Module 2 DNA the secret of life Period One Introduction 课件

《Module 2 DNA the secret of life Period One Introduction 课件》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、Currentlytherearesome20,000chemicalsinuse,butthescientistsonlyhavedetailedinformationonaround1,000ofthem.ToseetheadvantagesofGMfoodyouhaveonlytoconsidertherecentpressrevelationthattheaveragelettucereceiveselevenpesticideapplicationsbeforeitreachesthesupermarketshelf.Module2DNAthesecretofli

2、fePeriodOneIntroduction&ReadingandVocabulary课件话题美文欣赏I'msurechemicalsandtheirrolesindiseasewillbecomeabigissueinthenextcenturyasthepopulationofthedevelopedworldworriesincreasinglyaboutitshealth.ThereasonGMfoodwillnotgoawayisthatweneedathreefoldincreaseinfoodproductionbytheyear2050tokeeppace

3、withtheworld'spredictedpopulationgrowthtotenorelevenbillion.It'snotjustaquestionofmoremouthstofeedeither.Whatisoftenforgottenisthatalltheseextrapeoplewilltakeupspace,reducingtheoveralllandavailableforagriculture.Theworldhas800millionhungrypeople.Untilnow,foodsupplieshavebeenincreasedbyimpr

4、ovedvarieties,pesticidesandartificialfertilizers:thegreenrevolution.Nowwe'reontheedgeofanewrevolution:ageneticone.ItmaywellbethatinthelongtermitisthedevelopingworldthatbenefitsmostfromGMfoods.It'struethatforthenexttenyearsorsoGMcropsmaybetooexpensive.Butthelessonofpersonalcomputersisapplic

5、ablehere－oncethetechnologyhasbeendevelopedformoneyspinningcrops,likemaize,soybeansandcotton,itwillfilterdownandbecomeaffordableforall.Thisdoesn'tmean,unfortunately,thatfamineswilldisappear,butseverityanddurationwillbehelpedbyanimprovedabilitytoproduceanddistributefood.Aswemoveintothisnewer

6、aofagriculturewe'reembarkingonanexperiment.Butrememberthattheworldhasseenanumberofexperimentsbefore.Wehavebeenrefiningspeciesofwheatforseveralthousandyears.Geneticengineerslikemearenotdoinganythingasdramaticasmakingacabbageintoacauliflower,ashasbeendonebyplantbreedersinthepast.We'resimplyt

7、appingintothewholegenepool,ratherthanconcentratingononespeciesatatime.1．Accordingtothepassage,wecanseethattheauthorhasa/anattitudetowardsGMfood.A．disappointedB．indifferentC．hopefulD．uncertainReadthepassageandchoosethebestanswer.2．Whichofthefollowingstatementsi