1、精選優(yōu)質(zhì)文檔-傾情為你奉上精選優(yōu)質(zhì)文檔-傾情為你奉上專心-專注-專業(yè)專心-專注-專業(yè)精選優(yōu)質(zhì)文檔-傾情為你奉上專心-專注-專業(yè)25個考研英語閱讀經(jīng)典試題及答案(12)SAMPLE 12生物學類題目序號題型歸類第1題細節(jié)推導題型第2題寫作手法題型第3題審題定位與中心主旨題型第4題詞匯題型第5題審題定位題型Flatfish, such as the flounder, are among the few vertebrates that lack approximate bilateral symmetry (symmetry in which structures to the left and

2、 right of the bodys midline are mirror images). Most striking among the many asymmetries evident in an adult flatfish is eye placement: before maturity one eye migrates, so that in an adult flatfish both eyes are on the same side of the head. While in most species with asymmetries virtually all adul

3、ts share the same asymmetry, members of the starry flounder species can be either left-eyed (both eyes on the left side of head) or right-eyed. In the waters between the United States and Japan, the starry flounder populations vary from about 50 percent left-eyed off the United States West Coast, th

4、rough about 70 percent left-eyed halfway between the United States and Japan, to nearly 100 percent left-eyed off the Japanese coast.Biologists call this kind of gradual variation over a certain geographic range a “cline” and interpret clines as strong indications that the variation is adaptive, a r

5、esponse to environmental differences. For the starry flounder this interpretation implies that a geometric difference (between fish that are mirror images of one another) is adaptive, that left-eyedness in the Japanese starry flounder has been selected for, which provokes a perplexing question: what

6、 is the selective advantage in having both eyes on one side rather than on the other?The ease with which a fish can reverse the effect of the sidedness of its eye asymmetry simply by turning around has caused biologists to study internal anatomy, especially the optic nerves, for the answer. In all f

7、latfish the optic nerves cross, so that the right optic nerve is joined to the brains left side and vice versa. This crossing introduces an asymmetry, as one optic nerve must cross above or below the other. G. H. Parker reasoned that if, for example, a flatfishs left eye migrated when the right opti

8、c nerve was on top, there would be a twisting of nerves, which might be mechanically disadvantageous. For starry flounders, then, the left-eyed variety would be selected against, since in a starry flounder the left optic nerve is uppermost.The problem with the above explanation is that the Japanese

9、starry flounder population is almost exclusively left-eyed, and natural selection never promotes a purely less advantageous variation. As other explanations proved equally untenable, biologists concluded that there is no important adaptive difference between left-eyedness and right-eyedness, and tha

10、t the two characteristics are genetically associated with some other adaptively significant characteristic. This situation is one commonly encountered by evolutionary biologists, who must often decide whether a characteristic is adaptive or selectively neutral. As for the left-eyed and right-eyed fl

11、atfish, their difference, however striking, appears to be an evolutionary red herring.1. According to the text, starry flounder differ form most other species of flatfish in that starry flounderA are not basically bilaterally symmetric.B do not become asymmetric until adulthood.C do not all share th

12、e same asymmetry.D have both eyes on the same side of the head.2. Which of the following best describes the organization of the text as a whole?A A phenomenon is described and an interpretation presented and rejected.B A generalization is made and supporting evidence is supplied and weighed.C A cont

13、radiction is noted and a resolution is suggested and then modified.D A series of observations is presented and explained in terms of the dominant theory.3. The text supplies information for answering which of the following questions?A Why are Japanese starry flounder mostly left-eyed?B Why should th

14、e eye-sidedness in starry flounder be considered selectively neutral?C Why have biologists recently become interested in whether a characteristic is adaptive or selectively neutral?D How do the eyes in flatfish migrate?4. Which of the following is most clearly similar to a cline as it is described i

15、n the second paragraph of the text?A A vegetable market in which the various items are grouped according to place of origin.B A wheat field in which different varieties of wheat are planted to yield a crop that will bring the maximum profit.C A flower stall in which the various species of flowers ar

