic Gene Mapping 98
Chapter 06 Chromosome Variation 115
Chapter 07 Bacterial and Viral Genetic Systems 139
Chapter 08 DNA-The Chemical Nature of the Gene 152
Chapter 09 DNA Replication and Recombination 181
Chapter 10 From DNA to Proteins-Transcription and RNA Processing 198
Chapter 11 From DNA to Proteins-Translation 224
Chapter 12 Control of Gene Expression 244
Chapter 13 Gene Mutations, Transposable Elements, and DNA Repair 278
Chapter 14 Molecular Genetic Analysis and Biotechnology 298
Chapter 15 Genomics and Proteomics 314
Chapter 16 Cancer Genetics 332
Chapter 17 Quantitative Genetics 346
Chapter 18 Population and Evolutionary Genetics 366
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Test Bank - Genetics Essentials: Concepts and Connections, 5th Edition (Pierce, 2022)
Chapter 01: Introduction to Genetics
1. Albinism is rare in most human populations, occurring at a frequency of about 1 in 20,000 people. However,
the trait occurs at a frequency of 1 in 200 in certain Hopi villages of Black Mesa in Arizona. Explain in terms of
natural selection why albinism is so rare in most human populations.
ANSWER: In most populations, there is fairly strong selection against albinism because albinos don’t produce
melanin, causing their skin cells not to be protected from the damaging effects of sunlight. Also, the
lack of melanin in their eyes causes them to have poor eyesight. Finally, in most cultures albinos are
seen as abnormal, and they are not normally sought out for marriage and mating. Therefore, in most
populations the alleles that cause albinism are selected against, and they decrease in frequency or are
kept at a low level, causing the recessive trait to be rare.
2. Albinism is rare in most human populations, occurring at a frequency of about 1 in 20,000 people. However,
the trait occurs at a frequency of 1 in 200 in certain Hopi villages of Black Mesa in Arizona. Explain in terms of
natural selection why the trait is so much more common among the Hopis of Black Mesa.
ANSWER: Albinos occupy a privileged position among the Hopis of Black Mesa. In this culture, albinos are
viewed as especially pretty, clean, and intelligent, and they often occupy positions of leadership.
Albinos are celebrated in the villages as a sign of purity of Hopi blood in the community.
Furthermore, albinos are often excused from normal male field labor because of their sensitivity to
sunlight, causing them to be left behind in the village with the women during the daytime. This
allows them extra mating opportunities compared to the other men of the village. Therefore, the
alleles that cause albinism are either selected for in this culture or at least not selected against as
strongly as in other cultures, allowing the trait to occur at a much higher frequency.
3. Which one of the following pairings between the subdiscipline of genetics and the phenomenon is
INCORRECT?
a. evolution—population genetics
b. gene regulation—molecular genetics
c. allelic frequency alteration—population genetics
d. arrangement of genes on chromosome—transmission genetics
e. chemical nature of the gene—transmission genetics
ANSWER: e
4. Which one of the following topics of research belongs to the discipline of transmission genetics?
a. inheritance pattern of gene alleles
b. mechanism of DNA replication
c. gene expression patterns
d. evolution
e. chemical modification of nucleic acids
ANSWER: a
5. The complete genetic makeup of an organism is referred to as its
a. chromosome.
b. alleles.
c. locus.
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Test Bank - Genetics Essentials: Concepts and Connections, 5th Edition (Pierce, 2022)
d. genome.
e. phenotype.
ANSWER: d
6. Identify a TRUE statement from the following descriptions concerning genetics.
a. The theory of pangenesis states that all living organisms are composed of cells.
b. Bacteria and viruses are not useful in studying genes and inheritance because they are structurally
and metabolically different from eukaryotic cells.
c. Charles Darwin accurately described the laws of inheritance in his landmark book, On the Origin of
Species.
d. Many human traits, such as skin and hair color, are determined by more than a single gene.
e. Evolution can occur without genetic changes in the population.
ANSWER: d
7. Identify a FALSE statement from the following descriptions of genetics.
a. Humans first applied genetics to the domestication of plants and animals between approximately
10,000 and 12,000 years ago.
b. Some viruses use RNA to carry their genetic information.
c. Albinism results from a mutation in the genes that control the synthesis and storage of melanin.
d. All human traits that display blending inheritance are affected by a single gene.
e. The process by which genetic information is copied and decoded is similar for all forms of life.
