Question 1

Which of the following best describes the process of allopatric speciation?

Accepted Answer

A single population becomes geographically isolated, gene flow stops, and the groups evolve independently until they are genetically incompatible.

Question 2

According to the biological species concept, which of the following is required for two organisms to be considered the same species?

Accepted Answer

They must be able to interbreed and produce fertile offspring.

Question 3

Which of the following is NOT a prezygotic barrier to reproduction?

Accepted Answer

Hybrid sterility

Question 4

A mule is the offspring of a horse and a donkey. Mules are healthy but sterile. Which type of reproductive barrier does this illustrate?

Accepted Answer

Hybrid sterility

Question 5

Why is the biological species concept difficult to apply to asexually reproducing organisms?

Accepted Answer

Asexual organisms do not interbreed, so gene flow cannot be measured.

Question 6

Which scenario best illustrates adaptive radiation?

Accepted Answer

A single ancestral species colonizes an island and evolves into multiple species, each adapted to a different niche.

Question 7

Which of the following is an example of sympatric speciation?

Accepted Answer

A plant species develops polyploidy, resulting in reproductive isolation within the same geographic area.

Question 8

Which of the following equations best represents the total chromosome number in a triploid organism resulting from hybridization?

Accepted Answer

$$2n + n$$

Question 9

In the fruit fly experiment, what type of reproductive barrier was beginning to form between populations raised on different media?

Accepted Answer

Prezygotic behavioral barrier

Question 10

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

Accepted Answer

It cannot be applied to extinct species or asexual organisms.

Question 11

Which reproductive barrier is most likely to occur if two species of frogs breed at different times of the year?

Accepted Answer

Temporal isolation

Question 12

If two populations are geographically isolated and experience different selective pressures, what is the most likely long-term outcome?

Accepted Answer

They will become genetically incompatible and form separate species.

Question 13

Which of the following is an example of postzygotic barrier?

Accepted Answer

Hybrid inviability

Question 14

A population of lizards produces triploid offspring through hybridization. What is the most likely consequence for these triploid lizards?

Accepted Answer

They are sterile but may reproduce asexually.

Question 15

Which of the following best explains why geographic isolation increases the likelihood of speciation?

Accepted Answer

It prevents gene flow, allowing populations to evolve independently.

Question 16

Which of the following is a real-world example of adaptive radiation?

Accepted Answer

Darwin's finches evolving into multiple species on the Galapagos Islands.

Question 17

If a population of plants undergoes polyploidy and becomes reproductively isolated from its parent population, what type of speciation has occurred?

Accepted Answer

Sympatric speciation

Question 18

Which of the following is true about gene flow in the context of speciation?

Accepted Answer

Speciation is most likely when gene flow between populations is completely stopped.

Question 19

Which equation represents the chromosome number in a tetraploid organism formed by the fusion of two diploid gametes?

Accepted Answer

$$2n + 2n$$

Question 20

Which of the following barriers would prevent two closely related insect species from mating due to differences in genitalia structure?

Accepted Answer

Mechanical isolation

Speciation and the Biological Species Concept

Study Guide - Practice Questions