GMAT考试资料：GWD试题合集（三十七）.

　　以下将为正在备战GMAT考试的同学们整理一些经典的GMAT阅读试题，并分多个合集推出，希望能够为正在备考GMAT考试的考生提供或多或少的帮助。

　　20. T-3-Q25-Q27两派学者对突变基因的不同认识和态度

　　Researchers studying how genes

　　control animal behavior have had

　　to deal with many uncertainties. In

　　the first place, most behaviors are

　　(5) governed by more than one gene,

　　and until recently geneticists had no

　　method for identifying the multiple

　　genes involved. In addition, even

　　when a single gene is found to control

　　(10) a behavior, researchers in different

　　fields do not necessarily agree that it is

　　a “behavioral gene.” Neuroscientists,

　　whose interest in genetic research is to

　　understand the nervous system (which

　　(15) generates behavior), dine the term

　　broadly. But ethologists ― specialists

　　in animal behavior― are interested

　　in evolution, so they dine the term

　　narrowly. They insist that mutations in

　　(20) a behavioral gene must alter a specific

　　normal behavior and not merely make

　　the organism ill, so that the genetically

　　induced behavioral change will provide

　　variation that natural selection can act

　　(25) upon, possibly leading to the evolution

　　of a new species. For example, in the

　　fruit fly, researchers have identified

　　the gene Shaker, mutations in which

　　cause flies to shake violently under

　　(30) anesthesia. Since shaking is not

　　healthy, ethologists do not consider

　　Shaker a behavioral gene. In con-

　　trast, ethologists do consider the gene

　　period (per), which controls the fruit

　　(35) fly’s circadian (24 hour) rhythm, a

　　behavioral gene because files with

　　mutated per genes are healthy, they

　　simply have different rhythms.

　　T-3-Q25

　　The passage suggests that neuroscientists would most likely consider Shaker to be which of the following?

　　A. An example of a behavioral gene

　　B. One of multiple genes that control a single behavior

　　C. A gene that, when mutated, causes an alteration in a specific normal behavior without making the organism ill

　　D. A gene of interest to ethologists but of no interest to neuroscientists

　　E. A poor source of information about the nervous system

　　ethologists do not consider Shaker a behavioral gene 取非

　　T-3-Q26

　　It can be inferred from the passage that which of the following, if true, would be most likely to influence ethologists’ opinions about whether a particular gene in a species is a behavioral gene?

　　A. The gene is found only in that species.

　　B. The gene is extremely difficult to identify.

　　C. The only fect of mutations in the gene is to make the organism ill.

　　D. Neuroscientists consider the gene to be a behavioral gene.

　　E. Geneticists consider the gene to be a behavioral gene.

　　They insist that mutations in a behavioral gene must alter a specific normal behavior and not merely make the organism ill

　　T-3-Q27

　　The primary purpose of the passage is to

　　A. summarize findings in an area of research

　　B. discuss different perspectives on a scientific question

　　C. outline the major questions in a scientific discipline

　　D. illustrate the usulness of investigating a research topic

　　E. reconcile differences between two dinitions of a term

　　以上就是本期GMAT试题的所有内容，考生可以此为据并进行针对性的练习，逐步掌握GMAT阅读的解题规律及技巧，以达到迅速提高GMAT考试成绩的目的。 相关链接：

1.GMAT考试资料：GWD试题合集（三十六）

2.GMAT考试资料：GWD试题合集（三十五）

3.GMAT考试资料：GWD试题合集（三十四）

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