ANSWER: d
8. Which of the following species is considered a model genetic organism?
a. the plant Linaria vulgaris
b. the deer mouse Peromyscus maniculatus
c. the worm Caenorhabditis elegans
d. the frog Hyla chrysoscelis
e. the chimpanzee Pan troglodytes
ANSWER: c
9. Which of the following would serve the LEAST well as a model for understanding basic mechanisms of
inheritance?
a. fruit flies
b. humans
c. yeast
d. mice
e. zebrafish
ANSWER: b
10. Which of the following statements is TRUE?
a. Each subdiscipline of genetics is very specific as to what is explored and does not overlap with the
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other subdisciplines.
b. All phenotypes or traits are always determined by multiple genes.
c. Albinism arises from the overexpression of the gene that controls the synthesis and storage of
melanin.
d. Humans make excellent model organisms because they have a variety of well-defined traits.
e. None of the statements provided are true.
ANSWER: e
11. Which of the following statements is CORRECT?
a. All genomes are encoded in DNA only.
b. All genomes are encoded in nucleic acids.
c. All genomes are encoded in proteins only.
d. The genetic instructions are decoded completely differently in each organism.
e. Molecular studies suggest life evolved from multiple primordial ancestors.
ANSWER: b
12. Which of the following traits would make a species useful as a model genetic organism? (Select all that
apply.)
a. large number of progeny
b. long generation time
c. small size
d. ability to be studied in a laboratory
e. ability to be propagated inexpensively
ANSWER: a, c, d, e
13. Which one of the following topics belongs to a different subdiscipline of genetics when compared with the
rest?
a. mechanism of gene regulation
b. allele frequencies of a certain gene in different environments
c. transcription
d. chemical alternation of chromosomes
e. mechanism of DNA replication
ANSWER: b
14. The fruit fly Drosophila melanogaster is an important model system for studying inheritance in animals and
genetic control of animal development, including humans. If researchers ultimately want to understand a
biological process in humans, why might they want to study the process in fruit flies first? (Select all that
apply.)
a. Fruit flies are relatively easy to genetically manipulate and to isolate mutations.
b. Fruit flies have short generation times and produce relatively large numbers of progeny.
c. Fruit flies have simpler genomes than do humans.
d. Fruit flies share all important physiological and developmental processes with humans.
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e. Fruit flies are small and easy to raise.
ANSWER: a, b, c, e
15. The complete genetic makeup of any organism is referred to as a
a. phylogeny.
b. phenotype.
c. genome.
d. genotype.
e. single-nucleotide polymorphism.
ANSWER: c
16. A change in allele frequency within a population over time leads to
a. a genome.
b. a phenotype.
c. a genotype.
d. mutations.
e. evolution.
ANSWER: e
17. Assume that a geneticist is doing a study with a wild mouse species. She captures 100 of these mice, takes a
DNA sample from each, and sequences the same specific gene from each mouse. This gene has two alleles
within this population. She then calculates the frequency of each of the two alleles from the sequencing results.
Which subdivisions of genetics would this study include?
a. transmission and population genetics
b. transmission and molecular genetics
c. molecular genetics only
d. molecular and population genetics
e. transmission genetics only
ANSWER: d
18. Albinism is rare in most human populations, occurring at a frequency of about 1 in 20,000 people. However,
the trait occurs at a frequency of 1 in 200 in certain Hopi villages of Black Mesa in Arizona. In light of this
example and others that you might be aware of, what can you conclude about particular alleles such as the allele
for albinism?
a. An allele that leads to an abnormal phenotype will be rare in most populations but common in Native
American populations.
b. An allele that leads to an abnormal phenotype will not be beneficial in any population.
c. An allele that leads to an abnormal phenotype may be beneficial in some environments but harmful
in others.
d. An allele that leads to an abnormal phenotype will rise in frequency after many generations.
e. An allele that leads to an abnormal phenotype will soon disappear from a population.
ANSWER: c
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19. The fruit fly Drosophila melanogaster is an important model system for studying inheritance in animals and
genetic control of animal development, including humans. Evaluate fruit flies as a model system for human
biology. What are their strengths and weaknesses as a model system?
ANSWER: Strengths—Fruit flies have proven to be an excellent model system for studying aspects of biology
that they share with humans. Fruit flies are simpler in structure and physiology than humans and
have a much simpler genome. They are small and easy to raise, they have a short generation time,
and they produce a large number of offspring. Their chromosomes have been mapped and their
genomes analyzed extensively. It is relatively easy to isolate and study mutants that are defective in
specific processes of interest. These characteristics make them ideal for genetic studies of biological
processes.
Weaknesses—Some aspects of fruit fly genetics and development are not shared with humans.
Therefore, some features discovered in fruit flies will not apply directly to humans. Also, humans
have many features that fruit flies lack. Fruit flies will not serve well as a model system for studying
these features of human biology.
