Question 1

Which of the following best describes the biological species concept?

Accepted Answer

A population whose members can interbreed and produce viable, fertile offspring.

Question 2

Which of the following is an example of a prezygotic reproductive barrier?

Accepted Answer

Temporal isolation

Question 3

Two species of frogs breed in the same pond, but one breeds in early spring and the other in late summer. What type of reproductive barrier is this?

Accepted Answer

Temporal isolation

Question 4

Which of the following scenarios best illustrates allopatric speciation?

Accepted Answer

A river divides a population of rodents, leading to genetic divergence over time.

Question 5

Which of the following is a postzygotic barrier?

Accepted Answer

Reduced hybrid viability

Question 6

A mule is the offspring of a horse and a donkey. Mules are generally sterile. This is an example of which type of reproductive barrier?

Accepted Answer

Reduced hybrid fertility

Question 7

Which of the following equations correctly represents the doubling of chromosome number in allopolyploid speciation?

Accepted Answer

$$n_1$$ + $$n_2 = 2n$ (hybrid zygote),2n$ doubled to 4n$ (allopolyploid)

Question 8

Which of the following is a limitation of the biological species concept?

Accepted Answer

It cannot be applied to fossils.

Question 9

In a population of fish, some individuals develop a body shape that allows rapid bursts of speed, while others develop a shape for steady swimming. If predators are present, which body shape is favored and why?

Accepted Answer

Rapid burst shape, because it increases escape acceleration from predators.

Question 10

Which of the following best explains why two different species of birds may look similar but are not the same species?

Accepted Answer

They share a recent common ancestor but are reproductively isolated.

Question 11

Which of the following is an example of sympatric speciation?

Accepted Answer

A plant undergoes polyploidy, resulting in a new species within the same area.

Question 12

Which of the following is NOT a prezygotic barrier?

Accepted Answer

Reduced hybrid viability

Question 13

A population of fruit flies is split into two groups, one raised on starch medium and the other on maltose medium. After 40 generations, flies prefer to mate with those raised on the same medium. What does this experiment demonstrate?

Accepted Answer

Habitat isolation due to environmental preference.

Question 14

Which of the following best describes hybrid breakdown?

Accepted Answer

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

Question 15

Which of the following is an example of behavioral isolation?

Accepted Answer

Two species of crickets have different mating calls.

Question 16

Which equation represents the chromosome number in an autotetraploid formed from a diploid cell with $$2n = 6$$?

Accepted Answer

$$2n = 6 \rightarrow 4n = 12$$

Question 17

Which of the following is a real-world example of allopatric speciation?

Accepted Answer

Formation of new shrimp species on either side of the Isthmus of Panama.

Question 18

Which of the following best explains why the biological species concept cannot be applied to fossils?

Accepted Answer

Fossils do not provide information about reproductive isolation.

Question 19

Which of the following is an example of gametic isolation?

Accepted Answer

Sperm of one species cannot fertilize eggs of another species.

Question 20

Which of the following best describes the process of speciation?

Accepted Answer

The formation of new species from pre-existing species due to genetic isolation.

Speciation: Mechanisms and Concepts in Evolutionary Biology

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