Question 1

Which of the following best describes the Biological Species Concept as defined by Ernst Mayr?

Accepted Answer

Species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

Question 2

Which of the following is an example of a prezygotic isolating mechanism?

Accepted Answer

Temporal isolation

Question 3

A population of frogs is separated by a newly formed river, preventing them from mating. Over time, the two populations evolve distinct mating calls. What type of speciation is most likely occurring?

Accepted Answer

Allopatric speciation

Question 4

Which reproductive isolating mechanism is illustrated when two species of plants flower at different times of the year, preventing cross-pollination?

Accepted Answer

Temporal isolation

Question 5

In a population of fish, some individuals develop a preference for breeding in rocky areas while others prefer sandy areas, even though both habitats are in the same lake. What type of isolation is this?

Accepted Answer

Habitat isolation

Question 6

Which of the following is a postzygotic barrier to reproduction?

Accepted Answer

Reduced hybrid viability

Question 7

A mule is the offspring of a horse and a donkey, but mules are sterile. Which reproductive isolating mechanism does this illustrate?

Accepted Answer

Reduced hybrid fertility

Question 8

Which process is most likely to result in sympatric speciation in plants?

Accepted Answer

Polyploidy

Question 9

Character displacement is most likely to occur under which condition?

Accepted Answer

Two species occupy the same habitat and compete for the same resources.

Question 10

Which equation best represents the concept of gene flow between populations?

Accepted Answer

$$p' = (1 - m)p + m p_m$$

Question 11

If two populations of birds develop different songs that attract only their own kind, which isolating mechanism is at work?

Accepted Answer

Behavioral isolation

Question 12

Which of the following statements about allopatric and sympatric speciation is correct?

Accepted Answer

Allopatric speciation involves geographic isolation, while sympatric speciation occurs in the same location.

Question 13

Which scenario best illustrates gametic isolation?

Accepted Answer

Two species of sea urchins release gametes into the water, but sperm from one species cannot fertilize eggs of the other.

Question 14

Which of the following is NOT a limitation of the Biological Species Concept?

Accepted Answer

It easily distinguishes species based on physical appearance alone.

Question 15

A population of insects splits into two groups, one feeding on apples and the other on hawthorns, in the same geographic area. Over generations, they stop interbreeding. What type of speciation is this?

Accepted Answer

Sympatric speciation

Question 16

Which of the following best explains why gene flow can prevent speciation?

Accepted Answer

Gene flow homogenizes genetic differences, making populations more similar.

Question 17

Which of the following is most likely to occur if two closely related species come into contact and hybridize, but the hybrids have reduced viability?

Accepted Answer

Reproductive isolation will be reinforced.

Question 18

Which of the following is a real-world example of mechanical isolation?

Accepted Answer

Two species of snails have shells that spiral in opposite directions, preventing mating.

Question 19

Which of the following best describes hybrid breakdown?

Accepted Answer

Hybrids are viable and fertile, but their offspring are weak or sterile.

Question 20

Which of the following equations represents the Hardy-Weinberg equilibrium, which is disrupted during speciation?

Accepted Answer

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

Speciation and the Biological Species Concept

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