Q: A population of 1,000 individuals has two alleles for a gene: A and a. If the frequency of allele A ($$p) is 0.7 $$and the frequency of allele a ($$q) is 0.3$$, what is the expected frequency of heterozygotes ($$2pq) $$under Hardy–Weinberg equilibrium?

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

Question 1

Which of the following best describes the difference between Lamarckian evolution and Darwinian evolution?

Accepted Answer

Lamarckian evolution proposes that acquired characteristics can be inherited, while Darwinian evolution relies on variation and natural selection acting on heritable traits.

Question 2

Which of the following is an example of artificial selection?

Accepted Answer

Breeding dogs to enhance specific traits such as size or coat color.

Question 3

A population of 1,000 individuals has two alleles for a gene: A and a. If the frequency of allele A ($$p) is 0.7 $$and the frequency of allele a ($$q) is 0.3$$, what is the expected frequency of heterozygotes ($$2pq) $$under Hardy–Weinberg equilibrium?

Accepted Answer

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

Question 4

Which of the following is NOT an assumption of the Hardy–Weinberg principle?

Accepted Answer

Natural selection is acting on the population.

Question 5

A population of frogs is split by the construction of a highway, preventing individuals from crossing. Over time, the two groups diverge genetically. This is an example of:

Accepted Answer

Allopatric speciation by vicariance.

Question 6

Which of the following best explains why natural selection does NOT lead to perfection?

Accepted Answer

Environments change and genetic variation is limited, so populations can only adapt to current conditions.

Question 7

Which of the following is a postzygotic reproductive isolating mechanism?

Accepted Answer

Hybrid offspring of two species are sterile.

Question 8

In a population of 500 plants, a mutation occurs that increases drought resistance. Over several generations, the frequency of the mutant allele increases. Which of Darwin's postulates does this scenario best illustrate?

Accepted Answer

Variation in traits leads to differential survival and reproduction.

Question 9

Which of the following statements about genetic drift is correct?

Accepted Answer

Genetic drift can decrease genetic variation in small populations due to random sampling error.

Question 10

A researcher observes that two populations of birds that were once separated by a mountain range come into contact again. The populations interbreed and produce viable, fertile offspring. What is the most likely outcome?

Accepted Answer

Fusion of the two populations into a single species.

Question 11

Which of the following best describes the biological species concept?

Accepted Answer

Species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

Question 12

Which process is most likely to increase genetic variation in a population?

Accepted Answer

Mutation introducing new alleles.

Question 13

A population of insects is exposed to a new pesticide. After several generations, most individuals are resistant. Which of the following best explains this outcome?

Accepted Answer

Individuals with resistance alleles survived and reproduced more, increasing the frequency of resistance in the population.

Question 14

Which of the following is an example of disruptive selection?

Accepted Answer

In a population of birds, individuals with either very short or very long beaks have higher fitness than those with intermediate beak lengths.

Question 15

Which of the following scenarios best illustrates the founder effect?

Accepted Answer

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

Question 16

Which of the following is a key difference between gene flow and genetic drift?

Accepted Answer

Gene flow involves the movement of alleles between populations, while genetic drift is random change in allele frequencies within a population.

Question 17

Which of the following is an example of prezygotic reproductive isolation?

Accepted Answer

Two species of frogs breed in different habitats and never encounter each other.

Question 18

A botanist discovers a new plant species that arose when a chromosome duplication event led to a new polyploid individual that could not mate with the parent population. This is an example of:

Accepted Answer

Sympatric speciation by polyploidization.

Question 19

Which of the following best explains why inbreeding increases the frequency of homozygotes in a population?

Accepted Answer

Inbreeding increases the probability that two alleles at a locus are identical by descent.

Question 20

Which of the following is a real-world example of balancing selection?

Accepted Answer

The persistence of the sickle-cell allele in human populations where malaria is present.

Evolutionary Processes and Speciation: Study Guide for Chapters 22–24

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드