25个考研英语阅读经典试题及答案(12)生物学类

25个考研英语阅读经典试题及答案(12)SAMPLE12[生物学类]题目序号题型归类第1题细节推导题型第2题写作手法题型第3题审题定位与中心主旨题型第4题词汇题型第5题审题定位题型Flatfish,suchastheflounder,areamongthefewvertebratesthatlackapproximatebilateralsymmetry(symmetryinwhichstructurestotheleftandrightofthebody’smidlinearemirrorimages).Moststrikingamongthemanyasymmetriesevidentinanadultflatfishiseyeplacement:beforematurityoneeyemigrates,sothatinanadultflatfishbotheyesareonthesamesideofthehead.Whileinmostspecieswithasymmetriesvirtuallyalladultssharethesameasymmetry,membersofthestarryflounderspeciescanbeeitherleft-eyed(botheyesontheleftsideofhead)orright-eyed.InthewatersbetweentheUnitedStatesandJapan,thestarryflounderpopulationsvaryfromabout50percentleft-eyedofftheUnitedStatesWestCoast,throughabout70percentleft-eyedhalfwaybetweentheUnitedStatesandJapan,tonearly100percentleft-eyedofftheJapanesecoast.Biologistscallthiskindofgradualvariationoveracertaingeographicrangea“cline”andinterpretclinesasstrongindicationsthatthevariationisadaptive,aresponsetoenvironmentaldifferences.Forthestarryflounderthisinterpretationimpliesthatageometricdifference(betweenfishthataremirrorimagesofoneanother)isadaptive,thatleft-eyednessintheJapanesestarryflounderhasbeenselectedfor,whichprovokesaperplexingquestion:whatistheselectiveadvantageinhavingbotheyesononesideratherthanontheother?Theeasewithwhichafishcanreversetheeffectofthesidednessofitseyeasymmetrysimplybyturningaroundhascausedbiologiststostudyinternalanatomy,especiallytheopticnerves,fortheanswer.Inallflatfishtheopticnervescross,sothattherightopticnerveisjoinedtothebrain’sleftsideandviceversa.Thiscrossingintroducesanasymmetry,asoneopticnervemustcrossaboveorbelowtheother.G.H.Parkerreasonedthatif,forexample,aflatfish’slefteyemigratedwhentherightopticnervewasontop,therewouldbeatwistingofnerves,whichmightbemechanicallydisadvantageous.Forstarryflounders,then,theleft-eyedvarietywouldbeselectedagainst,sinceinastarryfloundertheleftopticnerveisuppermost.TheproblemwiththeaboveexplanationisthattheJapanesestarryflounderpopulationisalmostexclusivelyleft-eyed,andnaturalselectionneverpromotesapurelylessadvantageousvariation.Asotherexplanationsprovedequallyuntenable,biologistsconcludedthatthereisnoimportantadaptivedifferencebetweenleft-eyednessandright-eyedness,andthatthetwocharacteristicsaregeneticallyassociatedwithsomeotheradaptivelysignificantcharacteristic.Thissituationisonecommonlyencounteredbyevolutionarybiologists,whomustoftendecidewhetheracharacteristicisadaptiveorselectivelyneutral.Asfortheleft-eyedandright-eyedflatfish,theirdifference,howeverstriking,appearstobeanevolutionaryredherring.1.Accordingtothetext,starryflounderdifferformmostotherspeciesofflatfishinthatstarryflounder[A]arenotbasicallybilaterallysymmetric.[B]donotbecomeasymmetricuntiladulthood.[C]donotallsharethesameasymmetry.[D]havebotheyesonthesamesideofthehead.2.Whichofthefollowingbestdescribestheorganizationofthetextasawhole?[A]Aphenomenonisdescribedandaninterpretationpresentedandrejected.[B]Ageneralizationismadeandsupportingevidenceissuppliedandweighed.[C]Acontradictionisnotedandaresolutionissuggestedandthenmodified.[D]Aseriesofobservationsispresentedandexplainedintermsofthedominanttheory.3.Thetextsuppliesinformationforansweringwhichofthefollowingquestions?[A]WhyareJapanesestarryfloundermostlyleft-eyed?[B]Whyshouldtheeye-sidednessinstarryflounderbeconsideredselectivelyneutral?[C]Whyhavebiologistsrecentlybecomeinterestedinwhetheracharacteristicisadaptiveorselectivelyneutral?[D]Howdotheeyesinflatfishmigrate?4.Whichofthefollowingismostclearlysimilartoaclineasitisdescribedinthesecondparagraphofthetext?[A]Avegetablemarketinwhichthevariousitemsaregroupedaccordingtoplaceoforigin.[B]Awheatfieldinwhichdifferentvarietiesofwheatareplantedtoyieldacropthatwillbringthemaximumprofit.[C]Aflowerstallinwhichthevariousspeciesofflowersarearrangedaccordingtotheirprice.[D]Ahousingdevelopmentinwhichthelengthofthefrontstrutssupportingtheporchofeachhouseincreasesashousesarebuiltupthehill.5.Whichofthefollowingphrasesfromthetextbestexpressestheauthor’sconclusionaboutthemeaningofthedifferencebetweenleft-eyedandright-eyedflatfish?[A]“Moststriking”(line3,paragraph1)[B]“variationisadaptive”(line2,paragraph2)[C]“mechanicallydisadvantageous”(line7,paragraph3)[D]“evolutionaryredherring”(line9,paragraph4)[答案与考点解析]1.【答案】C【考点解析】这是一道细节推导题。根据本题题干中的“mostotherspecies”可以把本题的答案信息来源确定在第一段的第三句，从第三句的主从句中可以归纳推导出本题的正确答案C。本句中的“while”一词的含义是“虽然、尽管”，用来表达事物之间的对照对比。考生在解题时一定要首先学会审题定位的基本功。2.【答案】A【考点解析】这是一道文章具体写作手法题。这是一道比较难的题型，需要考生对文章的叙述结构有深刻的理解。本文第一段介绍了一种现象，第二段和第三段是生物学家对这种现象的解释，第四段是本文作者对生物学家的解释提出否定。可见本题的正确选项是A。考生在解题时一定要注意文章的发展脉络。3.【答案】B【考点解析】本题是一道审题定位题型。本题的题干没有具体给出寻找答案信息的任何线索。在这种情况下考生一定要牢记原文作者的主要意图。具体来说，本文作者的主要意图是要否定一些生物学家对某种生物现象的解释。相关的内容出现在原文第四段的首句。如果考生能够认识到原文第四段首句在全文中的重要性，就找到了破解本题的方法，再把第三段的尾句和第四段的第二、三句通读并且仔细理解就会找出本题的正确答案B。当然这是一道比较难的题目，需要考生良好的答题素质。希望考生在迷失答题思路的时候，一定要多想一想从原文的中心主旨句和每段的段首句设法破解难题。4.【答案】D【考点解析】这是一道词汇理解题。根据原文中的“cline”一词可迅速把本题的答案信息确定在第二段第一句。第二段第一句中的“gradual”、“geographic”、“adaptive”和“environmentaldifferences”等词提供了本题的正确答案D。考生在阅读原文回答问题时，一定要学会识读原文中的相关重