GMAT考试资料：GWD试题合集（三）.

　　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。

　　2. GWD-1-Q25 to Q28生理因素和环境因素对硅藻生物钟产生的影响

　　Recently biologists have been

　　interested in a tide-associated

　　periodic behavior displayed by

　　Line the diatom Hantzschia virgata, a

　　(5) microscopic golden-brown alga that

　　inhabits that portion of a shoreline

　　washed by tides (the intertidal zone).

　　Diatoms of this species, sometimes

　　called “commuter” diatoms, remain

　　(10) burrowed in the sand during high

　　tide, and emerge on the sand sur-

　　face during the daytime low tide.

　　Just bore the sand is inundated by

　　the rising tide, the diatoms burrow

　　(15) again. Some scientists hypothesize

　　that commuter diatoms know that it

　　is low tide because they sense an

　　environmental change, such as an

　　alteration in temperature or a change

　　(20) in pressure caused by tidal move-

　　ment. However, when diatoms are

　　observed under constant conditions

　　in a laboratory, they still display

　　periodic behavior, continuing to bur-

　　(25) row on schedule for several weeks.

　　This indicates that commuter diatoms,

　　rather than relying on environmental

　　cues to keep time, possess an inter-

　　nal pacemaker or biological clock

　　(30) that enables them to anticipate peri-

　　odic changes in the environment.

　　A commuter diatom has an unusu-

　　ally accurate biological clock, a

　　consequence of the unrelenting

　　(35) environmental pressures to which

　　it is subjected; any diatoms that do

　　not burrow bore the tide arrives

　　are washed away.提出现象及其研究

　　This is not to suggest that the

　　(40) period of this biological clock is

　　immutably fixed. Biologists have

　　concluded that even though a

　　diatom does not rely on the envi-

　　ronment to keep time, environmental

　　(45) factors—including changes in the

　　tide’s hydrostatic pressure, salin-

　　ity, mechanical agitation, and

　　temperature—can alter the period

　　of its biological clock according to

　　(50) changes in the tidal cycle. In short,

　　the relation between an organism’s

　　biological clock and its environment

　　is similar to that between a wristwatch

　　and its owner: the owner cannot

　　(55) make the watch run faster or slower,

　　but can reset the hands. However,

　　this relation is complicated in intertidal

　　dwellers such as commuter diatoms

　　by the fact that these organisms are

　　(60) exposed to the solar-day cycle as

　　well as to the tidal cycle, and some-

　　times display both solar-day and

　　tidal periods in a single behavior.

　　Commuter diatoms, for example,

　　(65) emerge only during those low tides

　　that occur during the day.环境因素对其生物钟的影响

　　现象解释

　　逻辑简图：

　　1P: recently biologist interested in T behavior of HV. Some hypothesis… however… indicate, rather than, possess..

　　2P: not suggest fix. Biologist conclude environmental factors can alter

　　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（二）

2.GMAT考试资料：GWD试题合集（一）

3.浅析GMAT阅读的提升技巧

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