高中英语 Unit2第6课时（文化背景知识）教案 新人教版选修8VIP免费

英语高二下人教版新课标选修8Unit2第6课时教案（文化背景知识）I.Readingcomprehension:Hello,Dolly!Britishscientistshavedonesomethingthatmanypeoplethoughtwasimpossible:theycreatedthefirstcloneofanadultmammal.Theclone,namedDolly,isaseven-month-oldsheep,grownfromacellofanadultfemalesheep.Whatisaclone?Acloneisacopy,ageneticcopy.Genesaretheinstructionsforlife.Theytellacellwhattodoandhowtodoit.Genesmakeeachindividualplantoranimaldifferentandunique.Butaclonehasthesamegenesastheoriginalorganism.Cloningisnotnew.Plantshavebeenclonedforcenturies.Newplantsareoftengrownfromcuttingsfromanotherplant.Also,plantslikepineapples,strawberriesandcarnationsaresometimescloned.Onebenefitofcloningisthatwecanmakemanycopiesofthebestandhealthiestplants.Ithasbeenmuchmoredifficulttocloneanimals.Frogshavebeencloned,buttheydiedastadpoles,neverlivinglongenoughtobecomeadultfrogs.Mice,sheepandcattlehavebeenclonedfromembryos.ButDollyisthefirsthealthycloneofanadultmammal.Howdidtheydoit?(1)Anunfertilizedeggwastakenfromasheep.(2)Theeggnucleuswasremoved.(3)Acellwastakenfromtheudderofapregnantsheep.Itwas“starved”,sothatitstoppedgrowing.(4)Thetwocellswerecombinedintooneandthenimplantedinathirdsheep,whereitgrewnormally.(5)Theclonewasborn.Itwasgeneticallyidenticaltothepregnantsheepinstep(3).Thissoundsmucheasierthanitactuallywas.Toendupwithoneclone,thescientistsstartedwith277uddercells.Andtheyneededinawaytomaketheeggcellacceptanewnucleus.Theydidthatbystarvingthecellinstep(3).Itmaysoonbepossibletoclonemanytypesofanimals.Willwealsobeabletoclonehumanorgans,orevenwholehumanbeings?Wehaveonlybeguntothinkaboutthemoralityofcloningtechnology.Maybethequestiontoaskisnotwhetherwecanclonehumans,butinstead,shouldweclonehumans?1.Dollyisasheepbecausesheisgrownfromacellofanadultfemalesheep_____.A.thathasnotherfatherB.thathasnothermotherC.thathasnoparentsD.thathasnotanytail2.TellwhichofthefollowingstatementsisTRUE.A.Onlyplantscanbecloned.B.Onlystrawberriesandcarnationscansometimesbecloned.C.Animalsandplantshavequitealonghistoryofcloning.D.Genescantellacellwhattodoandhowtodoitduringcloning.3.Fromthefourthparagraphwecanknowthat_____.A.atadpoleistheearlystageofagrown-upfrogB.atadpoleisafrogwithoutatailC.atadpoleisapoolwherefrogscanliveD.atadpoleisacloneofanadultmammal4.WhatistherightorderintheprocessofthecloneofDolly?a.Takinganunfertilizedeggfromanadultfemalesheep.b.Removingtheegg’snucleus.c.Combiningthetwocellsintooneandthenimplantingitinathirdsheep.d.Takingacellfromtheudderofapregnantsheep.A.abcdB.cabdC.abdcD.dcba答案与分析本文是科普时文阅读。全文讲述了克隆羊多莉的出生过程。1.C从文章中可以看出，多莉是从一只成年羊的细胞中克隆出来的，所以它根本没有父母，而是那只羊的一个翻版。A项“它没有父亲”、B项"它没有母亲"说得太片面，D项“它没有尾巴”不符合题意。2.D题意为“下面哪句话是对的”，D项“基因在克隆过程中可以告诉细胞做什么及如何去做”，文中第二段正是说的这个意思。第三段指植物可以克隆，第四段指动物也可以克隆，所以选项A“只有植物可以克隆”不正确。从文中第三段可知菠萝也是可以克隆的，所以B项“只有草莓和康乃馨有时可以克隆”不正确。第三段中指植物已有几个世纪的克隆历史，而没有提到动物的克隆历史，所以与C项“动、植物都有一个相当长的克隆历史”与题意不符。3.A文中第四段第二句中说：人们曾经克隆过青蛙，但在蝌蚪阶段就死了，并没有活到成年青蛙阶段，所以我们可以判断，蝌蚪是青蛙的早期形态，故A项“蝌蚪是成年青蛙的早期形态”正确。B项“蝌蚪是没有尾巴的青蛙”、C...