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

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

Q: In a population, the frequency of allele D is 0.5. What is the expected frequency of heterozygotes (Dd) under Hardy-Weinberg equilibrium?

$$2pq = 2 \times 0.5 \times 0.5 = 0.5$$

Question 1

Which of the following is NOT an assumption of the Hardy-Weinberg equilibrium?

Accepted Answer

Natural selection favors certain genotypes.

Question 2

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

Accepted Answer

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

Question 3

A population of flowers has two alleles for petal color: R (red) and r (white). If 16% of the population is white (rr), what is the frequency of the r allele?

Accepted Answer

$$q = \sqrt{0.16} = 0.4$$

Question 4

Which scenario would most likely cause a population to deviate from Hardy-Weinberg equilibrium?

Accepted Answer

A disease kills only individuals with a specific genotype.

Question 5

In a population, the frequency of allele B is 0.2. What is the expected frequency of homozygous dominant individuals (BB) under Hardy-Weinberg equilibrium?

Accepted Answer

$$q^2$$ = $$(0.2)^2 = 0.04$

Question 6

Which of the following best describes a gene pool?

Accepted Answer

The total set of alleles present in all individuals of a population.

Question 7

If a population is in Hardy-Weinberg equilibrium, what will happen to allele frequencies from one generation to the next?

Accepted Answer

They will remain constant.

Question 8

Which of the following is an example of genetic drift?

Accepted Answer

A hurricane randomly kills half the population, regardless of genotype.

Question 9

A population of 1000 individuals has 360 homozygous recessive (aa) individuals. What is the frequency of the dominant allele (A)?

Accepted Answer

$$q^2 = 0.36$$ \rightarrow q = 0.6 \rightarrow p = 1 - 0.6 = 0.4$$

Question 10

Which of the following would NOT cause a change in allele frequencies in a population?

Accepted Answer

Random mating

Question 11

If a population violates the assumption of no migration, what is the likely effect on allele frequencies?

Accepted Answer

Allele frequencies may change due to gene flow.

Question 12

Which of the following is a real-world application of the Hardy-Weinberg equation?

Accepted Answer

Estimating the frequency of carriers for a genetic disease in a population.

Question 13

In a population, the frequency of allele D is 0.5. What is the expected frequency of heterozygotes (Dd) under Hardy-Weinberg equilibrium?

Accepted Answer

$$2pq = 2 	imes 0.5 	imes 0.5 = 0.5$$

Question 14

Which of the following statements about allele frequencies is TRUE?

Accepted Answer

Allele frequencies can change due to random sampling error in small populations.

Question 15

A population of beetles has two alleles for shell color: G (green) and g (brown). If 49% of the population is green (GG), what is the frequency of the G allele?

Accepted Answer

$$p^2 = 0.49$$ \rightarrow p = 0.7$$

Question 16

Which of the following would be considered a violation of Hardy-Weinberg equilibrium?

Accepted Answer

A mutation introduces a new allele into the population.

Question 17

If 9% of a population expresses a recessive phenotype, what is the frequency of the dominant allele?

Accepted Answer

$$q^2 = 0.09$$ \rightarrow q = 0.3 \rightarrow p = 1 - 0.3 = 0.7$$

Question 18

Which of the following best explains why harmful recessive alleles can persist in a population?

Accepted Answer

They are carried by healthy heterozygotes who do not express the harmful phenotype.

Question 19

A population is found to have the following genotype frequencies: AA = 0.36, Aa = 0.48, aa = 0.16. Is this population in Hardy-Weinberg equilibrium?

Accepted Answer

Yes, because $$p^2 = 0.36$, 2pq = 0.48$, q^2$ = 0.16$$ and $$p + q = 1.$$

Question 20

Which of the following is a consequence of non-random mating in a population?

Accepted Answer

Genotype frequencies may change, but allele frequencies may remain the same.

Population Genetics and Hardy-Weinberg Equilibrium

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