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Biology Now

Anne Houtman; Megan Scudellari; Cindy Malone

Chapter 13

Adaptation and Species - all with Video Answers

Educators


Chapter Questions

03:58

Problem 1

When two populations are reproductively isolated, what else must occur for speciation to happen?
(a) gene flow
(b) genetic divergence
(c) coevolution
(d) convergent evolution
(e) none of the above

Briana De La Torre
Briana De La Torre
Numerade Educator
02:34

Problem 2

2) Traits that are inherited and improve an individual's ability to survive and reproduce are called __________ traits.
(a) adaptive
(b) polymorphic
(c) biological
(d) sympatric
(e) allopatric

Briana De La Torre
Briana De La Torre
Numerade Educator
03:04

Problem 3

Prezygotic isolating mechanisms prevent hybrid of fspring from occurring between species because
(a) the resulting offspring are not fertile and cannot reproduce.
(b) the egg and sperm fuse and form a zygote, but it does not survive.
(c) the egg and sperm do not ever meet or, if they do, cannot fuse to form a zygote.
(d) all of the above

Briana De La Torre
Briana De La Torre
Numerade Educator
01:40

Problem 4

Which of the following reproductive isolating mechanisms prevents mating because the two species are physically unable to mate?
(a) ecological isolation
(b) behavioral isolation
(c) mechanical isolation
(d) gametic isolation
(e) all of the above

Briana De La Torre
Briana De La Torre
Numerade Educator
03:16

Problem 5

Select the correct terms:
Speciation due to geographic separation and (genetic divergence $\bar{J}$ gene flow) of two populations is considered (allopatric / sympatric) speciation.

Briana De La Torre
Briana De La Torre
Numerade Educator
01:29

Problem 6

Select the correct phrases:
(Prezygotic barriers $/$ Postzygotic barriers) are reproductive isolating mechanisms that occur after a zygote has been formed. An example would be (an infertile hybrid $/$ gametes that cannot fuse).

Briana De La Torre
Briana De La Torre
Numerade Educator
01:21

Problem 7

Natural selection
(a) leads to species being better adapted to their environment.
(b) may lead to speciation if there is no gene flow between populations.
(c) may lead to genetic divergence among populations in differing environments.
(d) all of the above
(e) none of the above

Joanna Quigley
Joanna Quigley
Numerade Educator
01:13

Problem 8

Which of the following examples describe an adaptive trait? (Select all that apply.)
(a) A rainforest tree that is vulnerable to storm damage.
(b) A male bird that is more successful than others at attracting a female mate.
(c) A rabbit that is better camouflaged in its environment.
(d) A desert plant that is able to survive drought.
(e) A frog that is more noticeable to predators.

Joanna Quigley
Joanna Quigley
Numerade Educator
01:05

Problem 9

Place the following events in the order in which they are most likely to occur by numbering them from 1 to 5 .
a. Speciation occurs.
b. Genetic divergence takes place.
c. Geographic barrier arises.
d. Gene flow is discontinued.
e. Species adapts to a new environment.

Joanna Quigley
Joanna Quigley
Numerade Educator
01:09

Problem 10

Distinct species that are able to interbreed in nature are said to "hybridize," and their offspring are called "hybrids." The gray oak and the Gambel oak can mate to produce fertile hybrids in regions where they co-occur. However, the gene flow in nature is sufficiently limited that, overall, the two species remain phenotypically distinct. If the hybrid offspring survive well and reproduce to the extent that there is a large population of hybrid individuals that breed between themselves but do not interbreed with either of the two original parent species (the gray and the Gambel), which of the following would you say most likely led to the new hybrid species?
(a) prezygotic reproductive barriers
(b) sympatric speciation
(c) allopatric speciation
(d) postzygotic reproductive barriers
(e) none of the above

Joanna Quigley
Joanna Quigley
Numerade Educator
03:12

Problem 11

11) The four-eyed fish, Anableps anobleps, really has only two eyes, which function as four, enabling the fish to see clearly through both air and water. A. anableps is a surface feeder, so the ability to see above water helps it locate prey such as insects. Its unique eyes also enable it to scan simultaneously for predators attacking from above (such as birds) or below (such as other fish). This species of fish _______ crafted by natural selection.
(a) is an example of coevolution
(b) has an evolutionary adaptation
(c) is an example of sympatric speciation
(d) is an example of allopatric speciation

Briana De La Torre
Briana De La Torre
Numerade Educator
01:01

Problem 12

Give an example of a barrier that might bring about allopatric speciation. In addition to this barrier, what would be necessary for speciation to occur?

Joanna Quigley
Joanna Quigley
Numerade Educator
01:22

Problem 13

Researchers from the Smithsonian Institution were startled to discover that the 3 species of Starksia blennies they had been studying in the Caribbean islands were really 10 different species. How could these researchers have thought that these 10 different reef fish species were only 3 species?

Joanna Quigley
Joanna Quigley
Numerade Educator
01:42

Problem 14

Write Now biology: adaptations Select an organism (other than humans] that you find interesting. Research two adaptations of your organism and describe them in detail. Explain carefully why aach of these features is considered an important adaptation for its species. Discuss how a change in the environment might change the usefulness of these adaptations.

Joanna Quigley
Joanna Quigley
Numerade Educator
01:19

Problem 15

Doing science The eastern and western meadowlarks are very similar in morphology. Both are grassland species with some overlap in their range in the upper Midwest, and each sings a
distinctly different song. Create a hypothesis as to whether these
are two different species or two populations of the same species, and describe an experiment that would enable you to test your hypothesis. What result would support your hypothesis, and what result would cause you to reject your hypothesis?

Joanna Quigley
Joanna Quigley
Numerade Educator
02:03

Problem 16

What do you think? According to the Defenders of Wildlife organization, there were $20-30$ million American range bison in the old West. During the late 1800 s the American range bison were hunted to the brink of extinction, leaving behind a bottleneck population of only 1,091 individuals. The population has since rebounded to about 500,000 bison. Unfortunately, almost all of these bison are the descendants of these few individuals crossbred with domestic cattle by ranchers. Scientists and conservationists want to genetically test bison to find those of pure bison origin to preserve the species. Only these, they argue, should be called American range bison and be allowed to roam free in the national parks as bison. They think hybrids should be confined to farms and ranches, should be called "beefalo" rather than bison, and should not be afforded the protection that pure bison currently have. What do you think? Should bison tainted with cattle genes be removed from free-range parks? Should the government spend scarce conservation monies on genetic testing and breeding efforts to preserve the pure bison population? Investigate conservation efforts and the costs of genetically testing and relocating bison to help you with your decision. Is speciation at the hands of human beings now part of evolution as we know it?

Joanna Quigley
Joanna Quigley
Numerade Educator