Q: A population of beetles has two alleles for color: B (black) and b (brown). If the frequency of B is 0.7 and b is 0.3, what is the expected frequency of heterozygotes under Hardy-Weinberg equilibrium?

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

Question 1

Which of the following best describes Darwin's theory of evolution by natural selection?

Accepted Answer

Species evolve over time as individuals with advantageous traits survive and reproduce more successfully.

Question 2

Which evidence most strongly supports the theory of evolution by natural selection?

Accepted Answer

The existence of homologous structures and vestigial organs across different species.

Question 3

Which equation is used to calculate allele frequencies in a population under Hardy-Weinberg equilibrium?

Accepted Answer

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

Question 4

A population of beetles has two alleles for color: B (black) and b (brown). If the frequency of B is 0.7 and b is 0.3, what is the expected frequency of heterozygotes under Hardy-Weinberg equilibrium?

Accepted Answer

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

Question 5

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

Accepted Answer

Natural selection is present.

Question 6

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

Accepted Answer

Genetic drift

Question 7

Which of the following is an example of a prezygotic reproductive barrier?

Accepted Answer

Temporal isolation

Question 8

Which statement best explains the concept of adaptive radiation?

Accepted Answer

The rapid evolution of many diverse species from a common ancestor when new habitats become available.

Question 9

Which of the following best describes allopatric speciation?

Accepted Answer

Speciation occurs when populations are separated by a physical barrier.

Question 10

Which scientist's experiments demonstrated that organic molecules could form under early Earth conditions?

Accepted Answer

Stanley Miller

Question 11

Which of the following is a postzygotic barrier to reproduction?

Accepted Answer

Hybrid sterility

Question 12

Which of the following best describes the founder effect?

Accepted Answer

A small group of individuals establishes a new population, leading to reduced genetic diversity.

Question 13

Which of the following is an example of homologous structures?

Accepted Answer

The flippers of a whale and the arms of a human.

Question 14

Which process can introduce new alleles into a population?

Accepted Answer

Mutation

Question 15

Which of the following best explains why vestigial structures are important evidence for evolution?

Accepted Answer

They indicate that some structures have lost their original function over time.

Question 16

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

Accepted Answer

A population of birds migrates and breeds with a neighboring population, introducing new alleles.

Question 17

Which of the following statements about microevolution is correct?

Accepted Answer

Microevolution involves changes in allele frequencies within a population over time.

Question 18

Which of the following is a direct result of genetic drift in a small population?

Accepted Answer

Random changes in allele frequencies

Question 19

Which of the following best describes the biological species concept?

Accepted Answer

Species are groups of organisms that can interbreed and produce fertile offspring.

Question 20

Which of the following is an example of disruptive selection?

Accepted Answer

A population of fish where both very small and very large individuals are favored over medium-sized ones.

Study Guide: Evolution, Population Genetics, and the History of Life (Chapters 22–25)

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