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Chapter 2
Genetics and Evolution
MULTIPLE CHOICE
1. The fundamental physical and functional unit of heredity is called the _______________.
a. chromosome
b. physical trait
c. species
d. gene
e. genus
W 2. The molecular basis of a gene was not known until
a. observed in a microscope by the Austrian monk, Gregor Mendel.
b. deduced rather than observed by the naturalist, Charles Darwin.
c. discovered during the 20th century when the electron microscope was invented.
d. observed in the sex cells of eels by Sigmund Freud.
e. deduced rather than observed by Gregor Mendel as a result of his experiments with
garden peas.
W 3. The smallest working units in biological classificatory systems and which are
reproductive isolated populations or groups of populations capable of interbreeding to
produce fertile offspring are called
a. genus.
b. genes.
c. species.
d. genome.
e. genetic code.
4. Modern taxonomy, or the science of classification, is based on
a. Body structure and growth
b. Body structure and function
c. Body structure, growth and function
d. Body structure, growth, function and protein structure
e. Body structure, growth, function, protein structure and genetic material
W 5. The hand of a human and the wing of a bat are __________________ structures, while
the wings of birds and butterflies are _________________ structures.
a. analogous, homologous
b. homologous, analogous
c. kingdom, phylum
d. suborder, subfamily
e. higher order, lower order
W 6. Genes are portions of molecules of long strands of which form chromosomes, or
_______________.
a. codons
b. DNA
c. RNA
d. ribosomes
e. transcriptions
7. In humans there are ____________ pairs of chromosomes.
a. 46
b. 102
c. 23
d. 12
e. 4
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8. Which of the following statements best expresses the major difference between mitosis
and meiosis?
a. Mitosis is cell division in animals; meiosis is cell division in humans.
b. Mitosis is the process by which a single cell with X number of chromosomes divides
into two cells, each with the same number of chromosomes; meiosis is the process by
which a single cell with X number of chromosomes goes through two stages of
division, producing four new cells each with X/2 (half the original number) of
chromosomes.
c. Mitosis is the process by which chromosomes are divided; meiosis is the process by
which DNA is divided.
d. Mitosis is the process by which cells divide; meiosis is the process by which cells are
joined together.
e. none of the above
9. If you have a chromosome pair on which the alleles for a single gene are identical (for
example, if you have the genotype AA for blood type in the ABO system), this pair is
described as _______________.
a. incomplete penitence
b. anthropomorphic
c. heterozygous
d. homozygous
e. genotypic
W 10. To say that the allele for type A blood is dominant to the one for type O means an
individual whose blood type genes are heterozygous, with one A and one O allele, will
have type ___________ blood.
a. O
b. A
c. AO
d. AB
e. OO
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11. Physical traits such as height, skin color, or liability to disease, are controlled by multiple
genes, or __________________.
a. dominant genes
b. recessive genes
c. polygenetic inheritance
d. hemoglobin
e. none of the above
W 12. Generation after generation, the bullfrogs in a farm pond look much alike, have the same
cells, and exhibit the same behavior when breeding. The _______________________ of
the population appears to remain stable over time.
a. Hardy-Weinberg principle
b. gene pool
c. a dominant allele
d. a recessive allele
e. a genotype
W 13. Evolution can best be defined as
a. changes in allele frequencies in populations
b. microevolution
c. a group of individuals that can and do interbreed
d. all the genetic variants possessed by members of a population
e. both a and d
14. The ultimate source of evolutionary change is _______________.
a. a single gene
b. genetic drift
c. founder effect
d. a recessive gene
e. mutation
Genetics and Evolution
W 15. Chance fluctuations of allele frequencies in the gene pool of a population
a. come about due to random events at the population level.
b. illustrate the operation of polygenes.
c. illustrate the phenomenon of incomplete dominance of the allele for normal
hemoglobin.
d. come about due to random events at the individual level.
e. both a and c
16. The study of inheritance in individuals tells us about how genes can be combined and
recombined through sexual reproduction, but to see how species change over time as
natural selection favors some combinations over others, we need to look at
_______________.
a. two individuals
b. populations
c. gene flow
d. genetic drift
e. directional selection
17. Adaptation is best described as
a. a series of beneficial adjustments to the environment.
b. not an active process but rather the outcome of natural selection.
c. the way humans make beneficial adjustments to their environment through culture as
well as biology.
d. all of the above
e. only a
18. Ultimately, all natural selection is measured in terms of
a. homozygous communities.
b. the heterozygous communities.
c. the gene pool.
d. mutations.
e. reproductive success.
19. As a consequence of the process of natural selection
a. populations generally become well adapted to their environments.
b. you can predict the chances that any one individual will display some phenotypic
characteristic.
c. stability, rather than change is promoted.
d. all of the above
e. a and c
W 20. Sickle-cell anemia
a. came to the attention of geneticists when it was observed that most North Americans
who suffer from it are of African ancestry.
b. was traced to abnormalities in populations that live in a clearly defined belt across
tropical Central Africa.
c. is notable in areas where high rates of deadly form of malaria is common.
d. all of the above.
e. a and c only
W 21. The Hardy-Weinberg principle
a. describes an evolving population.
b. is a theoretical model of a population that is not evolving.
c. expresses algebraically the ratio of homozygous and heterozygous genotypes that
would exist if the frequency of alleles in a gene pool remained stable from one
generation to the next.
