Question 1

Which of the following is NOT an assumption of the Hardy–Weinberg equilibrium?

Accepted Answer

Natural selection favors the most fit genotype

Question 2

A population of frogs has genotype frequencies AA = 0.5, Aa = 0.4, and aa = 0.1. If the population is in Hardy–Weinberg equilibrium, what will be the expected frequency of the AA genotype in the next generation?

Accepted Answer

0.5

Question 3

Which of the following best describes the genetic effect of inbreeding in a population?

Accepted Answer

Inbreeding increases homozygosity but does not change allele frequencies.

Question 4

In a population, the genotype AA has $$w = 1.0$$, the heterozygote Aa has $$w = 0.8$$, and aa has $$w = 0.4. $$Which statement best describes what will happen over several generations?

Accepted Answer

The frequency of allele A will increase because it is associated with the highest fitness.

Question 5

Which of the following scenarios best illustrates the founder effect?

Accepted Answer

A small group of individuals colonizes a new island, and their descendants show different allele frequencies than the original population.

Question 6

If the selection coefficient $$s$$ for a genotype is 0.2, what is its relative fitness $$w$$?

Accepted Answer

$$w = 0.8$$

Question 7

Which type of natural selection is most likely to maintain genetic diversity by favoring heterozygotes?

Accepted Answer

Stabilizing selection

Question 8

A population of 1000 organisms has genotype frequencies $$B_1B_1 = 0.36$$, $$B_1B_2 = 0.48$$, and $$B_2B_2 = 0.16. $$After selection, the number of $$B_1B_2$$ individuals is 384. What is the new frequency of $$B_1B_2 in $$the surviving population of 808 individuals?

Accepted Answer

$$0.475$$

Question 9

Which of the following best describes gene flow?

Accepted Answer

Movement of alleles into and out of populations due to migration

Question 10

In the island model of migration, what is the immediate genetic consequence for the admixed population after migration?

Accepted Answer

Allele frequencies change, but the population is not in Hardy–Weinberg equilibrium until after one generation of random mating

Question 11

Which of the following is a likely consequence of a genetic bottleneck?

Accepted Answer

Reduced genetic diversity and possible fixation of alleles

Question 12

A population of bats is initially at Hardy–Weinberg equilibrium with $$S_2S_2$$ genotype frequency of 0.4. After selection, the frequency of $$S_1S_2$$ heterozygotes is 0.349. What is the most likely explanation for this change?

Accepted Answer

Directional selection against $$S_2S_2$$ genotype

Question 13

Which equation correctly represents the Hardy–Weinberg equilibrium for two alleles?

Accepted Answer

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

Question 14

Which of the following is an example of disruptive selection?

Accepted Answer

Selection favors individuals at both extremes of the phenotypic spectrum

Question 15

In a population, the frequency of allele $$A is 0.7 $$and allele $$a is 0.3. $$What is the expected frequency of heterozygotes under Hardy–Weinberg equilibrium?

Accepted Answer

$$0.42$$

Question 16

Which of the following best explains why genetic drift has a greater effect in small populations?

Accepted Answer

Random sampling error is larger in small populations

Question 17

A population undergoes a bottleneck, reducing its size from 1000 to 50. What is the most likely genetic outcome?

Accepted Answer

Some alleles may be lost, and genetic diversity is reduced

Question 18

Which of the following is a requirement for natural selection to cause evolution in a population?

Accepted Answer

Traits must be heritable and affect reproductive success

Question 19

If a deleterious recessive allele is subject to strong selection, what is the expected long-term outcome for its frequency in the population?

Accepted Answer

It will persist at low frequency because it is hidden in heterozygotes

Question 20

Which of the following best describes the difference between the founder effect and a genetic bottleneck?

Accepted Answer

Founder effect involves a new population started by a few individuals; bottleneck involves a drastic reduction in size of an existing population

Population Genetics: Factors Affecting Hardy–Weinberg Equilibrium and Evolutionary Change

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