Question 1

Antelope and kangaroos are both herbivores that feed on grasses and brush. What would you expect to happen if someone set up a game farm and released both species into the same grassy plain?

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Question 2

You suspect that the American alligator is a keystone species in specific habitats in Florida. How could you experimentally prove or disprove this hypothesis?

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Question 3

On the slopes of the Washington Cascades, ecologists have studied some closely related vole species for decades. Many of these vole species, when they occur on separate mountains, tend to choose very similar seed sizes for food. However, when these species occur together on the same mountain slope, their food choices tend to differ, with some species selecting small seeds and others feeding exclusively on larger seeds. This behavior may be an example of
A) resource partitioning.
B) habitat fragmentation.
C) intraspecific range diversion.
D) niche fragmentation.
E) intraspecific competition.

Accepted Answer

Resource partitioning occurs when species divide resources, such as food, to reduce competition, which is what the voles are doing by selecting different seed sizes when they coexist.

Question 4

Two species of buttercup are found in a field in North Dakota, and they tend to flower at approximately the same time in early spring. When some ecology students decided to conduct an experiment in community dynamics, they selectively removed one species from the field by hand-picking all emergent plants. The remaining species showed a significant increase in its population size during the next season. This study demonstrated
A) intraspecific competition.
B) habitat fragmentation.
C) interspecific competition.
D) niche fragmentation.
E) niche realignment.

Accepted Answer

The significant increase in population size of the remaining species after one was removed indicates interspecific competition, where two different species compete for the same resources. Removing one species reduced competition, allowing the other to thrive.

Question 5

How do organisms help to cause the changes that result in their own replacement in succession?

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Question 6

What happens to the soil in an area as succession proceeds?

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Question 7

After forest harvest in an old-growth forest of the Oregon Cascades, an ecologist noted that the species that were present after 5 years differed from the species that were present 25 years later, and these differed from the species that were present 75 years later. What are the general characteristics of the species at each stage, and why does the community change over time?

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Question 8

What distinguishes predators from parasites?)

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Question 9

Fire is increasingly used as a management tool in both forest and grassland ecosystems to increase species diversity. How might fire influence the occurrence of a climax community and species diversity?

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Question 10

Most bacteria can reproduce very quickly, so their populations increase rapidly. Describe the evolutionary process that prevents most human-disease-causing bacterial parasites from causing the human population to become extinct.

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Question 11

Many plants produce chemicals that are used as medicines. For example, the drug digitalis, which stimulates the human heart, is derived from foxglove, a poisonous plant. What advantage does producing toxic compounds have for the plant?

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Question 12

What evidence did Gause and MacArthur find for the competitive exclusion principle?

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Question 13

There are several species of plain-looking, brownish-gray moths that, when they spread their wings, have large bright red or orange eye -shaped circles on their hind wings. What is this adaptation called, and what advantage does it give to the moth?

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Question 14

How might a predator use mimicry to its own advantage?

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Question 15

-The succession shown in the illustration is
A) subclimax.
B) climax.
C) primary.
D) biome.
E) secondary.

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-The succession shown in the illustration is
A)...

Question 16

The caterpillar in the illustration displays 
A) warning coloration.
B) camouflage.
C) startle coloration.
D) aggressive mimicry.
E) chemical defenses.

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The answer of The caterpillar in the illustration displays 
A)...

Question 17

Kudzu is a vine that is native to Japan, but in the United States it is an exotic invader. In many parts of the United States, kudzu is rapidly expanding and outcompeting native species. Explain why kudzu is such an aggressive invader in the United States, but not in its native Japan.

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Question 18

The sea dragon in the illustration displays 
A) warning coloration.
B) camouflage.
C) chemical defenses.
D) aggressive mimicry.
E) startle coloration.

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Question 19

What kinds of plant species are likely to be pioneers in secondary succession? Explain why.

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Question 20

-In the illustration above, the shrubby blueberry and juniper are classified as a community.
A) subclimax
B) primary
C) secondary
D) climax
E) biome

Accepted Answer

Subclimax communities are stable communities that precede the climax stage in ecological succession. They can maintain themselves for a long time under specific environmental conditions, such as those that favor shrubby blueberry and juniper, but they are not the final stage of succession.

Quiz 28: Community Interactions