Q: A population of 200 plants has the following genotypes: 20 AA, 50 Aa, and 30 aa. What is the frequency of the A allele ($p$) in this population?

$p = \frac{2(20) + 50}{2 \times 100} = 0.45$

Q: A population of plants has the following genotype counts: 16 AA, 63 Aa, and 21 aa. Calculate the frequency of the a allele ($q$).

$q = \frac{2(21) + 63}{2 \times 100} = 0.525$

Question 1

Which of the following is a necessary condition for a population to be in Hardy-Weinberg equilibrium?

Accepted Answer

No gene flow between populations

Question 2

A population of 200 plants has the following genotypes: 20 AA, 50 Aa, and 30 aa. What is the frequency of the A allele ($p$) in this population?

Accepted Answer

$p = \frac{2(20) + 50}{2 	imes 100} = 0.45$

Question 3

Which evolutionary mechanism is the only one that can generate entirely new alleles in a population?

Accepted Answer

Mutation

Question 4

In a small population of birds, a hurricane randomly kills most individuals, leaving only a few survivors. The resulting change in allele frequencies is best described as:

Accepted Answer

Bottleneck effect

Question 5

If a population is undergoing inbreeding but allele frequencies remain unchanged, what is a likely consequence for the population?

Accepted Answer

Decreased heterozygosity and potential inbreeding depression

Question 6

Which of the following best distinguishes genetic drift from natural selection?

Accepted Answer

Genetic drift is a random process, while natural selection is non-random and based on fitness differences.

Question 7

A population of lizards is split by a new river, preventing individuals from crossing. Over time, the two populations develop different allele frequencies. Which mechanism is most likely responsible for the initial divergence?

Accepted Answer

Genetic drift

Question 8

In a population of 200 plants, after several generations of self-fertilization, the number of heterozygotes (Aa) drops from 53 to 15, but the allele frequencies remain at $p = 0.535$ and $q = 0.465$. What does this indicate?

Accepted Answer

No evolution has occurred, but genotype frequencies have changed due to inbreeding.

Question 9

Which scenario best illustrates the founder effect?

Accepted Answer

A few individuals from a mainland bird population colonize a distant island, resulting in a new population with different allele frequencies.

Question 10

Which of the following is an example of intersexual selection?

Accepted Answer

Male peacocks displaying elaborate feathers to attract females.

Question 11

A population of plants has the following genotype counts: 16 AA, 63 Aa, and 21 aa. Calculate the frequency of the a allele ($q$).

Accepted Answer

$q = \frac{2(21) + 63}{2 	imes 100} = 0.525$

Question 12

Which of the following statements about gene flow is correct?

Accepted Answer

Gene flow tends to make populations more genetically similar to each other.

Question 13

Why are small populations more susceptible to genetic drift?

Accepted Answer

Random chance events have a larger impact on allele frequencies in small populations.

Question 14

Which of the following is a potential negative consequence of inbreeding in a population?

Accepted Answer

Increased frequency of deleterious recessive alleles leading to inbreeding depression.

Question 15

A population of fish in a lake is joined by individuals from a nearby river, introducing new alleles. What evolutionary mechanism is at work?

Accepted Answer

Gene flow

Question 16

Which of the following best describes the effect of natural selection on allele frequencies?

Accepted Answer

It increases the frequency of alleles that confer higher fitness.

Question 17

In a population of 200 plants, the genotype frequencies change over time, but the allele frequencies remain constant. Which evolutionary mechanism is most likely at play?

Accepted Answer

Non-random mating (inbreeding)

Question 18

Which of the following is an example of a trade-off associated with sexually selected traits?

Accepted Answer

Brightly colored male birds are more attractive to mates but also more visible to predators.

Question 19

Which of the following statements about mutation is correct?

Accepted Answer

Mutations are random with respect to fitness and are the ultimate source of new alleles.

Question 20

A population of animals is isolated on an island. Over time, the population loses several alleles and becomes genetically uniform. Which process most likely caused this?

Accepted Answer

Genetic drift

Evolutionary Mechanisms and Population Genetics

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