Q: If $$p = 0.7$$ and $$q = 0.3 in a $$population, what is the expected frequency of heterozygotes under Hardy-Weinberg equilibrium?

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

Question 1

Which of the following statements best explains why populations, not individuals, evolve?

Accepted Answer

Evolution acts on the genetic variation present within a population, altering allele frequencies over generations.

Question 2

A population of 500 flowers has two alleles for color: $$C^R ($$red) and $$C^W ($$white). If there are 800 $$C^R$$ alleles and 200 $$C^W$$ alleles, what is the frequency of the $$C^W$$ allele?

Accepted Answer

$$q = \frac{200}{1000} = 0.2$$

Question 3

Which condition is NOT required for a population to be in Hardy-Weinberg equilibrium?

Accepted Answer

Small population size

Question 4

If $$p = 0.7$$ and $$q = 0.3 in a $$population, what is the expected frequency of heterozygotes under Hardy-Weinberg equilibrium?

Accepted Answer

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

Question 5

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

Accepted Answer

Natural selection

Question 6

A population of snakes is separated by a river, and over time, the banding pattern changes in one group due to migration from a neighboring population. Which evolutionary mechanism is most likely responsible?

Accepted Answer

Gene flow

Question 7

In a population of 1000 individuals, if the frequency of allele $$A is$$ $$p = 0.6$$, what is the expected frequency of genotype $$AA$$ under Hardy-Weinberg equilibrium?

Accepted Answer

$$p^2 = 0.36$

Question 8

Which of the following best describes genetic drift?

Accepted Answer

A change in allele frequencies due to random sampling effects, especially in small populations.

Question 9

The founder effect is best illustrated by which scenario?

Accepted Answer

A small group of colonists establishes a new population with different allele frequencies than the original population.

Question 10

If a population is in Hardy-Weinberg equilibrium, what can be concluded about its evolution?

Accepted Answer

The population is not evolving at the locus being studied.

Question 11

Which of the following is an example of disruptive selection?

Accepted Answer

Both extreme phenotypes are favored over intermediate phenotypes.

Question 12

A population of 240 descendants on an island has 4 individuals with a rare genetic disorder. If the original population had 15 colonists, what evolutionary mechanism likely increased the frequency of the disorder?

Accepted Answer

Founder effect

Question 13

Which formula represents the Hardy-Weinberg equation for a gene with two alleles?

Accepted Answer

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

Question 14

Which of the following would most likely disrupt Hardy-Weinberg equilibrium in a population?

Accepted Answer

Small population size

Question 15

Which process creates novel combinations of alleles but does not change allele frequencies in a population?

Accepted Answer

Independent assortment during meiosis

Question 16

A population of 500 flowers has 320 red ($$C^RC^R$$), 160 pink ($$C^RC^W$$), and 20 white ($$C^WC^W) $$individuals. What is the observed frequency of the $$C^RC^W$$ genotype?

Accepted Answer

$$\frac{160}{500} = 0.32$$

Question 17

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

Accepted Answer

Natural selection

Question 18

A population is experiencing a bottleneck event. What is the most likely consequence?

Accepted Answer

Reduced genetic diversity due to a drastic reduction in population size.

Question 19

Which scenario best illustrates gene flow?

Accepted Answer

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

Question 20

Why is genetic variation essential for evolution to occur?

Accepted Answer

It provides the raw material for natural selection to act upon.

Population Genetics: Mechanisms of Evolution in Populations

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