20. What common features of heredity suggest that all life on Earth evolved from a common ancestor?
ANSWER: Despite the remarkable diversity of life on Earth, all genomes are encoded in nucleic acids. With
few exceptions, the genetic code is common to all forms of life. Finally, the process by which
genetic information is copied and decoded is remarkably similar for all forms of life.
21. Why might bacteria and viruses be good model organisms for studying the basics of inheritance? Describe
two advantages over studying genetics in mice, dogs, or humans.
ANSWER: Bacteria and viruses have their genetic material (DNA) organized into genes, just like other
organisms, so the basics of inheritance are the same in bacteria and viruses as in other organisms.
The genetic systems of bacteria and viruses are simpler when compared to higher eukaryotic
organisms such as mice, dogs, or humans: they have fewer genes, fewer chromosomes, and less
DNA.
Bacteria and viruses reproduce more quickly than higher eukaryotic organisms: the generation time
is shorter than for mice, dogs, or humans.
Bacteria and viruses are easy and less expensive to grow (take up less space, have less complicated
nutritional needs) than vertebrates.
22. Many good ideas in science ultimately turn out to be incorrect, and this has happened several times in the
history of genetics. In your own words, state one idea in the history of genetics that turned out to be incorrect.
ANSWER: Answers will vary but might include pangenesis, inheritance of acquired characteristics,
preformationism, or blending inheritance, which are all described in section 1.1. Pangenesis—The
idea that information needed to encode each body structure is stored in that structure and transported
to the reproductive organs and passed to the embryo at conception. Inheritance of acquired
characteristics—The idea that traits acquired through use during one’s lifetime can be passed to
one’s offspring. Preformationism—The idea that the sperm or egg carries a tiny preformed person
whose development simply involves enlargement. Blending inheritance—The idea that the genetic
material is a fluid that gets blended during sexual reproduction between a male and female, resulting
in the production of traits in the offspring that are blended intermediates of those of the parents.
23. Many good ideas in science ultimately turn out to be incorrect, and this has happened several times in the
history of genetics. Why do you think a particular idea was widely accepted by scholars of that time? Include in
your answer some evidence in favor of the idea, observations that seemed to support the idea, or other rationale
for accepting the idea.
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ANSWER: Answers will vary but should include specific evidence or observations that support the idea.
Examples:
Pangenesis—It is reasonable to assume that the information needed to build a structure must reside
in that structure. It is less obvious that the information might also reside in other structures.
Therefore, it is reasonable to envision the information being stored in each structure and transported
to the reproductive structures before being passed to the next generation.
Inheritance of acquired characteristics—Observations to support this view would have been
commonplace. For example, a man with a muscular physique would often have sons with muscular
physiques. A talented musician often produced children with musical talent.
Preformationism—It would have been hard for people before the late 1800s to imagine how a
complex organism could build itself from a single undifferentiated cell. Indeed, the problem has
occupied developmental biologists for over 100 years. Preformationism is easier to understand. Add
to that the poor optics of microscopes at that time, and it is easy understand how early biologists
might have thought they could see a preformed person in a sperm or an egg, such as in Figure 1.11.
Blending inheritance—For example, a mating between a tall person and a short person producing a
person of medium stature might have suggested blending inheritance.
24. Many good ideas in science ultimately turn out to be incorrect, and this has happened several times in the
history of genetics. Summarize the evidence that ultimately caused an idea to be rejected by modern geneticists.
ANSWER: Answers will vary but should include specific evidence or observations that do not support the idea.
Pangenesis—Observations of animals with body parts lost to injury producing normal offspring
would not support pangenesis. Inheritance of acquired characteristics— Experiments were
conducted in which body parts were removed and normal offspring were produced, showing that the
acquired characteristic was not inherited. Also, experiments in which offspring are raised in an
environment different from that of their parents and do not develop their parents’ traits would
suggest that the environment influences development of these traits. Preformationism—Eventually
better microscopes were produced that proved that gametes do not contain preformed people. Also,
we eventually came to understand that both sperm and egg contribute genetic information during
sexual reproduction. Blending inheritance—Mendel showed that genes behave as particles that are
not blended or changed during inheritance.
25. Describe one way in which discoveries in genetics currently impact your daily life apart from this course.
ANSWER: Answers will vary, but the best answers will include one or more specific discoveries in genetics
and describe how they affect the student personally. Examples could come from those listed in
section 1.1 or from the student’s background. This question and Questions 52 and 53 will work best
if students are asked to consider ahead of time how these discoveries might impact their lives. For
example, students might discuss the role of genetics and genetic technology in the Green Revolution
of the 1950s and 1960s, which greatly expanded food production throughout the world, making food
more efficient, more affordable, and more available to world populations. A much smaller part of
the world’s population works in agriculture, freeing up more people for work in other industries.
