BIOL 101 Week 7 Quiz V3 | BIOL 101 Principles of
Biology | Actual Q&A with Rationale (BIOL101
Week 7 Quiz) | Liberty University
1. What is the primary mechanism of adaptive evolution proposed by Charles Darwin?
A. Genetic drift
B. Gene flow
C. Mutation
D. Natural selection
Correct Answer: D
Explanation: Natural selection is the process by which individuals with inherited traits
better suited to their environment tend to survive and reproduce more successfully. Over
time, this results in the accumulation of favorable traits in the population. While genetic
drift and mutations also influence evolution, natural selection is the only mechanism that
consistently leads to adaptation.
2. Which concept refers to the total collection of genes in a population at any one time?
A. Genotype
B. Gene pool
C. Phenotype
D. Genome
,Correct Answer: B
Explanation: The gene pool consists of all the alleles for all loci in all individuals of a
population. It serves as the genetic reservoir from which the next generation draws its
genes. Understanding the gene pool is essential for tracking microevolutionary changes
within a specific group.
3. A sudden reduction in population size due to a natural disaster is known as:
A. The bottleneck effect
B. The founder effect
C. Disruptive selection
D. Gene flow
Correct Answer: A
Explanation: The bottleneck effect occurs when a catastrophic event drastically reduces
the size of a population. Because the survivors are a random sample of the original
population, certain alleles may be overrepresented or lost entirely. This process
significantly decreases the genetic diversity of the surviving group.
4. Which type of selection favors individuals at both extremes of a phenotypic range?
A. Directional selection
B. Stabilizing selection
C. Sexual selection
, D. Disruptive selection
Correct Answer: D
Explanation: Disruptive selection occurs when environmental conditions favor individuals
on both ends of the phenotypic spectrum over intermediate phenotypes. This can
eventually lead to a split in the population if the two groups stop interbreeding. It is a key
mechanism for increasing biological diversity within a single lineage.
5. The movement of alleles between populations through migration is called:
A. Genetic drift
B. Artificial selection
C. Speciation
D. Gene flow
Correct Answer: D
Explanation: Gene flow is the transfer of alleles from one population to another due to the
movement of individuals or gametes. This process tends to reduce genetic differences
between populations, making them more similar over time. In some cases, it can introduce
new genetic variation that was not previously present.
6. Structures that are similar in different species because of common ancestry are called:
A. Homologous structures
B. Analogous structures
Biology | Actual Q&A with Rationale (BIOL101
Week 7 Quiz) | Liberty University
1. What is the primary mechanism of adaptive evolution proposed by Charles Darwin?
A. Genetic drift
B. Gene flow
C. Mutation
D. Natural selection
Correct Answer: D
Explanation: Natural selection is the process by which individuals with inherited traits
better suited to their environment tend to survive and reproduce more successfully. Over
time, this results in the accumulation of favorable traits in the population. While genetic
drift and mutations also influence evolution, natural selection is the only mechanism that
consistently leads to adaptation.
2. Which concept refers to the total collection of genes in a population at any one time?
A. Genotype
B. Gene pool
C. Phenotype
D. Genome
,Correct Answer: B
Explanation: The gene pool consists of all the alleles for all loci in all individuals of a
population. It serves as the genetic reservoir from which the next generation draws its
genes. Understanding the gene pool is essential for tracking microevolutionary changes
within a specific group.
3. A sudden reduction in population size due to a natural disaster is known as:
A. The bottleneck effect
B. The founder effect
C. Disruptive selection
D. Gene flow
Correct Answer: A
Explanation: The bottleneck effect occurs when a catastrophic event drastically reduces
the size of a population. Because the survivors are a random sample of the original
population, certain alleles may be overrepresented or lost entirely. This process
significantly decreases the genetic diversity of the surviving group.
4. Which type of selection favors individuals at both extremes of a phenotypic range?
A. Directional selection
B. Stabilizing selection
C. Sexual selection
, D. Disruptive selection
Correct Answer: D
Explanation: Disruptive selection occurs when environmental conditions favor individuals
on both ends of the phenotypic spectrum over intermediate phenotypes. This can
eventually lead to a split in the population if the two groups stop interbreeding. It is a key
mechanism for increasing biological diversity within a single lineage.
5. The movement of alleles between populations through migration is called:
A. Genetic drift
B. Artificial selection
C. Speciation
D. Gene flow
Correct Answer: D
Explanation: Gene flow is the transfer of alleles from one population to another due to the
movement of individuals or gametes. This process tends to reduce genetic differences
between populations, making them more similar over time. In some cases, it can introduce
new genetic variation that was not previously present.
6. Structures that are similar in different species because of common ancestry are called:
A. Homologous structures
B. Analogous structures
