Q: In a population of 700 individuals, there are 85 with genotype AA, 320 with genotype Aa, and 295 with genotype aa. What is the frequency of the dominant allele ($$p$$)?

$$p = \frac{85 + 0.5 \times 320}{700}$$

Question 1

Which of the following best explains why individuals do not evolve, but populations do?

Accepted Answer

Evolution refers to changes in allele frequencies within a population over generations, not within a single individual.

Question 2

A population of 100 pea plants contains 9 individuals with the homozygous recessive genotype (short plants). Assuming Hardy-Weinberg equilibrium, what is the frequency of the recessive allele ($$q$$)?

Accepted Answer

$$q = 0.3$$

Question 3

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

Accepted Answer

Natural selection favoring certain traits

Question 4

Which scenario best illustrates the bottleneck effect?

Accepted Answer

A population of deer is drastically reduced by a forest fire, leaving only a few survivors to repopulate.

Question 5

In a population of 700 individuals, there are 85 with genotype AA, 320 with genotype Aa, and 295 with genotype aa. What is the frequency of the dominant allele ($$p$$)?

Accepted Answer

$$p = \frac{85 + 0.5 	imes 320}{700}$$

Question 6

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

Accepted Answer

No mutations

Question 7

A particular genetic disorder is caused by a recessive allele. If the prevalence of affected individuals is 1 in 6,600, what is the approximate frequency of carriers in the population, assuming Hardy-Weinberg equilibrium?

Accepted Answer

0.02430

Question 8

Which of the following best describes gene flow?

Accepted Answer

Interbreeding between populations, resulting in the movement of alleles

Question 9

If $$p = 0.7$$ and $$q = 0.3 in a $$population, what is the expected frequency of heterozygotes ($$2pq) $$under Hardy-Weinberg equilibrium?

Accepted Answer

$$2pq = 0.42$$

Question 10

Which of the following is an example of nonrandom mating affecting evolution?

Accepted Answer

A population where individuals mate based on physical attractiveness, leading to sexual selection.

Question 11

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

Accepted Answer

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

Question 12

A researcher observes that the allele frequencies in a population have changed over several generations. Which evolutionary process does this best illustrate?

Accepted Answer

Microevolution

Question 13

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

Accepted Answer

Gene flow from another population

Question 14

Which of the following statements about natural selection is TRUE?

Accepted Answer

Natural selection acts on existing variation and is influenced by environmental factors.

Question 15

If a population is in Hardy-Weinberg equilibrium, what can be inferred about the population?

Accepted Answer

Allele frequencies remain constant from one generation to the next.

Question 16

Which of the following is a consequence of the founder effect?

Accepted Answer

Rare alleles may become common in a new, isolated population.

Question 17

A population of fish is isolated in a small pond after a flood. Over time, rare alleles become more common. Which evolutionary mechanism is most likely responsible?

Accepted Answer

Genetic drift

Question 18

Which of the following would violate the conditions required for Hardy-Weinberg equilibrium?

Accepted Answer

Gene flow between populations

Question 19

Why is rapid reproduction in organisms like HIV a source of genetic variation?

Accepted Answer

It allows for more mutations to occur in a shorter time, increasing genetic diversity.

Question 20

A population is found to have $$p = 0.6$$ and $$q = 0.4. $$What percentage of the population is expected to be homozygous recessive under Hardy-Weinberg equilibrium?

Accepted Answer

$$q^2 = 0.16$ or 16%

Chapter 21: The Evolution of Populations – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard