Question 1

Which of the following best describes allopatric speciation?

Accepted Answer

Speciation that occurs when populations are separated by a physical barrier, leading to genetic divergence.

Question 2

According to the biological species concept, which of the following is the primary criterion for defining a species?

Accepted Answer

Ability to interbreed and produce viable, fertile offspring.

Question 3

A population of birds is separated by the formation of a new river, preventing gene flow between the two groups. Over time, the two populations diverge genetically. This is an example of:

Accepted Answer

Vicariance leading to allopatric speciation.

Question 4

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

Accepted Answer

It cannot distinguish between cryptic species that look similar but are genetically distinct.

Question 5

In a hybrid zone, what is the most likely outcome if hybrids have lower fitness than either parent species?

Accepted Answer

Reinforcement, leading to increased reproductive isolation.

Question 6

Which of the following scenarios best illustrates sympatric speciation?

Accepted Answer

A population of insects evolves to specialize on different host plants within the same geographic area, leading to reproductive isolation.

Question 7

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

Accepted Answer

Two species of frogs breed in different seasons, preventing mating.

Question 8

A botanist discovers a new plant species that arose when an error in meiosis caused chromosome doubling, resulting in a tetraploid individual. This is an example of:

Accepted Answer

Polyploid speciation.

Question 9

Which of the following best explains why the phylogenetic species concept is useful for identifying cryptic species?

Accepted Answer

It uses genetic data to identify monophyletic groups, even when morphological differences are absent.

Question 10

If two populations come into secondary contact and hybrids have equal fitness to parent species, what is the most likely long-term outcome?

Accepted Answer

Fusion of the two populations into a single species.

Question 11

Which of the following equations best represents the relationship between gene flow ($$m$$), genetic drift ($$s$$), and divergence in allopatric populations?

Accepted Answer

$$D = s - m$$

Question 12

A researcher observes that two populations of beetles living in the same forest feed on different types of leaves and rarely interbreed. Which concept best explains their speciation?

Accepted Answer

Ecological speciation via sympatry.

Question 13

Which of the following is NOT a postzygotic barrier?

Accepted Answer

Temporal isolation.

Question 14

Which of the following is a real-world example of vicariance?

Accepted Answer

The formation of the Isthmus of Panama separating marine organisms into Atlantic and Pacific populations.

Question 15

Which of the following best describes reinforcement in the context of speciation?

Accepted Answer

Natural selection increases reproductive isolation between populations when hybrids have low fitness.

Question 16

Which of the following is a key advantage of the phylogenetic species concept over the biological species concept?

Accepted Answer

It can be applied to both sexual and asexual organisms.

Question 17

A hybrid zone is most likely to persist when:

Accepted Answer

Hybrids have intermediate fitness compared to parent species.

Question 18

Which of the following is an example of dispersal leading to allopatric speciation?

Accepted Answer

A few individuals from a mainland bird population colonize a distant island and evolve into a new species.

Question 19

Which of the following best explains why polyploidy is a common mechanism of speciation in plants but rare in animals?

Accepted Answer

Plants can often self-fertilize and tolerate changes in chromosome number, while animals usually cannot.

Speciation (Ch. 24): Mechanisms and Concepts

Study Guide - Practice Questions

Study Guide - Flashcards