Q: In a population of 200 deer mice, 50 are awb/awb, 60 are awb/a+, and 90 are a+/a+. What is the frequency of the awb allele?

$$p(awb) = \frac{2 \times 50 + 60}{2 \times 200} = 0.4$$

Q: A population of plants shows incomplete dominance for flower color: C1C1 = dark violet, C1C2 = lavender, C2C2 = white. If the frequency of the C1 allele is 0.7, what is the expected frequency of lavender flowers under Hardy-Weinberg equilibrium?

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

Question 1

Which of the following best explains why the same Hox gene can cause similar developmental effects in both fruit flies and mice?

Accepted Answer

Hox genes are highly conserved across animals, and their homeobox domains allow them to regulate similar developmental processes in different species.

Question 2

A population of lizards is found to have 36% homozygous dominant (AA), 48% heterozygous (Aa), and 16% homozygous recessive (aa) individuals. According to the Hardy-Weinberg principle, what are the allele frequencies of A and a?

Accepted Answer

$$p = 0.6$$, $$q = 0.4$$

Question 3

Which scenario best illustrates the concept of a genetic bottleneck?

Accepted Answer

A population of cheetahs is reduced to a few dozen individuals due to habitat loss, resulting in loss of genetic diversity.

Question 4

Which of the following is an example of a homeotic mutation?

Accepted Answer

A mutation in Drosophila causes legs to develop where antennae should be.

Question 5

In a population of 200 deer mice, 50 are awb/awb, 60 are awb/a+, and 90 are a+/a+. What is the frequency of the awb allele?

Accepted Answer

$$p(awb) = \frac{2 	imes 50 + 60}{2 	imes 200} = 0.4$$

Question 6

Which evolutionary process is most likely responsible for the high frequency of achromatopsia (color blindness) on Pingelap Atoll?

Accepted Answer

Genetic drift following a population bottleneck, increasing the frequency of a rare allele.

Question 7

Which of the following best describes the difference between homology and homoplasy?

Accepted Answer

Homology is similarity due to shared ancestry, while homoplasy is similarity due to convergent evolution or reversal.

Question 8

A population of plants shows incomplete dominance for flower color: C1C1 = dark violet, C1C2 = lavender, C2C2 = white. If the frequency of the C1 allele is 0.7, what is the expected frequency of lavender flowers under Hardy-Weinberg equilibrium?

Accepted Answer

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

Question 9

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

Accepted Answer

Small population size.

Question 10

Which process is responsible for the initial source of all new alleles in a population?

Accepted Answer

Mutation

Question 11

A researcher observes that a population of finches experiences a drought, resulting in a shift toward deeper beaks in the next generation. Which mode of selection is this an example of?

Accepted Answer

Directional selection

Question 12

Which of the following best explains why inbreeding does NOT cause evolution?

Accepted Answer

Inbreeding changes genotype frequencies but does not change allele frequencies.

Question 13

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

Accepted Answer

The sickle-cell allele is maintained at high frequency in regions with malaria because heterozygotes have higher fitness.

Question 14

Which of the following statements about the molecular clock is correct?

Accepted Answer

It assumes a constant rate of molecular mutation and must be calibrated with fossil or biogeographic data.

Question 15

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

Accepted Answer

Gene flow

Question 16

A new beneficial allele arises in a single individual. Why might this allele still be lost from the population?

Accepted Answer

Genetic drift can eliminate the allele by chance before selection increases its frequency.

Question 17

Which of the following best describes the role of morphogen gradients in embryonic development?

Accepted Answer

They provide positional information to cells, determining spatial organization along body axes.

Question 18

Which of the following is a key difference between allopatric and sympatric speciation?

Accepted Answer

Allopatric speciation requires geographic isolation, while sympatric speciation does not.

Question 19

Which of the following is the correct Hardy-Weinberg equation for genotype frequencies?

Accepted Answer

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

Question 20

Which of the following best describes the effect of purifying selection on genetic variation?

Accepted Answer

It removes deleterious mutations, conserving gene sequences and reducing variation.

Evolution & Phylogenetics Study Guide — Step-by-Step Guidance

Study Guide - Practice Questions

Study Guide - Flashcards