Question 1

Which of the following best describes the role of mutations in evolution?

Accepted Answer

Mutations are the raw material for evolution, as they introduce genetic variation that can lead to new phenotypes.

Question 2

A population of insects is separated by a newly formed river, and over thousands of years, the two groups accumulate genetic differences and can no longer interbreed. What type of speciation has occurred?

Accepted Answer

Allopatric speciation

Question 3

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

Accepted Answer

Two species of frogs breed at different times of the year.

Question 4

Why can't the biological species concept be applied to fossil organisms?

Accepted Answer

Fossil organisms cannot be observed for reproductive behavior.

Question 5

Which process can result in the rapid formation of a new plant species due to a change in chromosome number?

Accepted Answer

Polyploidy

Question 6

A population of birds lives in a continuous forest, but some individuals begin to specialize in eating seeds from a new plant species. Over time, these birds mate only with others that eat the same seeds, leading to genetic divergence. What type of speciation is this?

Accepted Answer

Sympatric speciation

Question 7

Which of the following best explains why 'reptiles' is considered a paraphyletic group?

Accepted Answer

It excludes some descendants, such as birds, from the group.

Question 8

According to the impact theory, what was the primary cause of the mass extinction at the end of the Cretaceous period?

Accepted Answer

A meteorite or comet impact that dramatically changed the environment

Question 9

Which of the following statements about gradualism and punctuated equilibrium is correct?

Accepted Answer

Gradualism suggests small, incremental changes over time, while punctuated equilibrium suggests long periods of little change interrupted by rapid speciation.

Question 10

Which of the following is a postzygotic reproductive barrier?

Accepted Answer

Hybrid offspring between two plant species fail to survive to maturity.

Question 11

A phylogenetic tree constructed using DNA sequence data is an example of which approach?

Accepted Answer

Cladistics

Question 12

Which of the following best defines a clade?

Accepted Answer

A group of organisms consisting of a common ancestor and all its descendants.

Question 13

Which of the following is an example of adaptive radiation?

Accepted Answer

A single species of finch evolves into multiple species, each adapted to a different food source on the Galápagos Islands.

Question 14

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

Accepted Answer

Snapping shrimp populations separated by the Isthmus of Panama and unable to interbreed.

Question 15

Which of the following best describes a monophyletic group?

Accepted Answer

A group that includes a common ancestor and all of its descendants.

Question 16

Which of the following is a polyphyletic group?

Accepted Answer

A group that excludes the most recent common ancestor of its members.

Question 17

Which of the following is a derived characteristic?

Accepted Answer

A trait that evolved in the most recent common ancestor of a group and is unique to that group.

Question 18

Which of the following human activities is NOT a major contributor to the current (sixth) mass extinction?

Accepted Answer

Gradual plate tectonic movement

Question 19

If two populations of the same species are separated by a mountain range and accumulate genetic differences over time, which equation best represents the decrease in gene flow ($$G) $$between the populations as a function of time ($$t$$)?

Accepted Answer

$$G = G_0$ e$$^{-kt}$$

Question 20

Which of the following best explains why DNA analysis is useful for defining species, especially in bacteria and archaea?

Accepted Answer

DNA analysis can reveal if two organisms are more than 97% identical, indicating they are the same species.

Chapter 14: Speciation and Extinction – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards