Q: In a population of 100 individuals, 40 have curly hair (AA), 30 have wavy hair (Aa), and 30 have straight hair (aa). What is the frequency of the A allele?

$$\frac{40 \times 2 + 30}{200} = \frac{110}{200} = 0.55$$

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

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

Q: A population of 200 people has allele frequencies $$p = 0.6$$ and $$q = 0.4. $$How many individuals are expected to be homozygous recessive ($$q^2) $$under Hardy-Weinberg equilibrium?

$$q^2$$ \times 200 = 0.16 \times 200 = 32$$

Q: A population of 1000 individuals has a recessive allele frequency $$q = 0.2. $$What is the expected number of heterozygotes ($$2pq) $$under Hardy-Weinberg equilibrium?

$$2 \times 0.8 \times 0.2 \times 1000 = 320$$

Question 1

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

Accepted Answer

Non-random mating

Question 2

In a population of 100 individuals, 40 have curly hair (AA), 30 have wavy hair (Aa), and 30 have straight hair (aa). What is the frequency of the A allele?

Accepted Answer

$$\frac{40 	imes 2 + 30}{200} = \frac{110}{200} = 0.55$$

Question 3

Which equation correctly represents the Hardy-Weinberg principle for genotype frequencies?

Accepted Answer

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

Question 4

A population is found to have 100 people with wavy hair (Aa), 75 with curly hair (AA), and 25 with straight hair (aa). Is this population in Hardy-Weinberg equilibrium?

Accepted Answer

No, because the observed genotype frequencies do not match those predicted by Hardy-Weinberg.

Question 5

Which of the following mechanisms can cause evolution in a population by changing allele frequencies?

Accepted Answer

All of the above

Question 6

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 7

Which scenario best illustrates the founder effect?

Accepted Answer

A small group of individuals colonizes a new island, and their allele frequencies differ from the original population.

Question 8

Why is random mating important for Hardy-Weinberg equilibrium?

Accepted Answer

It ensures that genotype frequencies are determined only by allele frequencies.

Question 9

Which type of selection maintains genetic variation by favoring heterozygotes?

Accepted Answer

Heterozygote advantage

Question 10

A population of 200 people has allele frequencies $$p = 0.6$$ and $$q = 0.4. $$How many individuals are expected to be homozygous recessive ($$q^2) $$under Hardy-Weinberg equilibrium?

Accepted Answer

$$q^2$$ 	imes 200 = 0.16 	imes 200 = 32$$

Question 11

Which of the following is an example of frequency-dependent selection?

Accepted Answer

The fitness of a phenotype depends on how common it is in the population.

Question 12

Why are perfect adaptations rarely achieved in evolution?

Accepted Answer

Evolution is limited by historical constraints, trade-offs, and genetic variation.

Question 13

If a population is in Hardy-Weinberg equilibrium, what will happen to allele frequencies over generations?

Accepted Answer

They will remain constant.

Question 14

Which factor is most likely to disrupt Hardy-Weinberg equilibrium in a small population?

Accepted Answer

Genetic drift

Question 15

A population of 1000 individuals has a recessive allele frequency $$q = 0.2. $$What is the expected number of heterozygotes ($$2pq) $$under Hardy-Weinberg equilibrium?

Accepted Answer

$$2 	imes 0.8 	imes 0.2 	imes 1000 = 320$$

Question 16

Which of the following best describes genetic drift?

Accepted Answer

Random changes in allele frequencies due to chance events

Question 17

In a population, the frequency of the dominant allele ($$p) is 0.3. $$What is the frequency of the recessive allele ($$q$$)?

Accepted Answer

$$q = 1 - p = 0.7$$

Question 18

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

Accepted Answer

Genotype frequencies deviate from Hardy-Weinberg expectations

Question 19

A population of 500 individuals has 5 people with a rare recessive phenotype. What is the frequency of the recessive allele ($$q$$)?

Accepted Answer

$$q = \sqrt{\frac{5}{500}} = \sqrt{0.01} = 0.1$$

Question 20

Which of the following is an example of gene flow?

Accepted Answer

Individuals migrate from one population to another, introducing new alleles.

Population Genetics and Hardy-Weinberg Equilibrium: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards