Question 1

Which of the following best describes phenotypic plasticity?

Accepted Answer

The ability of an individual to change in response to its environment, without a genetic component, within its lifetime.

Question 2

A population of beetles is reduced from 1,000 to 10 individuals due to a flood. The surviving beetles have a different allele frequency than the original population. This is an example of:

Accepted Answer

Bottleneck effect

Question 3

Which of the following statements about genetic drift is TRUE?

Accepted Answer

Genetic drift can lead to the loss or fixation of alleles purely by chance, especially in small populations.

Question 4

Which of the following processes is considered non-random?

Accepted Answer

Natural selection

Question 5

A gene pool is best defined as:

Accepted Answer

All copies of all alleles at every locus in all members of a population.

Question 6

Which of the following is an example of gene flow?

Accepted Answer

Individuals from one population of deer migrate and breed with another population, introducing new alleles.

Question 7

If a population of 100 marbles contains 60 green marbles and 40 brown marbles, what is the frequency of the brown allele if each marble represents a single allele?

Accepted Answer

$$f_{brown} = \frac{40}{100} = 0.4$$

Question 8

Which of the following scenarios best illustrates the founder effect?

Accepted Answer

A few individuals from a mainland bird population colonize a new island, and their descendants have different allele frequencies than the original population.

Question 9

Which of the following is NOT a mechanism of microevolution?

Accepted Answer

Speciation

Question 10

A population of fish in a lake is isolated from other lakes. Over time, a few fish from a neighboring lake enter and breed with the isolated population. What is the most likely genetic consequence?

Accepted Answer

The two populations will become more genetically similar due to gene flow.

Question 11

Which of the following best describes a genome?

Accepted Answer

The complete set of all genetic material of an organism.

Question 12

If an individual is homozygous for a gene, which of the following is true?

Accepted Answer

The individual has two identical alleles for that gene.

Question 13

Which of the following is a correct statement about natural selection?

Accepted Answer

Natural selection is a non-random process where individuals with higher fitness are more likely to survive and reproduce.

Question 14

A population of rabbits has the following genotype frequencies for a gene: $$AA = 0.36$$, $$Aa = 0.48$$, $$aa = 0.16. $$What is the frequency of the $$A$$ allele?

Accepted Answer

$$f_A = 0.36 + 0.24 = 0.60$$

Question 15

Which of the following is an example of phenotypic plasticity in a real-world context?

Accepted Answer

A plant changes its leaf shape in response to sunlight exposure during its lifetime.

Question 16

Which of the following best explains why genetic drift can lead to the fixation of alleles in small populations?

Accepted Answer

Random sampling error has a larger effect in small populations, so alleles can become fixed or lost by chance.

Question 17

Which of the following is NOT a result of gene flow?

Accepted Answer

Increased genetic isolation of populations.

Question 18

A population of lizards is split by a new river, and over time, the two groups develop different allele frequencies. Which mechanism of microevolution is most likely responsible for the initial divergence?

Accepted Answer

Genetic drift

Question 19

Which of the following is a correct definition of an allele?

Accepted Answer

A variant form of a gene found at a specific locus.

Question 20

Which of the following equations correctly represents the calculation of allele frequency for allele $$A in a $$population with $$n_{AA}$$ individuals with genotype $$AA$$, $$n_{Aa}$$ with $$Aa$$, and $$n_{aa}$$ with $$aa$$, and total number of individuals $$N$$?

Accepted Answer

$$f_A = \frac{2n_{AA} + n_{Aa}}{2N}$$

Microevolution and Genetic Variation: Study Notes for General Biology

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