Question 1

Which mechanism is the only one that consistently leads to adaptive evolution in populations?

Accepted Answer

Natural selection

Question 2

In the Galápagos finch population, what was the primary selective pressure during the 1977 drought?

Accepted Answer

Scarcity of small, soft seeds

Question 3

What is microevolution?

Accepted Answer

Change in allele frequencies in a population over generations

Question 4

Which equation is used to test whether a population is evolving?

Accepted Answer

The Hardy-Weinberg equation: $$p^2 + 2pq$$ + $$q^2 = 1$

Question 5

A population of finches has two alleles for beak size: $$B ($$large) and $$b ($$small). If the frequency of $$B is$$ $$0.7$$ and $$b is$$ $$0.3$$, what is the expected frequency of heterozygotes under Hardy-Weinberg equilibrium?

Accepted Answer

$$0.42$$

Question 6

Which type of selection maintains two or more phenotypes in a population, often through frequency-dependent selection or heterozygote advantage?

Accepted Answer

Balancing selection

Question 7

After the 1977 drought, the average beak depth of finches increased. What does this illustrate?

Accepted Answer

Directional selection

Question 8

Which of the following is a common misconception about evolution?

Accepted Answer

Individual organisms evolve during their lifetime

Question 9

What is the prerequisite for evolution to occur in a population?

Accepted Answer

Genetic variation

Question 10

Which mechanism involves the transfer of alleles between populations?

Accepted Answer

Gene flow

Question 11

A mouse with genotype $$Bb ($$where $$B is $$dominant for black coat and $$b is $$recessive for brown coat) mates with a $$bb$$ mouse. What is the probability that their offspring will have a black coat?

Accepted Answer

$$1/2$$

Question 12

Which of the following mutations would most likely result in a frameshift?

Accepted Answer

A single nucleotide-pair insertion

Question 13

If a population is in Hardy-Weinberg equilibrium, what does this indicate about the population?

Accepted Answer

Allele frequencies are stable from generation to generation

Question 14

Which scenario best illustrates genetic drift?

Accepted Answer

A small population of rabbits is struck by a disease, and only a few survive, randomly changing allele frequencies

Question 15

Which of the following is an example of gene flow?

Accepted Answer

Birds from one population migrate and breed with another population, introducing new alleles

Question 16

What is the effect of stabilizing selection on a population?

Accepted Answer

It favors intermediate phenotypes and reduces variation

Question 17

Which type of selection is most likely to result in speciation?

Accepted Answer

Disruptive selection

Question 18

If the frequency of allele $$A is$$ $$0.6$$ and allele $$a is$$ $$0.4 in a $$population, what is the expected frequency of genotype $$AA$$ under Hardy-Weinberg equilibrium?

Accepted Answer

$$0.36$$

Question 19

Which of the following best describes the impact of natural selection on a population?

Accepted Answer

It consistently increases the frequency of alleles that improve fitness

Question 20

A population of insects is exposed to a new pesticide. Over several generations, the frequency of the allele for pesticide resistance increases. Which mechanism is responsible for this change?

Accepted Answer

Natural selection

The Evolution of Populations: Mechanisms and Evidence

Study Guide - Practice Questions

Study Guide - Flashcards