Campbell Biology Concepts & Connections

Martha R. Taylor, Jean L. Dickey, Eric J. Simon, Kelly Hogan, Jane B. Reece

Chapter 14

The Origin of Species - all with Video Answers

Educators

Chapter Questions

Problem 1

Name the two types of speciation represented by this diagram. For each type, describe how reproductive barriers may develop between the new species. (FIGURE CAN'T COPY)

Aren Yarcan

Aren Yarcan

Numerade Educator

Problem 2

Fill in the blanks in the following concept map. (FIGURE CAN'T COPY)

Aren Yarcan

Numerade Educator

Problem 3

Which concept of species would be most useful to a field biologist identifying new plant species in a tropical forest?
a. biological
b. ecological
c. morphological
d. phylogenetic

Aren Yarcan

Numerade Educator

Problem 4

According to the biological species concept, species are defined by their
a. particular roles in a biological community.
b. ability to interbreed and produce viable, fertile offspring.
c. reproductive isolation from nearby populations.
d. common ancestry.

Aren Yarcan

Numerade Educator

Problem 5

Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species that lived side by side in parts of their ranges. However, recent books show them as eastern and western forms of a single species, the yellow-rumped warbler. Most likely, it has been found that these two kinds of warblers
a. live in similar habitats and eat similar foods.
b. interbreed often in nature, and the offspring are viable and fertile.
c. are almost identical in appearance.
d. have many genes in common.

Aren Yarcan

Numerade Educator

Problem 6

Which of the following is an example of a postzygotic reproductive barrier?
a. One Ceanothus shrub lives on acid soil, another on alkaline soil.
b. Mallard and pintail ducks mate at different times of year.
c. Two species of leopard frogs have different mating calls.
d. Hybrid offspring of two species of jimsonweeds always die before reproducing.

Aren Yarcan

Numerade Educator

Problem 7

Biologists have found more than 500 species of fruit flies on the various Hawaiian Islands, all apparently descended from a single ancestor species. This example illustrates
a. polyploidy.
b. temporal isolation.
c. adaptive radiation.
d. sympatric speciation.

Aren Yarcan

Numerade Educator

Problem 8

A new plant species $\mathrm{C}$, which formed from hybridization of species $\mathrm{A}(2 n=16)$ with species $\mathrm{B}(2 n=12),$ would probably produce gametes with a chromosome number of
a. 12.
b. 14.
c. 16.
d. 28.

Aren Yarcan

Numerade Educator

Problem 9

A horse $(2 n=64)$ and a donkey $(2 n=62)$ can mate and produce a mule. How many chromosomes would there be in a mule's body cells?
a. 31
b. 62
c. 63
d. 126

Aren Yarcan

Numerade Educator

Problem 10

What prevents horses and donkeys from hybridizing to form a new species?
a. limited hybrid fertility
b. limited hybrid viability
c. hybrid breakdown
d. gametic isolation

Aren Yarcan

Numerade Educator

Problem 11

When hybrids produced in a hybrid zone can breed with each other and with both parent species, and they survive and reproduce as well as members of the parent species, one would predict that
a. the hybrid zone would be stable.
b. sympatric speciation would occur.
c. reinforcement of reproductive barriers would keep the parent species separate.
d. reproductive barriers would lessen and the two parent species would fuse.

Aren Yarcan

Numerade Educator

Problem 12

Which of the following factors would not contribute to allopatric speciation?
a. A population becomes geographically isolated from the parent population.
b. The separated population is small, and genetic drift occurs.
c. The isolated population is exposed to different selection pressures than the parent population.
d. Gene flow between the two populations continues to occur.

Aren Yarcan

Numerade Educator

Problem 13

Explain how each of the following makes it difficult to clearly define a species: variation within a species, geographically isolated populations, asexual species, fossil organisms.

Aren Yarcan

Numerade Educator

Problem 14

Explain why allopatric speciation would be less likely on an island close to a mainland than on a more isolated island.

Aren Yarcan

Numerade Educator

Problem 15

What does the term punctuated equilibria describe?

Aren Yarcan

Numerade Educator

Problem 16

Can factors that cause sympatric speciation also cause allopatric speciation? Explain.

Aren Yarcan

Numerade Educator

Problem 17

Cultivated American cotton plants have a total of 52 chromosomes $(2 n=52) .$ In each cell, there are 13 pairs of large chromosomes and 13 pairs of smaller chromosomes. Old World cotton plants have 26 chromosomes $(2 n=26),$ all large. Wild American cotton plants have 26 chromosomes, all small. Propose a testable hypothesis to explain how cultivated American cotton probably originated.

Noah Boudrie

Numerade Educator

Problem 18

Explain how the murky waters of Lake Victoria may be contributing to the decline in cichlid species. How might these polluted waters affect the formation of new species?

Caroline Jones

Numerade Educator

Problem 19

The red wolf, Canis rufus, which was once widespread in the southeastern and south central United States, was declared extinct in the wild by $1980 .$ Saved by a captive breeding program, the red wolf has been reintroduced in areas of eastern North Carolina. The current wild population is estimated to be about 100 individuals. It is presently being threatened with extinction due to hybridization with coyotes, Canis latrans, which have become more numerous in the area. Red wolves and coyotes differ in terms of morphology, DNA, and behavior, although these differences may disappear if interbreeding continues. Although the red wolf has been designated as an endangered species under the Endangered Species Act, some people think that its endangered status should be withdrawn and resources should not be spent to protect what is not a "pure" species. Do you agree? Why or why not?

Caroline Jones

Numerade Educator