Q: In a population at Hardy-Weinberg equilibrium, the frequency of allele $$A is$$ $$p = 0.7$$ and the frequency of allele $$a is$$ $$q = 0.3. $$What is the expected frequency of heterozygotes ($$Aa$$)?

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

Question 1

Which of the following best describes the gene pool of a population?

Accepted Answer

All the alleles for every gene present in all individuals of a population.

Question 2

A population of 500 diploid plants has the following genotypes for flower color: 320 red (C	extsuperscript{R}C	extsuperscript{R}), 20 white (C	extsuperscript{W}C	extsuperscript{W}), and 160 pink (C	extsuperscript{R}C	extsuperscript{W}). What is the frequency of the C	extsuperscript{R} allele in the population?

Accepted Answer

$$p = \frac{800}{1000} = 0.8$$

Question 3

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

Accepted Answer

Natural selection favors the most common phenotype.

Question 4

In a population at Hardy-Weinberg equilibrium, the frequency of allele $$A is$$ $$p = 0.7$$ and the frequency of allele $$a is$$ $$q = 0.3. $$What is the expected frequency of heterozygotes ($$Aa$$)?

Accepted Answer

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

Question 5

Which scenario best illustrates the bottleneck effect?

Accepted Answer

A disease outbreak kills most of a population, leaving only a few survivors with random alleles.

Question 6

Which of the following is a direct consequence of gene flow between two populations?

Accepted Answer

Reduced genetic differences between populations.

Question 7

A recessive genetic disorder occurs in 1 out of 10,000 births. Assuming Hardy-Weinberg equilibrium, what is the frequency of the recessive allele ($$q$$)?

Accepted Answer

$$q = \sqrt{1/10,000} = 0.01$$

Question 8

Which of the following is an example of genetic drift?

Accepted Answer

A population of beetles where a few individuals are randomly killed by a storm, changing allele frequencies.

Question 9

Which process is most likely to cause a harmful allele to become fixed in a small population?

Accepted Answer

Genetic drift

Question 10

Which of the following best explains why sexual reproduction increases genetic variation in a population?

Accepted Answer

It combines alleles in new ways through independent assortment and random fertilization.

Question 11

A population of plants has two alleles for flower color: $$R ($$red) and $$r ($$white). If $$p = 0.6$$ and $$q = 0.4$$, what is the expected frequency of white-flowered plants ($$rr) $$under Hardy-Weinberg equilibrium?

Accepted Answer

$$q^2 = 0.16$

Question 12

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

Accepted Answer

Directional selection

Question 13

Which of the following statements about natural selection is correct?

Accepted Answer

Natural selection increases the frequency of beneficial alleles over generations.

Question 14

A population of animals is isolated from others and experiences no gene flow. Which Hardy-Weinberg condition is being met?

Accepted Answer

Isolated population

Question 15

Which of the following is an example of the founder effect?

Accepted Answer

A few individuals from a population colonize a new island, resulting in different allele frequencies compared to the original population.

Question 16

Which of the following would violate the assumptions of Hardy-Weinberg equilibrium?

Accepted Answer

Natural selection favoring a specific allele

Question 17

If a population is not in Hardy-Weinberg equilibrium, what can you conclude?

Accepted Answer

At least one of the Hardy-Weinberg assumptions is being violated.

Question 18

Which of the following is a real-world example of gene flow?

Accepted Answer

Pollen from one population of plants fertilizes plants in a neighboring population.

Question 19

Which of the following best describes microevolution?

Accepted Answer

The change in allele frequencies in a population over time.

Question 20

Which of the following is most likely to increase genetic variation in a population?

Accepted Answer

Gene flow

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