Question 1

If global warming permits mosquitoes to live at higher altitudes than they currently do, then in which direction should the entire plot in the correct distribution below be shifted? a.  b.  c.  d.

Accepted Answer

A)  Curve A will be shifted to the right. 
B)  Curve B will be shifted to the right. 
C)  Curve C will be shifted upward. 
D)  Curve D will be shifted upward.

Question 2

You sample a population of butterflies and find that 56% are heterozygous at a particular locus. What should be the frequency of the recessive allele in this population?

Accepted Answer

A)  0.07 
B)  0.08 
C)  0.09 
D)  0.70 
E)  Allele frequency cannot be determined from this information.

Question 3

Every HIV particle contains two RNA molecules. If two genes from one RNA molecule become detached and then, as a unit, get attached to one end of the other RNA molecule within a single HIV particle, which of these is true?

Accepted Answer

A)  There are now fewer genes within the viral particle. 
B)  There are now more genes within the viral particle. 
C)  A point substitution mutation has occurred in the retroviral genome. 
D)  The retroviral equivalent of crossing over has occurred, no doubt resulting in a heightened positive effect. 
E)  One of the RNA molecules has experienced gene duplication as the result of translocation.

Question 4

During breeding season, one should expect female house finches to prefer to mate with males with the brightest red feathers. Which of the following terms are appropriately applied to this situation?

Accepted Answer

A)  sexual selection 
B)  mate choice 
C)  intersexual selection 
D)  Three of the responses are correct. 
E)  Two of the responses are correct.

Question 5

In a very large population, a quantitative trait has the distribution pattern shown in Figure 21.3.
  Figure 21.3
-If the curve in Figure 21.3 shifts to the left or to the right, there is no gene flow, and the population size consequently increases over successive generations. Which of the following is (are) probably occurring? 1. immigration or emigration
2) directional selection
3) adaptation
4) genetic drift
5) disruptive selection

Accepted Answer

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

Question 6

Arrange the following from most general (i.e., most inclusive) to most specific (i.e., least inclusive): 1. natural selection
2) microevolution
3) intrasexual selection
4) evolution
5) sexual selection

Accepted Answer

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

Question 7

Heterozygote advantage should be most closely linked to which of the following?

Accepted Answer

A)  sexual selection 
B)  stabilizing selection 
C)  random selection 
D)  directional selection 
E)  disruptive selection

Question 8

Which of the following is most likely to produce an African butterfly species in the wild whose members have one of two strikingly different color patterns?

Accepted Answer

A)  artificial selection 
B)  directional selection 
C)  stabilizing selection 
D)  disruptive selection 
E)  sexual selection

Question 9

Use the following information to answer the following questions.
In those parts of equatorial Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the β hemoglobin alleles in the human gene pool.
-With respect to the sickle-cell allele, what should be true of the β hemoglobin locus in U.S. populations of African-Americans whose ancestors were from equatorial Africa? 1. The average heterozygosity at this locus should be decreasing over time.
2) There is an increasing heterozygote advantage at this locus.
3) Diploidy is helping to preserve the sickle-cell allele at this locus.
4) Frequency-dependent selection is helping to preserve the sickle-cell allele at this locus.

Accepted Answer

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

Question 10

Hardy-Weinberg equilibrium must occur in populations where

Accepted Answer

A)  an allele remains fixed. 
B)  no genetic variation exists. 
C)  natural selection is not operating. 
D)  All three of the responses above are correct. 
E)  Only two of the responses above are correct.

Question 11

The higher the proportion of loci that are "fixed" in a population, the lower is that population's

Accepted Answer

A)  nucleotide variability only. 
B)  chromosome number only. 
C)  average heterozygosity only. 
D)  nucleotide variability, average heterozygosity, and chromosome number. 
E)  nucleotide variability and average heterozygosity.

Question 12

Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true?

Accepted Answer

A)  Each bird evolved a deeper, stronger beak as the drought persisted. 
B)  Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted. 
C)  Each bird that survived the drought produced only offspring with deeper, stronger beaks than seen in the previous generation. 
D)  The frequency of the strong-beak alleles increased in each bird as the drought persisted.

Question 13

In the year 2500, five male space colonists and five female space colonists (all unrelated to each other) settle on an uninhabited Earthlike planet in the Andromeda galaxy. The colonists and their offspring randomly mate for generations. All 10 of the original colonists had free earlobes, and 2 were heterozygous for that trait. The allele for free earlobes is dominant to the allele for attached earlobes.
-Which of these is closest to the allele frequency in the founding population?

Accepted Answer

A)  0.1 a, 0.9 A 
B)  0.2 a, 0.8 A 
C)  0.5 a, 0.5 A 
D)  0.8 a, 0.2 A 
E)  0.4 a, 0.6 A

Question 14

Use the following information to answer the following questions.
In those parts of equatorial Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the β hemoglobin alleles in the human gene pool.
-In the United States, the parasite that causes malaria is not present, but African-Americans whose ancestors were from equatorial Africa are present. What should be happening to the sickle-cell allele in the United States, and what should be happening to it in equatorial Africa?

Accepted Answer

A)  stabilizing selection; disruptive selection 
B)  disruptive selection; stabilizing selection 
C)  disruptive selection; directional selection 
D)  directional selection; disruptive selection 
E)  directional selection; stabilizing selection

Question 15

Adult male humans generally have deeper voices than do adult female humans, which is the direct result of higher levels of testosterone causing growth of the larynx. If the fossil records of apes and humans alike show a trend toward decreasing larynx size in adult females and increasing larynx size in adult males, then

Accepted Answer

A)  sexual dimorphism was developing over time in these species. 
B)  intrasexual selection seems to have occurred. 
C)  stabilizing selection was occurring in these species concerning larynx size. 
D)  selection was acting more directly upon genotype than upon phenotype.

Question 16

Use the following information to answer the following questions.
In those parts of equatorial Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the β hemoglobin alleles in the human gene pool.
-Considering the overall human population of the U.S. mainland at the time when the slave trade brought large numbers of people from equatorial Africa, what was primarily acting to change the frequency of the sickle-cell allele in the overall U.S. population?

Accepted Answer

A)  natural selection 
B)  gene flow 
C)  genetic drift 
D)  founder effect 
E)  Two of the responses are correct.

Question 17

If the original finches that had been blown over to the Galápagos from South America had already been genetically different from the parental population of South American finches, even before adapting to the Galápagos, this would have been an example of

Accepted Answer

A)  genetic drift. 
B)  the bottleneck effect. 
C)  the founder effect. 
D)  genetic drift and the founder effect. 
E)  all three of these.

Question 18

What is true of natural selection?

Accepted Answer

A)  Natural selection is a random process. 
B)  Natural selection creates beneficial mutations. 
C)  The only way to eliminate harmful mutations is through natural selection. 
D)  Mutations occur at random; natural selection can preserve and distribute beneficial mutations. 
E)  Mutations occur when directed by the good of the species; natural selection edits out harmful mutations and causes populations to adapt to the beneficial mutations.

Question 19

Sexual dimorphism is most often a result of

Accepted Answer

A)  pansexual selection. 
B)  stabilizing selection. 
C)  intrasexual selection. 
D)  intersexual selection. 
E)  artificial selection.

Question 20

Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing

Accepted Answer

A)  nonrandom mating. 
B)  geographic isolation. 
C)  genetic drift. 
D)  gene flow.

Exam 21: The Evolution of Populations

If global warming permits mosquitoes to live at higher altitudes than they currently do, then in which direction should the entire plot in the correct distribution below be shifted? a. b. c. d.