高考英语一轮复习 unit2 cloning导学案 新人教版选修8

《高考英语一轮复习 unit2 cloning导学案 新人教版选修8》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、河北省武邑中学2016届高考英语一轮复习Unit2Cloning导学案新人教版选修8ReadingCLONING:WHEREISITLEADINGUS?Cloninghasalwaysbeenwithusandisheretostay.Itisawayofmakinganexactcopyofanotheranimalorplant.Ithappensinplantswhengardenerstakecuttingsfromgrowingplantstomakenewones.Italsohappensinanimals1.________twinsidenticalinsexandapp

2、earanceareproducedfromthesameoriginalegg.Thefactisthatthesearebothexamplesofnaturalclones.Cloninghastwomajoruses.Firstlygardenersuseitallthetimetoproducecommercialquantitiesofplants.Secondly,itisvaluableforresearchonnewplantspeciesandformedicalresearchonanimals.Cloningplantsisstraightforward2.____

3、___cloninganimalsisverycomplicated.Itisadifficulttask3.______________(undertake).Manyattemptstoclonemammalsfailed.Butatlastthedeterminationandpatienceofthescientistspaidoffin1996withabreakthrough—thecloningofDollythesheep.Theprocedureworkslikethis:1.FemalesheepAprovidesaneggcell.2.Thenucleusisremo

4、vedfromtheeggcell.3.Theeggcellisreadyforanewnucleus.4.FemalesheepBprovidesasomaticcellfortheclone.Thenucleusofthiscellcontainsallthegenesneededtoproduceanewsheep.5.Thenucleusistakenoutofthesomaticcell.6.ThenucleusfromsheepBandtheeggcellfromsheepAarejoinedusingelectricity.7.Thecelldividesandgrowsin

5、toanembryo.8.TheembryoisputintofemalesheepC,whobecomesthecarrieroftheclone.9.ThelambisthecloneofthedonatedcellfromSheepBwhichprovidedthenucleus.Ontheonehand,thewholescientificworldfollowedtheprogressofthefirstsuccessfulclone,Dollythesheep.Thefactthatsheseemedtodevelopnormallywasvery4._____________

6、(encourage).Thencamethedisturbingnews5.__________Dollyhadbecomeseriouslyill.Cloningscientistswerecastdown6._________(find)thatDolly’sillnessesweremoreappropriatetoamucholderanimal.AltogetherDollylivedsixandahalfyears,halfthe7.________(long)ofthelifeoftheoriginalsheep.8._________[尽管]herproblems,Dol

7、lysuccessfullyproducedalambina9.___________(nature)birth.Sadlythesamearbitraryfateaffectedotherspecies,suchasclonedmice.Thequestionsthatconcernedallscientistswere:“Wouldthisbe10._____majordifficultyforallclonedan