Question 1

According to Darwin, what is the primary mechanism for evolutionary change in populations?

Accepted Answer

Natural selection

Question 2

Which of the following best describes genetic variation?

Accepted Answer

Differences among individuals in the composition of their genes or DNA sequences

Question 3

A population of wild horses shows a range of coat colors. This variation is most likely due to:

Accepted Answer

Genetic variation influenced by multiple genes

Question 4

Which of the following statements about mutations is correct?

Accepted Answer

Mutations can create new alleles by changing the nucleotide sequence of DNA

Question 5

A base-pair substitution in a gene may have no effect on the protein produced. This is most likely because:

Accepted Answer

The substitution occurs in a region that does not change the amino acid sequence

Question 6

Which equation represents the Hardy-Weinberg equilibrium for allele frequencies?

Accepted Answer

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

Question 7

Which process increases genetic variation in sexually reproducing populations?

Accepted Answer

Crossing over during meiosis

Question 8

If a population stopped reproducing sexually and only reproduced asexually, what would happen to its genetic variation over time?

Accepted Answer

Genetic variation would decrease due to lack of recombination

Question 9

Which of the following is an example of environmentally induced phenotypic variation?

Accepted Answer

A caterpillar changing its appearance based on the type of plant it feeds on

Question 10

Large-scale changes in gene number, such as the proliferation of olfactory receptor genes in mammals, are most likely caused by:

Accepted Answer

Gene duplication events

Question 11

Why do most mutations in noncoding regions of DNA not affect an organism's phenotype?

Accepted Answer

Because they do not alter the amino acid sequence of proteins

Question 12

Which mechanism is responsible for the random distribution of alleles into gametes during meiosis?

Accepted Answer

Independent assortment

Question 13

HIV has a high mutation rate because:

Accepted Answer

It has an RNA genome and lacks efficient RNA repair mechanisms

Question 14

Which of the following best explains why some mutations are neutral?

Accepted Answer

They do not change the function of the protein encoded by the gene

Question 15

What is the effect of crossing over during meiosis?

Accepted Answer

It increases genetic variation by exchanging alleles between homologous chromosomes

Question 16

Which of the following is a plausible outcome of a deletion mutation in a gene?

Accepted Answer

Loss of function of the protein encoded by the gene

Question 17

Which process typically brings together gametes that have different genetic backgrounds?

Accepted Answer

Random fertilization

Question 18

A population with a large pool of alleles is more likely to:

Accepted Answer

Adapt to environmental changes

Question 19

Which of the following is NOT a source of genetic variation in populations?

Accepted Answer

Binary fission

Question 20

Which scenario best illustrates the concept of heritable phenotypic variation?

Accepted Answer

A child inherits blood type A from one parent and blood type O from the other

Genetic Variation and Its Role in Evolution

Study Guide - Practice Questions