They might also discuss the use of genetically modified crops in agriculture, including a significant
proportion of corn and soybeans in the United States and other countries.
26. Describe one way in which discoveries in genetics will likely impact your life in the future.
ANSWER: An example would be the use of genetic tests in medical practice. Genetic tests are already fairly
commonplace and will become more common in the near future. In the future, most people will be
offered one or more genetic tests as part of their ordinary medical care. They will need to understand
the basis of the tests and their limitations, as well as how to interpret results and how to use the
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information provided.
Genome editing of humans, as with the CRISPR-modified babies born in 2019, may influence
humankind more generally. Rules and regulations and their enforcement vary greatly through the
world.
27. Describe a discovery in genetics or an area of current research that you are concerned about that might have
a negative impact on your life in the future. Explain why you think it might have a negative impact on you
personally.
ANSWER: Again, answers will vary, but an example is the possible abuse of genetic information about
individuals that is becoming more available. Many people worry that results from genetic tests, for
example, could be used to discriminate against individuals in the workplace and in the insurance
marketplace. The Genetic Information Nondiscrimination Act offers limited protection against
genetic discrimination, but the possibility of negative consequences from such tests remains.
Human genome editing is very controversial and could have unforeseen negative consequences not
only to the edited individual’s life but more broadly.
28. The experiments of Gregor Mendel can be placed into which subdivision of genetics?
a. molecular genetics
b. population genetics
c. transmission genetics
d. molecular genetics and transmission genetics
e. population genetics and transmission genetics
ANSWER: c
29. Among the model genetic organisms, Escherichia coli, a single-celled bacterium, is a prokaryote;
Saccharomyces cerevisiae, one-celled yeast, is a eukaryote, as are Caenorhabditis elegans, a multicellular
nematode worm, and Arabidopisis thaliana, a multicellular plant. Which of these organisms would NOT
contain membrane-bound organelles?
a. Escherichia coli
b. Saccharomyces cerevisiae
c. Escherichia coli and Saccharomyces cerevisiae
d. Caenorhabditis elegans
e. Caenorhabditis elegans and Arabidopisis thaliana
ANSWER: a
30. In the late 1990s, what important discovery in genetics was made?
a. The three-dimensional structure of DNA was described, which showed how DNA might be
replicated.
b. The first recombinant DNA experiments were performed that started the biotechnology field.
c. DNA sequencing methods were first discovered.
d. Genes were found to be located on chromosomes.
e. Tiny RNAs were discovered that play important roles in the regulation of gene expression.
ANSWER: e
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31. CRISPR/Cas9 is a powerful new method that allows
a. DNA sequencing to be performed very quickly so that numerous individual genomes can be
sequenced in a short period of time.
b. precise editing of specific DNA sequences in living cells.
c. the identification of genes involved in important medical conditions.
d. the introduction of genes from one species into another species.
e. the arrangement of genes on chromosomes.
ANSWER: b
32. The golden mutation in the zebrafish was useful because of which of the following results?
a. It led to the discovery of a similar gene in humans that is involved in skin pigmentation.
b. It led to the development of new varieties of wheat.
c. It led to the ability to identify many of the genes that result in an increase in heart attacks.
d. It allowed the zebrafish to be grown in captivity and become commercially profitable.
e. It became the first gene in a model organism to be sequenced.
ANSWER: a
33. What commonsense observation makes the theory of preformationism unlikely?
a. An individual may inherit traits found in both of his or her parents.
b. Anatomical changes such as loss of a limb are not seen in the offspring of an individual.
c. Evolution requires genetic change in populations.
d. Alleles that result in abnormal phenotypes may be less common in some populations than in others.
e. Offspring often look more like their parents than unrelated individuals.
ANSWER: a
34. What commonsense observation makes the theory of acquired characteristics UNLIKELY?
a. An individual may inherit traits found in both of his or her parents.
b. Anatomical changes such as loss of a limb are not seen in the offspring of an individual.
c. Evolution requires genetic change in populations.
d. Alleles that result in abnormal phenotypes may be less common in some populations than in others.
e. Offspring often look more like their parents than unrelated individuals.
ANSWER: b
35. Which of the following theories of inheritance is currently considered TRUE?
a. germ-plasm theory
b. pangenesis
c. blending inheritance
d. inheritance of acquired characteristics
e. None of these theories is considered true based on new evidence.
ANSWER: a
36. Which of the following theories of inheritance is no longer accepted as TRUE?
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