Q: In a population of 1000 individuals, the frequency of allele $A$ is $p = 0.7$ and the frequency of allele $a$ is $q = 0.3$. According to Hardy-Weinberg equilibrium, what is the expected frequency of heterozygotes ($Aa$)?

$2pq = 2 \times 0.7 \times 0.3 = 0.42$

Question 1

Which of the following best distinguishes microevolution from macroevolution?

Accepted Answer

Microevolution refers to changes in allele frequencies within a population over generations, while macroevolution refers to broad patterns of evolutionary change above the species level.

Question 2

Which of the following is NOT a mechanism that can cause evolution in populations?

Accepted Answer

Mitosis

Question 3

In the statement, '___________ acts on individuals but only ___________ evolve,' which words correctly fill the blanks?

Accepted Answer

Natural selection; populations

Question 4

Why is genetic variation essential for evolution to occur in a population?

Accepted Answer

It provides the raw material upon which natural selection can act.

Question 5

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

Accepted Answer

Mitosis in somatic cells

Question 6

A population is defined as:

Accepted Answer

A group of individuals of the same species living in the same area and interbreeding.

Question 7

The gene pool of a population is best described as:

Accepted Answer

All the alleles for all genes in all individuals of the population.

Question 8

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

Accepted Answer

Small population size

Question 9

In a population of 1000 individuals, the frequency of allele $A$ is $p = 0.7$ and the frequency of allele $a$ is $q = 0.3$. According to Hardy-Weinberg equilibrium, what is the expected frequency of heterozygotes ($Aa$)?

Accepted Answer

$2pq = 2 	imes 0.7 	imes 0.3 = 0.42$

Question 10

Which scenario best illustrates genetic drift?

Accepted Answer

A hurricane randomly kills most of a population, leaving only a few survivors with different allele frequencies than the original population.

Question 11

Which of the following is NOT one of the four effects of genetic drift discussed in lecture?

Accepted Answer

It increases genetic variation within populations.

Question 12

Natural selection is best described as:

Accepted Answer

A non-random process that increases the frequency of beneficial alleles in a population.

Question 13

Which of the following is an example of gene flow?

Accepted Answer

A group of wolves migrates into a new area and breeds with the local population, introducing new alleles.

Question 14

Which of the following best defines adaptive radiation?

Accepted Answer

The rapid evolution of diversely adapted species from a common ancestor.

Question 15

Sexual selection can result in:

Accepted Answer

The evolution of traits that improve mating success, even if they reduce survival.

Question 16

A population of beetles has two alleles for color: $G$ (green) and $g$ (brown). If the frequency of $G$ is $0.4$ and the population is in Hardy-Weinberg equilibrium, what is the expected frequency of brown beetles ($gg$)?

Accepted Answer

$q^2 = (1 - 0.4)^2 = 0.36$

Question 17

Which of the following real-world scenarios best illustrates the founder effect, a type of genetic drift?

Accepted Answer

A small group of humans colonizes an isolated island, and their descendants have different allele frequencies than the original population.

Question 18

If a population is not in Hardy-Weinberg equilibrium, what can you conclude?

Accepted Answer

At least one of the five Hardy-Weinberg conditions is not being met, and the population is evolving.

Question 19

Which of the following statements about natural selection is correct?

Accepted Answer

Natural selection increases the frequency of alleles that enhance survival and reproduction.

Question 20

A scientist observes that a population of finches on an island has developed different beak shapes after a drought, allowing them to exploit new food sources. This is an example of:

Accepted Answer

Adaptive radiation

Study Guide: Evolutionary Mechanisms and Population Genetics

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