《教材全解》2014-2015学年高中英语外研版选修六参考文章：M5 WHAT IS CLONING-豆柴文库

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WhatisCloning?

Cloning(克隆技术)isthemostattractivestoryofthenewbiotechnologies(生物技术)andtheonewhichcausesthemostheateddiscussionoveritsworth.Hereareanswerstothemostcommonquestionsaboutcloning.

1.Whatiscloning?

CloningisthecreationofcellsorwholeanimalsusingDNA(脱氧核糖核酸)fromasingle"parent",bypassing(绕道而行)thenormalreproductiveprocess.TheclonehasthesameDNAtotheparent.

2.Iscloningunnatural?

No.Clonesarealwaysproducedbynaturalmeansintheshapeofidenticaltwins(同卵孪生).

3.Howareclonescreated?

ThemostcommonprocesstakesDNAfromonecellandputsinahollowed-out(挖空的；掏空的)egg.ChemicalsandelectricityarethenusedtoencouragethenewDNAtofusewith(与…合并)theegganddevelopintoanembryo(胎儿).Thistechniqueiscallednucleartransfer(核迁移).

4.WhywasDolly(世界上的第一只克隆羊)important?

Thesheepwasthefirstmammal(哺乳动物)tobeclonedusingDNAtakenfromanadultcell.Previously,animalshadonlybeenclonedusingembryocellswhichalreadyhavethepotentialtobecomeacompleteembryoinitsownright(继承父母的).ThebigbreakthroughwithDollywastomakeaclonefromanordinary,adultcell-inthiscasefromafemalegoat'sudder(乳房).

5.Areclonesnormal,healthyanimals?

Dollyis,butscientistdonotyetknowwhetherthisistheexception(例外)ortherule.Someearlyevidencesuggestthatclonesmayhavehealthproblemsandthattheymayageprematurely(早衰的，未老先衰).

6.Couldahumanclonebebornsoon?

Intheory,yes.ThetechniquesusedtocreateDollycouldbeappliedto(运用；适用)humans.Butthetechnologyofreproductivecloningisstillinitsveryearlystagesandthereismuchthatscientistsdonotunderstand.Ittookmorethan200attempts(努力；试验)tomakeDolly.Theotherembryosfailedtoimplant(播种)inthesurrogate(代理；代替)motherorweremiscarried.Evenifaclonemakesittobirth,atpresentithasaverylowchanceofsurvivingintoadultlife.

7.Hasanyonesaidtheywillmakelivehumanclones?

Anumberofpeoplehave,includingChicagophysicistDrRichardSeed.However,fewexpertsbelievethatthesepeoplehavetheskillstosucceed.

8.Arethereanybenefitsfromcloning?

Yes.Thetechniquesusedhavealreadydemonstrated(展示)benefits.Polly,anothersheepcloneattheRoslinInstituteinEdinburghhashadahumangene(基因)in