BIOL 210 Module 8: Population Genetics and Evolutionary Processes Updated and Latest Questions and Correct Answers with Rationale

BIOL 210 Module 8: Population Genetics and
Evolutionary Processes Updated and Latest
Questions and Correct Answers with Rationale
1. Which of the following terms describes the total aggregate of all alleles for all loci in all
individuals within a population?
A. Genetic drift

B. Genome

C. Genotype

D. Gene pool

Correct Answer: D
Explanation: The gene pool represents the entire collection of alleles in a population. A
genome refers to the individual’s genetic makeup, while genetic drift is a process of change.

2. In the Hardy-Weinberg equation, p^2 represents the frequency of which genotype?
A. Homozygous recessive

B. Heterozygous

C. Phenotypic dominant

D. Homozygous dominant
Correct Answer: D
Explanation: In the equation p^2 + 2pq + q^2 = 1, p represents the frequency of the
dominant allele; therefore, p^2 is the frequency of the homozygous dominant genotype.

3. If the frequency of a recessive allele (q) in a population is 0.4, what is the frequency of the
dominant allele (p)?
A. 0.16

B. 0.36

C. 0.6

D. 0.4

Correct Answer: C
Explanation: Since p + q = 1, if q is 0.4, then p must be 1 - 0.4 = 0.6.

,4. Which condition is NOT a requirement for a population to be in Hardy-Weinberg
equilibrium?
A. No mutations

B. No natural selection

C. Random mating

D. Small population size
Correct Answer: D
Explanation: Hardy-Weinberg equilibrium requires an extremely large population size to
minimize the effects of genetic drift. Small populations are more likely to undergo
evolutionary changes.

5. A population of 100 individuals has 16 individuals with the recessive phenotype (aa). What
is the frequency of the ‘a’ allele (q)?
A. 0.4

B. 0.84

C. 0.16

D. 0.04
Correct Answer: A
Explanation: The frequency of the recessive phenotype (q^2) is 16/100 = 0.16. To find q,
take the square root of 0.16, which is 0.4.

6. Which evolutionary force is primarily responsible for introducing new alleles into a
population’s gene pool?
A. Natural selection

B. Genetic drift

C. Mutation

D. Gene flow

Correct Answer: C
Explanation: Mutation is the ultimate source of all new genetic variation. Gene flow moves
existing alleles, and selection/drift change existing frequencies.

7. What occurs during the ‘founder effect’?
A. A few individuals start a new colony with a different allele frequency than the original
population

B. A population is reduced to a small size by a natural disaster

, C. Alleles move between two existing populations

D. Individuals with certain traits are more likely to survive and reproduce
Correct Answer: A
Explanation: The founder effect is a type of genetic drift where a small group breaks off
from a larger population to establish a new one, carrying only a fraction of the original
genetic diversity.

8. If the frequency of the homozygous dominant genotype is 0.49, what is the frequency of
the heterozygotes in a population at Hardy-Weinberg equilibrium?
A. 0.51

B. 0.7

C. 0.09

D. 0.42

Correct Answer: D
Explanation: If p^2 = 0.49, then p = 0.7. This means q = 0.3 (1 - 0.7). The frequency of
heterozygotes is 2pq = 2 * 0.7 * 0.3 = 0.42.

9. Which type of selection favors individuals at both extremes of a phenotypic range over
intermediate phenotypes?
A. Directional selection

B. Stabilizing selection

C. Disruptive selection

D. Artificial selection
Correct Answer: C
Explanation: Disruptive (or diversifying) selection favors both extremes, potentially
leading to two distinct groups. Stabilizing favors the middle, and directional favors one end.

10. In a population where p = 0.8 and q = 0.2, what is the frequency of the homozygous
recessive genotype?
A. 0.04

B. 0.32

C. 0.64

D. 0.2

Correct Answer: A