16、e arranged according to their price.D A housing development in which the length of the front struts supporting the porch of each house increases as houses are built up the hill.5. Which of the following phrases from the text best expresses the authors conclusion about the meaning of the difference b

17、etween left-eyed and right-eyed flatfish?A “Most striking” (line 3, paragraph 1)B “variation is adaptive” (line 2, paragraph 2)C “mechanically disadvantageous” (line 7, paragraph 3)D “evolutionary red herring” (line 9, paragraph 4)答案與考點解析1. 【答案】C【考點解析】這是一道細節(jié)推導題。根據(jù)本題題干中的“most other species”可以把本題的答案信息

18、來源確定在第一段的第三句，從第三句的主從句中可以歸納推導出本題的正確答案C。本句中的“while”一詞的含義是“雖然、盡管”，用來表達事物之間的對照對比?？忌诮忸}時一定要首先學會審題定位的基本功。2. 【答案】A【考點解析】這是一道文章具體寫作手法題。這是一道比較難的題型，需要考生對文章的敘述結構有深刻的理解。本文第一段介紹了一種現(xiàn)象，第二段和第三段是生物學家對這種現(xiàn)象的解釋，第四段是本文作者對生物學家的解釋提出否定。可見本題的正確選項是A?？忌诮忸}時一定要注意文章的發(fā)展脈絡。3. 【答案】B【考點解析】本題是一道審題定位題型。本題的題干沒有具體給出尋找答案信息的任何線索。在這種情況下考生

19、一定要牢記原文作者的主要意圖。具體來說，本文作者的主要意圖是要否定一些生物學家對某種生物現(xiàn)象的解釋。相關的內(nèi)容出現(xiàn)在原文第四段的首句。如果考生能夠認識到原文第四段首句在全文中的重要性，就找到了破解本題的方法，再把第三段的尾句和第四段的第二、三句通讀并且仔細理解就會找出本題的正確答案B。當然這是一道比較難的題目，需要考生良好的答題素質(zhì)。希望考生在迷失答題思路的時候，一定要多想一想從原文的中心主旨句和每段的段首句設法破解難題。4. 【答案】D【考點解析】這是一道詞匯理解題。根據(jù)原文中的“cline”一詞可迅速把本題的答案信息確定在第二段第一句。第二段第一句中的“gradual”、“geograph

20、ic”、“adaptive”和“environmental differences”等詞提供了本題的正確答案D?？忌陂喿x原文回答問題時，一定要學會識讀原文中的相關重要詞語。5. 【答案】D【考點解析】這是一道審題定位題。根據(jù)題干中的“the authors conclusion”可將本題的答案信息迅速確定在尾段，確切地說就是尾段的最后一句。考生一定要清楚原文作者的結論一般會出現(xiàn)在全文的尾段。本題的正確答案應該是涉及到尾段的選項D。參考譯文鲆魚，例如比目魚，是少數(shù)左右兩側不太對稱的脊椎動物之一(左右兩側對稱指的是身體中線左右兩邊的結構為鏡象反射)。在成年的比目魚所具有的眾多明顯的不對稱現(xiàn)象中，最令人震驚的是它的眼睛的位置：在成熟以前，一只眼睛會移動，結果是成年比目魚的兩只眼睛都移動到頭部的同一側。在大多數(shù)非對稱的物種中，成年個體的非對稱性看起來都是相同的，但星形比目魚種的成員則既可以是眼在左側的(兩只眼都在頭部的左側)，也可以是眼在右側的。在美國和日本之間的水域中，星形比目魚的群體組成不斷變化，在美國西海岸附近，50%是眼在左側的，在美國和日本之間的中間位置，70%是眼在左側的，而到了靠近日本海岸的地方，則幾乎百分之百都是眼在左側的了。生物學家將這種在特定地理區(qū)域范圍內(nèi)的逐漸變化