托福阅读真题+题目+答案：Species Competition

托福阅读真题+题目+答案：Species Competition

P1 Interspecific competition occurs when two or more species seek the same limited resource. In the 1930s, Russian biologist G. F. Gause devised a set of elegant laboratory experiments that provide the basis for our formal understanding of competition. Gause grew two different species of the single-celled Paramecium—P.aurelia and P. caudatum - -separately and together. Populations of both species always increased more rapidly when they were grown alone. When grown together, populations of both species grew more slowly.█Eventually, P. aurelia totally displaced P. caudatum . █The results of his experiments with Paramecium species, along with similar experiments he performed on other organisms, led Gause to form this postulate: two species that directly compete for essential resources cannot coexist; one species will eventually displace the other.█This postulate has come to be known as the competitive exclusion principle.█

1.According to paragraph 1, which of the following statements about Gauss's experiments with Paramecium is true?

A They were all conducted using various Paramecium species together

B They were all performed in a laboratory setting

C They were designed to test the already accepted principle of competitive exclusion

D They proved that species that grow slowly will not displace each other

P2 An acre of tropical forest may include over 100 species of trees, all of which depend on the same soil, water, and nutrients. Freshwater lakes may have dozens of species of fish, all of which feed on the planktonic algae and animals suspended in the water. Indeed, two or more species of Paramecium may be found in the same lake. These and many other examples from ecological communities in nature seem to contradict Gause's principle. If two competing species cannot coexist in the laboratory, how are they able to coexist in natural settings? This question has been the basis for hundreds of ecological studies.

2.The author notes that numerous species of trees all "depend on the same soil" and multiple species offish all "feed on the planktonic algae and animals suspended in the wafer" in lakes in order to

A Provide examples of species that seem to contradict the competitive exclusion principle in natural settings

B point out a way in which these species coexist more easily than Paramecium species do

C draw a contrast between the resources available to fish and those on which trees depend

D indicate that one of each of these species will eventually displace all of the others it competes with

P3 Ecologist G. Evelyn Hutchinson provided one of the most important explanations for the coexistence of competing organisms. He proposed that each species has a fundamental niche , the complete range of environmental conditions, such as。。。。。余下托福阅读真题及题目省略！

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