高考英语《流行话题 语境识词4500》Unit 75　The Concerns about Genetically Modified Food素材.doc

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1、高考英语《流行话题语境识词4500》Unit75　TheConcernsaboutGeneticallyModifiedFood素材Unit75　　TheConcernsaboutGeneticallyModifiedFood　　GeneticModification(GM)hasthepowertosavelivesthroughitsuseinmedicine,suchastheproductionofinsulinfordiabeticsorthetreatmentofgeneticdisorders.Thecurrent

2、outcrycomeswhenitisusedtoproducefood.Someofthesepublicconcernsreflectrealproblems,butothersarefuelledbymisinformationandover-dramatization.　　Thereisnothingnewaboutcropmodification;plantbreedershavebeendoingthissinceagriculturebegan.Thewonderfulrangeofapplesorpotatoes

3、wenowenjoyistheresultofcrossingdifferentvarieties.Cabbages,Brusselssprouts,cauliflower,kohlrabiandbroccolialloriginatedfromonebotanicalspecies.　　Modernmoleculebiologyhasenabledustogomuchfurther.Wecannowisolatethegenefromaparticularcharacteristicofanorganismandtransfe

4、rittoanotherspecies.Itisthispracticeoftransformingaplantwithaliengenes--perhapsfromananimalorbacterium--thatiscausingallthecontroversy.　　Therearefourmainconcerns.　　Scientistscannowtakeageneforresistancetoparticularherbicideandtransplantittoacrop:whentheseplantsarespr

5、ayedwithweedkiller,theweedsweredestroyedwhilethecropisunharmed.Aprimeconcernistheharmfuleffectthiscouldhaveonthebiodiversityoffarmland,wheresomanyinsects,birdsandotheranimalsdependon"weed"species.　　AnotherfearisthataliengenesfromaGMplantcouldescapeintoawildpopulation

6、ofarelatedspecies.Sinceplantsarefertilizedbypollencarriedthroughair,oftenforlongdistances,thisisentirelypossible.Awildspeciesmodifiedinthiswaywithpesticideresistancecouldbecomeasuperweed,whileaspeciesthatbecameunnaturallyresistanttoanimalscoulddisruptthefoodchain.　　T

7、hethirdworryconcernsaproposaltoproduceseedsforcerealsthatcannotproducenextyear'sseeds.This"terminatortechnology"wouldbenefitseedcompanies,sincefarmswouldbeforcedtobuynewseedsannually.Butthesametechnologycouldbedevastatingtosomefarmersinthedevelopingcountrieswhodepend

8、onsavingseedsfornextyear'scrop.Fortunatelythistechnologyisnotyetinuseandtherehasbeenstrongpressuretoabandonit.　　Itisunlikelythatthe