Q: A population of 1000 plants has two alleles for flower color: R and r. If the frequency of allele R ($$p) is 0.7 $$and allele r ($$q) is 0.3$$, 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 'descent with modification' as it relates to evolutionary biology?

Accepted Answer

Species accumulate differences from their ancestors as they adapt to different environments over time.

Question 2

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

Accepted Answer

Small population size

Question 3

A population of 1000 plants has two alleles for flower color: R and r. If the frequency of allele R ($$p) is 0.7 $$and allele r ($$q) is 0.3$$, 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 scenario best illustrates the founder effect in genetic drift?

Accepted Answer

A small group of individuals colonizes a new island, and their descendants show different allele frequencies than the original population.

Question 5

Which of the following is a direct consequence of genetic drift in small populations?

Accepted Answer

Allele frequencies can change at random, sometimes leading to fixation of harmful alleles

Question 6

In a population of 500 birds, the allele frequency for allele A ($$p) is 0.6 $$and for allele a ($$q) is 0.4. $$What is the expected frequency of genotype AA under Hardy-Weinberg equilibrium?

Accepted Answer

$$p^2$$ = $$0.6^2 = 0.36$

Question 7

Which of the following best explains why antibiotic resistance in bacteria is an example of natural selection?

Accepted Answer

Resistant bacteria survive and reproduce in the presence of antibiotics, increasing the frequency of resistance alleles.

Question 8

A population of finches on an island has three beak types: cactus-eater, insect-eater, and seed-eater. What evolutionary process most likely led to these differences?

Accepted Answer

Natural selection favoring beak shapes adapted to specific diets

Question 9

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

Accepted Answer

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

Question 10

If a population is in Hardy-Weinberg equilibrium, what will happen to allele frequencies from one generation to the next?

Accepted Answer

Allele frequencies will remain constant.

Question 11

Which of the following is an example of adaptation?

Accepted Answer

A population of insects develops resistance to a pesticide over several generations.

Question 12

Which process can introduce new alleles into a population, potentially increasing genetic variation?

Accepted Answer

Gene flow

Question 13

A population of prairie chickens experienced a bottleneck event, reducing its size drastically. What is a likely genetic consequence?

Accepted Answer

Loss of genetic variation and possible fixation of harmful alleles

Question 14

Which of the following statements about evolutionary fitness is correct?

Accepted Answer

Fitness is measured by the ability to survive and reproduce in a given environment.

Question 15

Which of the following would violate Hardy-Weinberg equilibrium in a population?

Accepted Answer

Natural selection favoring a specific genotype

Question 16

A population of 2000 bacteria is exposed to an antibiotic. After treatment, only 100 survive, all of which are resistant. What evolutionary process has occurred?

Accepted Answer

Natural selection

Question 17

Which of the following is a real-world example of genetic drift?

Accepted Answer

A rare allele becomes common in a small population after a few individuals survive a disaster.

Question 18

If $$p = 0.8$$ and $$q = 0.2 in a $$population, what is the expected frequency of the homozygous recessive genotype under Hardy-Weinberg equilibrium?

Accepted Answer

$$q^2$$ = $$0.2^2 = 0.04$

Question 19

Which of the following mechanisms can decrease genetic variation within a population?

Accepted Answer

Genetic drift

Question 20

Which statement best describes the role of mutation in evolution?

Accepted Answer

Mutation introduces new genetic variation, which can be acted upon by natural selection.

Evolution of Populations: Mechanisms, Adaptation, and Genetic Equilibrium

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