CLEP Biology Mechanisms of Natural Selection 5

Question 1

Co-evolution between a flower and its specific pollinator is driven by:

Accepted Answer

Reciprocal selection pressures between two interacting species

Answer

Co-evolution involves reciprocal evolutionary changes in two or more species that interact closely, each acting as a selection pressure on the other.

Question 2

Antibiotic resistance in bacteria evolving within a single patient's infection is an example of:

Accepted Answer

Directional selection acting on existing variation

Answer

Antibiotic treatment acts as directional selection, favoring pre-existing resistant bacteria over sensitive ones already present in the population.

Question 3

Which type of reproductive isolation involves hybrid offspring that are sterile?

Accepted Answer

Hybrid sterility

Answer

Hybrid sterility is a postzygotic barrier where hybrids survive but cannot reproduce, as seen in mules (horse × donkey crosses).

Question 4

The concept of punctuated equilibrium proposes that evolution:

Accepted Answer

Occurs in bursts of rapid change followed by long periods of stasis

Answer

Punctuated equilibrium, proposed by Gould and Eldredge, suggests species remain relatively unchanged for long periods interrupted by rapid evolutionary change.

Question 5

Frequency-dependent selection occurs when:

Accepted Answer

The fitness of a phenotype depends on how common it is in the population

Answer

In frequency-dependent selection, a phenotype's fitness increases when rare (negative frequency-dependence) or when common (positive frequency-dependence).

CLEP Practice Test

CLEP Practice Test

CLEP Biology Mechanisms of Natural Selection 5