Chapter 15. 15·9–15·15 Species interactions influence the structure of communities.

Show What You Know - Self Quiz

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You must read each slide, and complete any questions on the slide, in sequence.

Instructions

Check your understanding of concepts from 15·9–15·15 Species interactions influence the structure of communities by answering the following questions.

1.

1. An organism’s role in its environment is called its:

niche.

bio-economy.

keystone interaction.

population.

biomass.

Correct. (See section 15·9 Each species' role in a community is defined as its niche.)

Incorrect. (See section 15·9 Each species' role in a community is defined as its niche.)

2.

2. The “ghost of competition past” refers to the fact that:

interspecies competition constantly occurs in all communities.

competition is difficult to see in nature since it generally leads to competitive exclusion or character displacement and then is not actively occurring (or occurs at a much reduced rate).

competition inevitably leads to extinction of the less efficient competitor.

most competition is a scramble for limited resources rather than a direct head-to-head competition.

All of the above are correct.

Correct. (See section 15·11 Competition can be hard to see, yet it influences community structure.)

Incorrect. (See section 15·11 Competition can be hard to see, yet it influences community structure.)

3.

3. Rabid animals:

froth at the mouth so as to increase the likelihood that the rabies-causing virus is passed on to another host.

must die before their host can be passed on.

have been infected by parasitic bacteria.

often show reduced aggression, which increases their ability to get closer to other animals, thereby spreading the infection.

are infected by a viral ectoparasite.

Correct. (See section 15·13 Parasitism is a form of predation.)

Incorrect. (See section 15·13 Parasitism is a form of predation.)

4.

4. In parts of Africa, colonies of ants live on certain species of acacia trees. The ants feed on leaf structures rich in lipids, while the tree is protected from predation since the ants attack and scare off any predators. The ant and acacia tree relationship is best described by the word or phrase:

character displacement.

coevolution.

competitive exclusion.

realized niche.

resource partitioning.

Correct. (See section 15·10 Interacting species evolve together.)

Incorrect. (See section 15·10 Interacting species evolve together.)

5.

5. Clown fish are protected from predators when they hide among the stinging tentacles of sea anemones. However, some scientists believe that the clown fish may also eat or chase away some predators of the sea anemone. In the first case, the interaction between fish and anemone is ________; in the second case, the interaction is best described as ________.

parasitism, mutualism

commensalism, mutualism

commensalism, parasitism

primary succession, secondary succession

mutualism, commensalism

Correct. (See section 15·14 Not all species interactions are negative: mutualism and commensalism.)

Incorrect. (See section 15·14 Not all species interactions are negative: mutualism and commensalism.)

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