Question 1

Which of the following best explains why genetic variation is necessary for natural selection to occur in a population?

Accepted Answer

Genetic variation provides different traits that may confer a survival or reproductive advantage under changing environmental conditions.

Question 2

A population of 100 plants has the following genotype counts for a flower color gene: 25 red (CRCR), 50 pink (CRCW), and 25 white (CWCW). What is the frequency of the CW allele in this population? Use the formula $$	ext{Frequency of CW} = \frac{2 	imes 	ext{CWCW} + 	ext{CRCW}}{2 	imes 	ext{Total individuals}}.$$

Accepted Answer

$$0.50$$

Question 3

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

Accepted Answer

Small population size

Question 4

In a population of humans, the allele frequency of the dominant earwax allele (E) is $$0.8. $$What is the frequency of the recessive allele (e)?

Accepted Answer

$$0.2$$

Question 5

If a population is in Hardy-Weinberg equilibrium and the frequency of the dominant allele $$p is$$ $$0.6$$, what is the expected frequency of heterozygotes? Use the formula $$2pq$$ where $$q = 1 - p.$$

Accepted Answer

$$0.48$$

Question 6

Which pattern of natural selection is illustrated when individuals with intermediate phenotypes have higher fitness than those with extreme phenotypes?

Accepted Answer

Stabilizing selection

Question 7

A population of birds experiences a sudden environmental event that drastically reduces its size. The surviving birds have different allele frequencies than the original population. What is this scenario called?

Accepted Answer

Bottleneck effect

Question 8

Which of the following best describes genetic drift?

Accepted Answer

A change in allele frequencies due to random chance, especially in small populations

Question 9

In a population affected by malaria, individuals who are heterozygous for the sickle cell allele (HbA HbS) have a survival advantage. What type of selection is this?

Accepted Answer

Balancing selection (heterozygote advantage)

Question 10

Which of the following scenarios is an example of intersexual selection?

Accepted Answer

Female peacocks choosing males with the brightest tail feathers

Question 11

A small group of individuals separates from a larger population and establishes a new colony. The allele frequencies in the new colony differ from the original population. What is this called?

Accepted Answer

Founder effect

Question 12

Which evolutionary process tends to reduce differences in allele frequencies between two populations?

Accepted Answer

Migration (gene flow)

Question 13

If $$p^2 = 0.36$ in a population at Hardy-Weinberg equilibrium, what is the frequency of the dominant allele p$?

Accepted Answer

$$0.6$$

Question 14

Which of the following is a real-world example of directional selection?

Accepted Answer

Increase in frequency of antibiotic-resistant bacteria after exposure to antibiotics

Question 15

Which of the following would violate the assumption of random mating in Hardy-Weinberg equilibrium?

Accepted Answer

Individuals preferentially mate with those of similar phenotype

Question 16

In a population, the fitness of a phenotype depends on how common it is, with rare phenotypes having higher fitness. What is this called?

Accepted Answer

Frequency-dependent selection

Question 17

Which of the following is most likely to increase genetic diversity within a population?

Accepted Answer

Migration (gene flow) from other populations

Question 18

A population of 200 individuals has 32 homozygous recessive individuals for a trait. Assuming Hardy-Weinberg equilibrium, what is the frequency of the recessive allele $$q$$? Use $$q^2$$ = \frac{32}{200}$$.

Accepted Answer

$$0.4$$

Question 19

Which of the following statements about genetic drift is TRUE?

Accepted Answer

Genetic drift can lead to the fixation or loss of alleles more rapidly in small populations.

Question 20

Which process is most likely responsible for the evolution of darker colored peppered moths in polluted environments, as shown in the provided image?

Accepted Answer

Directional selection

Evolution of Populations: Population Genetics and Mechanisms of Evolution

Study Guide - Practice Questions

Study Guide - Flashcards