Question 1

Which of the following best describes the effect of mutation on allele frequencies in a large population over a short period of time?

Accepted Answer

Mutation has little effect on allele frequencies because it occurs infrequently.

Question 2

A population of birds is suddenly reduced from 10,000 to 100 individuals due to a wildfire. Which evolutionary mechanism is most likely to affect allele frequencies in this scenario?

Accepted Answer

Bottleneck effect

Question 3

Which of the following scenarios best illustrates the founder effect?

Accepted Answer

A few individuals migrate to a new island and establish a population with different allele frequencies than the original population.

Question 4

Nonrandom mating can affect Hardy-Weinberg equilibrium by:

Accepted Answer

Increasing the frequency of homozygotes without changing allele frequencies

Question 5

Which of the following is NOT a requirement for Hardy-Weinberg equilibrium?

Accepted Answer

Nonrandom mating

Question 6

Gene flow is best defined as:

Accepted Answer

The transfer of alleles between populations

Question 7

Which equation represents the Hardy-Weinberg principle for a gene with two alleles, $$A$$ and $$a$$, where $$p is $$the frequency of $$A$$ and $$q is $$the frequency of $$a$$?

Accepted Answer

$$p^2 + 2pq$$ + $$q^2 = 1$

Question 8

Relative fitness is defined as:

Accepted Answer

The contribution of an individual to the gene pool of the next generation compared to others

Question 9

Which mode of selection favors individuals at both extremes of a trait, potentially leading to two distinct phenotypes?

Accepted Answer

Disruptive selection

Question 10

A population of rabbits has fur color controlled by a single gene with two alleles, $$B ($$black) and $$b ($$white). If $$p = 0.7$$ and $$q = 0.3$$, what is the expected frequency of heterozygotes under Hardy-Weinberg equilibrium?

Accepted Answer

$$2pq = 0.42$$

Question 11

Which of the following would most likely increase genetic variation in a population?

Accepted Answer

Gene flow from a different population

Question 12

If a population is experiencing directional selection, what is the expected outcome for the trait under selection?

Accepted Answer

The trait's average value will shift toward one extreme.

Question 13

Which evolutionary mechanism is most likely to cause a loss of genetic variation in a small population?

Accepted Answer

Genetic drift

Question 14

A population of fish in a lake is isolated from other lakes. Over time, a few fish from a neighboring lake migrate in and breed. What is the most likely effect on the genetic makeup of the original population?

Accepted Answer

Increase in genetic variation due to gene flow

Question 15

Which of the following is an example of stabilizing selection?

Accepted Answer

Birds with very short or very long wings are less likely to survive, while those with average wing length are favored.

Question 16

Which of the following statements about genetic drift is TRUE?

Accepted Answer

Genetic drift can lead to the loss of alleles from a population.

Question 17

A population of 1000 individuals has two alleles for a gene: $$A$$ and $$a. If $$the frequency of $$A is$$ $$0.6$$, what is the expected number of individuals with genotype $$AA$$ under Hardy-Weinberg equilibrium?

Accepted Answer

$$p^2$$ 	imes 1000 = 0.36 	imes 1000 = 360$$

Question 18

Which process is most likely to bring a population out of Hardy-Weinberg equilibrium?

Accepted Answer

Gene flow

Question 19

In a population, the transfer of alleles from one population to another is called:

Accepted Answer

Gene flow

Question 20

Which of the following is a direct consequence of the bottleneck effect?

Accepted Answer

Loss of genetic variation due to a sudden reduction in population size

Population Genetics: Mechanisms of Evolutionary Change

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