Question 1

Which of the following best describes the Central Dogma of Molecular Biology?

Accepted Answer

Information flows from DNA to RNA to proteins.

Question 2

A population of birds experiences a drought that favors individuals with larger beaks, resulting in a shift in the average beak size over several generations. Which type of selection is this an example of?

Accepted Answer

Directional selection

Question 3

Which of the following statements about genetic drift is correct?

Accepted Answer

It is a change in allele frequencies due to chance events.

Question 4

In a population of cheetahs that has experienced a severe reduction in numbers due to a natural disaster, which evolutionary mechanism is most likely to have a strong effect on allele frequencies?

Accepted Answer

Genetic drift (bottleneck effect)

Question 5

Which of the following scenarios best illustrates gene flow?

Accepted Answer

Individuals from one population migrate and breed with individuals from another population, mixing their alleles.

Question 6

Which of the following is NOT a possible outcome of stabilizing selection?

Accepted Answer

Increased frequency of extreme phenotypes

Question 7

A population of black-bellied seed crackers has individuals with either very short or very long beaks surviving, while those with intermediate beak lengths do not. What type of selection is this?

Accepted Answer

Disruptive selection

Question 8

Which of the following best defines a gene?

Accepted Answer

A sequence of DNA that codes for an individual protein

Question 9

In the context of sexual selection, which of the following is an example of female choice?

Accepted Answer

Female zebra finches preferring to mate with males that have brighter coloration

Question 10

Which of the following equations represents the Hardy-Weinberg equilibrium for a gene with two alleles, $$A$$ and $$a$$, with frequencies $$p$$ and $$q$$?

Accepted Answer

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

Question 11

Which of the following is a direct result of mutation in a population?

Accepted Answer

Introduction of new alleles

Question 12

A rare allele in a population increases in frequency because individuals with that allele have higher fitness in a changing environment. This is an example of:

Accepted Answer

Balancing selection (frequency-dependent selection)

Question 13

Which of the following best explains why females usually invest more in their offspring than males do?

Accepted Answer

Females typically produce fewer, larger gametes (eggs) that require more resources.

Question 14

Which evolutionary mechanism is most likely to decrease the average fitness of a population due to random loss of alleles?

Accepted Answer

Genetic drift

Question 15

Which of the following is an example of sexual dimorphism?

Accepted Answer

Male scarlet tanagers are bright red while females are duller in color.

Question 16

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

Accepted Answer

Balancing selection

Question 17

A population of beetles is split by a river, and over time, the two groups develop different allele frequencies. Later, some beetles cross the river and breed with the other group. What evolutionary mechanism is occurring when the beetles cross and breed?

Accepted Answer

Gene flow

Question 18

Which of the following is a correct statement about the effect of mutation on a population?

Accepted Answer

Mutation introduces new alleles, increasing genetic variation.

Question 19

In a population, the genotype frequencies for a gene with two alleles $$A$$ and $$a$$ are $$AA = 0.36$$, $$Aa = 0.48$$, and $$aa = 0.16. $$What are the allele frequencies of $$A$$ and $$a$$?

Accepted Answer

$$A = 0.6$$, $$a = 0.4$$

Question 20

Which of the following is an example of heterozygote advantage?

Accepted Answer

Individuals with one sickle cell allele and one normal allele are more resistant to malaria than either homozygote.

Lecture 2: Evolutionary Processes

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