高中英语必修6Module5Section2BackgroundinformationforModule5CloningWord文件下载.docx

高中英语必修6Module5Section2BackgroundinformationforModule5CloningWord文件下载.docx

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1.WhatisCloning?

Haveyoueverwishedyoucouldhaveacloneofyourselftodohomeworkwhileyouhittheskateparkorwentoutwithyourfriends?

Imagineifyoucouldreallydothat.Wherewouldyoustart?

●Whatexactlyiscloning?

Cloningisthecreationofanorganismthatisanexactgeneticcopyofanother.ThismeansthateverysinglebitofDNAisthesamebetweenthetwo!

Youmightnotbelieveit,buttherearehumanclonesamongusrightnow.Theyweren'

tmadeinalab,though:

they'

reidenticaltwins,creatednaturally.Below,we'

llseehownaturalidenticaltwinsrelatetomoderncloningtechnologies.

●Howiscloningdone?

YoumayhavefirstheardofcloningwhenDollytheSheepshoweduponthescenein1997.CloningtechnologieshavebeenaroundformuchlongerthanDolly,though.

Howdoesonegoaboutmakinganexactgeneticcopyofanorganism?

Thereareacoupleofwaystodothis:

artificialembryotwinningandsomaticcellnucleartransfer.Howdotheseprocessesdiffer?

（1）ArtificialEmbryoTwinning

Artificialembryotwinningistherelativelylow-techversionofcloning.Asthenamesuggests,thistechnologymimicsthenaturalprocessofcreatingidenticaltwins.

Openlargeversion

Innature,twinsoccurjustafterfertilizationofaneggcellbyaspermcell.Inrarecases,whentheresultingfertilizedegg,calledazygote,triestodivideintoatwo-celledembryo,thetwocellsseparate.Eachcellcontinuesdividingonitsown,ultimatelydevelopingintoaseparateindividualwithinthemother.Sincethetwocellscamefromthesamezygote,theresultingindividualsaregeneticallyidentical.

Artificialembryotwinningusesthesameapproach,butitoccursinaPetridishinsteadofinthemother'

sbody.Thisisacplishedbymanuallyseparatingaveryearlyembryointoindividualcells,andthenallowingeachcelltodivideanddeveloponitsown.Theresultingembryosareplacedintoasurrogatemother,wheretheyarecarriedtotermanddelivered.Again,sincealltheembryoscamefromthesamezygote,theyaregeneticallyidentical.

（2）SomaticCellNuclearTransfer

Somaticcellnucleartransfer,（SCNT）usesadifferentapproachthanartificialembryotwinning,butitproducesthesameresult:

anexactclone,orgeneticcopy,ofanindividual.ThiswasthemethodusedtocreateDollytheSheep.

WhatdoesSCNTmean?

Let'

stakeitapart:

Somaticcell:

Asomaticcellisanycellinthebodyotherthanthetwotypesofreproductivecells,spermandegg.Thesearealsocalledgermcells.Inmammals,everysomaticcellhastwopletesetsofchromosomes,whereasthegermcellsonlyhaveonepleteset.

Nuclear:

Thenucleusislikethecell'

sbrain.It'

sanenclosedpartmentthatcontainsalltheinformationthatcellsneedtoformanorganism.ThisinformationesintheformofDNA.It'

sthedifferencesinourDNAthatmakeeachofusunique.

Transfer:

Movinganobjectfromoneplacetoanother.

TomakeDolly,researchersisolatedasomaticcellfromanadultfemalesheep.Next,theytransferredthenucleusfromthatcelltoaneggcellfromwhichthenucleushadbeenremoved.Afteracoupleofchemicaltweaks,theeggcell,withitsnewnucleus,wasbehavingjustlikeafreshlyfertilizedzygote.Itdevelopedintoanembryo,whichwasimplantedintoasurrogatemotherandcarriedtoterm.

Thelamb,Dolly,wasanexactgeneticreplicaoftheadultfemalesheepthatdonatedthesomaticcellnucleustotheegg.Shewasthefirst-evermammaltobeclonedfromanadultsomaticcell.

2019-2020年高中英语必修6Module5Section3WordsandExpressionsfromModule5Clonding

clone

n.

1（biology）aplantorananimalthatisproducednaturallyorartificiallyfromthecellsofanotherplantoranimalandisthereforeexactlythesameasit2（sometimesdisapproving）apersonorthingthatseemstobeanexactcopyofanother:

Caroline’sbrothersgrinnedalongsideher,clonesoftheirfather.3（puting）aputerdesignedtoworkinexactlythesamewayasanother,usuallyonemadebyadifferentpanyandmoreexpensive

v.[vn]

1toproduceanexactcopyofananimaloraplantfromitscells:

AteamfromtheUKwerethefirsttosuccessfullycloneananimal.Dolly,theclonedsheep.2toillegallymakeanelectroniccopyofstoredinformationfromaperson’screditcardormobilephone/cellphonesothatyoucanmakepaymentsorphonecallsbuttheownerofthecardorphonereceivesthebill

terrify

v.（terrifies,terrifying,terrified,terrified）[vn]tomakesb.feelextremelyfrightened:

Flyingterrifiesher.

terrifying

adj.:

Itwasaterrifyingexperience.terrifyingly

adv.:

Themountainroadsareterrifyinglysteep.

wrinkle

1alineorsmallfoldinyourskin,