Q: In a population of snapdragons, there are 80 plants with red flowers (RR), 240 with pink flowers (Rr), and 180 with white flowers (rr). What is the frequency of the r allele in this population?

$$f(r) = \frac{240 + 2 \times 180}{2 \times 500} = 0.6$$

Q: A population of 1000 individuals has the following genotype counts: 490 AA, 420 Aa, and 90 aa. What is the frequency of the A allele?

$$f(A) = \frac{490 + 0.5 \times 420}{1000} = 0.7$$

Q: If the frequency of allele A ($$p) in a $$population is 0.3, what is the expected frequency of heterozygotes (Aa) under Hardy-Weinberg equilibrium?

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

Q: In a population, the frequency of allele B is 0.8. What is the expected frequency of individuals with genotype Bb under Hardy-Weinberg equilibrium?

$$2pq = 2 \times 0.8 \times 0.2 = 0.32$$

Q: A population of 600 individuals has 200 RR, 300 Rr, and 100 rr. Calculate the frequency of the R allele.

$$f(R) = \frac{2 \times 200 + 300}{2 \times 600} = 0.5$$

Question 1

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

Accepted Answer

Mating must be random among individuals.

Question 2

In a population of snapdragons, there are 80 plants with red flowers (RR), 240 with pink flowers (Rr), and 180 with white flowers (rr). What is the frequency of the r allele in this population?

Accepted Answer

$$f(r) = \frac{240 + 2 	imes 180}{2 	imes 500} = 0.6$$

Question 3

Which of the following best describes genetic variation?

Accepted Answer

Differences in DNA sequences among individuals within a population.

Question 4

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

Accepted Answer

Cloning of individuals

Question 5

A population of 1000 individuals has the following genotype counts: 490 AA, 420 Aa, and 90 aa. What is the frequency of the A allele?

Accepted Answer

$$f(A) = \frac{490 + 0.5 	imes 420}{1000} = 0.7$$

Question 6

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

Accepted Answer

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

Question 7

If the frequency of allele A ($$p) in a $$population is 0.3, what is the expected frequency of heterozygotes (Aa) under Hardy-Weinberg equilibrium?

Accepted Answer

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

Question 8

Which of the following would cause a population to deviate from Hardy-Weinberg equilibrium?

Accepted Answer

Non-random mating

Question 9

A population is in Hardy-Weinberg equilibrium with allele frequencies $$p = 0.4$$ and $$q = 0.6. $$What is the expected frequency of the homozygous recessive genotype?

Accepted Answer

$$q^2 = 0.36$

Question 10

Which of the following statements about allele frequency is correct?

Accepted Answer

Allele frequency is the proportion of a specific allele among all alleles for a gene in a population.

Question 11

In a population, the frequency of allele B is 0.8. What is the expected frequency of individuals with genotype Bb under Hardy-Weinberg equilibrium?

Accepted Answer

$$2pq = 2 	imes 0.8 	imes 0.2 = 0.32$$

Question 12

Which of the following is a consequence of genetic variation in a population?

Accepted Answer

The population will have a greater ability to adapt to environmental changes.

Question 13

A population of 600 individuals has 200 RR, 300 Rr, and 100 rr. Calculate the frequency of the R allele.

Accepted Answer

$$f(R) = \frac{2 	imes 200 + 300}{2 	imes 600} = 0.5$$

Question 14

Which of the following is an example of genetic recombination?

Accepted Answer

Crossing over during meiosis

Question 15

If a population is not in Hardy-Weinberg equilibrium, which of the following could be a possible explanation?

Accepted Answer

Natural selection is acting on the population.

Question 16

Which of the following best defines genotypic frequency?

Accepted Answer

The proportion of a specific genotype among all individuals in a population.

Question 17

A population of 1000 individuals has 360 AA, 480 Aa, and 160 aa. What is the frequency of the a allele?

Accepted Answer

$$f(a) = \frac{2 	imes 160 + 480}{2 	imes 1000} = 0.4$$

Question 18

Which of the following is a characteristic of a population in Hardy-Weinberg equilibrium?

Accepted Answer

Allele and genotypic frequencies remain constant from generation to generation.

Question 19

In a population, the frequency of allele C is 0.25. What is the expected frequency of genotype CC under Hardy-Weinberg equilibrium?

Accepted Answer

$$p^2$$ = $$0.25^2 = 0.0625$

Question 20

Which of the following real-world scenarios would most likely result in a population NOT being in Hardy-Weinberg equilibrium?

Accepted Answer

A population of birds where a disease kills only individuals with a specific genotype.

Population Genetics and the Hardy-Weinberg Principle

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