Question 1

Which of the following best describes the bottleneck effect in a population?

Accepted Answer

A sudden reduction in population size due to a random event, leading to loss of genetic variation.

Question 2

A population of birds is separated by a mountain range. Over time, some birds migrate to the other side, introducing new alleles. This scenario is an example of:

Accepted Answer

Gene flow

Question 3

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

Accepted Answer

Small population size

Question 4

If $$p is $$the frequency of allele A and $$q is $$the frequency of allele a in a population, which equation represents the Hardy-Weinberg equilibrium for genotype frequencies?

Accepted Answer

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

Question 5

A population of rabbits experiences a sudden flood, drastically reducing its numbers. The surviving rabbits have less genetic diversity than before. This is an example of:

Accepted Answer

Bottleneck effect

Question 6

Which of the following scenarios best illustrates disruptive selection?

Accepted Answer

A population of fish where both very small and very large individuals are favored over medium-sized ones.

Question 7

Relative fitness is best defined as:

Accepted Answer

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

Question 8

Which process is most likely to increase genetic variation in a population?

Accepted Answer

Mutation

Question 9

A small group of lizards migrates to a new island and establishes a new population. Over generations, the allele frequencies differ from the original population. This is an example of:

Accepted Answer

Founder effect

Question 10

Nonrandom mating in a population will most likely result in:

Accepted Answer

Changes in genotype frequencies but not allele frequencies

Question 11

Which of the following is an example of directional selection?

Accepted Answer

A population of bacteria exposed to antibiotics, where only the most resistant survive.

Question 12

Genetic drift is most likely to have a significant effect in which type of population?

Accepted Answer

Small populations

Question 13

Which of the following statements about mutation is correct?

Accepted Answer

Mutation is the ultimate source of genetic variation.

Question 14

If a population is in Hardy-Weinberg equilibrium, which of the following must be true?

Accepted Answer

Allele frequencies remain constant from generation to generation.

Question 15

Which equation would you use to calculate the frequency of heterozygotes in a population under Hardy-Weinberg equilibrium?

Accepted Answer

$$2pq$$

Question 16

A population of mice has the following allele frequencies: $$p = 0.7$$ and $$q = 0.3. $$What is the expected frequency of homozygous recessive individuals under Hardy-Weinberg equilibrium?

Accepted Answer

$$q^2 = 0.09$

Question 17

Which of the following best describes stabilizing selection?

Accepted Answer

Selection favors individuals with intermediate traits.

Question 18

Which evolutionary mechanism is most likely to decrease genetic variation within a population?

Accepted Answer

Genetic drift

Question 19

A population of insects is exposed to a pesticide. Over time, only those with a specific resistance gene survive and reproduce. This is an example of:

Accepted Answer

Directional selection

Question 20

Which of the following is a direct consequence of gene flow between two populations?

Accepted Answer

Increased similarity in allele frequencies between populations

Population Genetics: Mechanisms of Evolutionary Change

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