d. can be used to compare with an actual population to see if evolution is occurring in
the actual population.
e. all of the above except a
22. A chance creation of a new allele is called a _______________.
a. mutation
b. meiosis
c. genotype
d. genetic drift
e. directional selection
Genetics and Evolution
23. Among the following factors that affect the genetic stability of a gene pool, which is the
ultimate source of new genes that are added to the gene pool?
a. genetic drift
b. gene flow
c. mutation
d. random mating
e. natural selection
24. Which of the following statements about mutation is correct?
a. The rate at which mutations occur in populations is constant.
b. Mutation does not contribute to the variability of a gene pool.
c. All mutations are harmful.
d. All mutations are caused by environmental factors external to the body, such as
chemicals in food or X-rays.
e. Some genes can cause other genes to mutate (mutator genes).
25. Changes in the frequency of genes in a gene pool caused by accidental, random, chance
events are _______________.
a. called gene flow
b. called genetic drift
c. more likely to occur in small populations
d. both a and c
e. both b and c
26. Which of the following situations is likely to result in genetic drift?
a. a volcanic eruption on a small island that wipes out half the population of 100 iguanas
b. a tidal wave that destroys 50 homes in a seaside community of three million people
c. a political order that results in the purposeful, selective killing of all people with red hair
d. all of the above
e. none of the above
27. Imagine a rock slide that kills five people from a small town of a population of 1,000
could significantly alter the frequencies of alleles in the local gene pool. This is an
example of a particular kind of genetic drift known as
a. gene flow.
b. genetic reconstruction.
c. founder effects.
d. mutation.
e. none of the above.
28. The introduction of alleles from the gene pool of one population into that of another is
called _______________.
a. mutation
b. genetic drift
c. gene flow
d. natural selection
e. convergent evolution
29. The last 500 years have seen the introduction of Spanish and African alleles into Central
and South American populations from Spanish colonists and African slaves. The change
in the gene pool is caused by _______________.
a. natural selection
b. gene flow
c. genetic drift
d. mutation
e. convergent evolution
30. Natural selection _______________.
a. means the ability of some individuals to kill enemies and survive
b. refers to the tendency for moral goodness to win out over moral badness in human
societies
c. refers to the ability of some individuals to breed
d. occurs when individuals possess certain genetically based traits that help them have
more offspring, and thus contribute a larger share of genes to future gene pools
e. means “survival of the fittest”
31. The process by which a population becomes better adapted to its biological and social
environment is _______________.
a. adaptation
b. mutation
c. gene flow
d. genetic drift
e. meiosis
32. Which of the following represents an example of natural selection?
a. Two nations go to war. After ten years, one side completely wipes out the other side.
The radiation caused by their use of nuclear weapons makes everyone sterile so the
victors are unable to have any children.
b. In a population of fish, some have a very unusual mutation that enables them to get
oxygen directly from the air as well as from water that runs over their gills. During a
time of drought, these were the only fish able to survive, and their descendants
possessed the same gene.
c. A young man works very hard at his studies, spends 10 years in graduate school, and
goes to work for a company that sends him all over the world. He meets presidents
and kings and by the time he is 40, he is earning a million dollars a minute. He dies at
the age of 49. He has been too busy being successful to get married and have a
family.
d. all of the above
e. none of the above
33. Despite the usefulness of a large brain in a cultural environment, the size of the human
brain has not increased significantly for the last 200,000 years. This is an example of
_______________.
a. directional selection
b. stabilizing selection
c. convergent evolution
d. divergent evolution
e. isolating mechanism
34. The case of sickle-cell anemia illustrates that a trait that may bring misery to an
individual is adaptive from the point of the view of the _______________.
a. population
b. gene
c. DNA
d. environment
e. chromosome
35. What technique do anthropologists use to analyze genetic differences between humans
and apes?
a. comparative anatomy
b. mutational projection analysis
c. DNA sequencing
d. evolutionary comparisons
e. linear evolution analysis
36. The allele for abnormal hemoglobin (the sickling gene, S) has a high frequency in parts
of the world where malaria is common. What cultural factor contributes to the presence
of malaria?
a. food foraging
b. farming
c. deep sea fishing
d. industrialism
e. solar technology
37. As a population’s genetic variation changes from one generation to another, genetic
change is reflected in _______________.
a. single celled bacteria
b. the homogeneity of organism
c. visible differences between organisms
d. random events
e. progressive improvement
Genetics and Evolution
38. _______________ classified things on the basis of overall similarities into small groups,
or species.
a. Darwin
b. Linnaeus
c. Gould
d. Mendel
e. Wallace
39. A _______________ is a population or group of populations capable of interbreeding that
is reproductively isolated from other such populations.
a. genera
b. taxonomy
c. homology
d. species
e. codon
40. As generation succeeds generation, nature selects the most advantageous variations, and
species evolve. So obvious did the idea seem in hindsight that _______________, one of
the pillars of 19th century British science, remarked: “How extremely stupid of me not to
have thought of that.”
a. Aldous Huxley
b. Charles Darwin
c. Alfred Russell Wallace
d. Stephen J. Gould
e. Thomas Henry Huxley
41. Your textbook points out that some simple living things without nucleated cells, such as
the retrovirus that causes _______________, contain their genetic information only as
RNA.
a. malaria
b. MS
c. cancer
d. tuberculosis
e. AIDS