資源描述:
《GRE issue寫(xiě)作之自己總結(jié)的萬(wàn)能例子》由會(huì)員上傳分享,免費(fèi)在線(xiàn)閱讀,更多相關(guān)內(nèi)容在行業(yè)資料-天天文庫(kù)。
1、RenaissanceForexample,thehelplessfatecanbefeltfromthetragedyworks,writtenbyShakespeare.MonaLisa,createdbyBeethoven,revealedthemysteriousandimplicitsmile.Althoughworkscompletedbydifferentartistsandwritersrevealedslightvariationsintheaccess,performingform,andsocialaspectfocusi
2、ngon,asfarascommonthemeandhiddenideaswereconcerned,theobvioussimilriestoeachotherseemedmuchmorethananyoftheminutedifferences,namely,resistingthefeudalizationandcorruptinstitutionandenlighteningfreedomofhumanbeing.Thisiscalled“Renaissance”inthehistory.Geneticengineering迄今為止,基
3、因工程還沒(méi)有用于人體,但已在從細(xì)菌到家畜的幾乎所有非人生命物體上做了實(shí)驗(yàn),并取得了成功。事實(shí)上,所有用于治療糖尿病的胰島素都來(lái)自一種細(xì)菌,其DNA中被插入人類(lèi)可產(chǎn)生胰島素的基因,細(xì)菌便可自行復(fù)制胰島素?;蚬こ碳夹g(shù)使得許多植物具有了抗病蟲(chóng)害和抗除草劑的能力;在美國(guó),大約有一半的大豆和四分之一的玉米都是轉(zhuǎn)基因的。目前,是否該在農(nóng)業(yè)中采用轉(zhuǎn)基因動(dòng)植物已成為人們爭(zhēng)論的焦點(diǎn):支持者認(rèn)為,轉(zhuǎn)基因的農(nóng)產(chǎn)品更容易生長(zhǎng),也含有更多的營(yíng)養(yǎng)(甚至藥物),有助于減緩世界范圍內(nèi)的饑荒和疾病;而反對(duì)者則認(rèn)為,在農(nóng)產(chǎn)品中引入新的基因會(huì)產(chǎn)生副作用,尤其是會(huì)破壞環(huán)境?!≌\(chéng)然,
4、仍有許多基因的功能及其協(xié)同工作的方式不為人類(lèi)所知,但想到利用基因工程可使番茄具有抗癌作用、使鮭魚(yú)長(zhǎng)得比自然界中的大幾倍、使寵物不再會(huì)引起過(guò)敏,許多人便希望也可以對(duì)人類(lèi)基因做類(lèi)似的修改。畢竟,胚胎遺傳病篩查、基因修復(fù)和基因工程等技術(shù)不僅可用于治療疾病,也為改變諸如眼睛的顏色、智力等其他人類(lèi)特性提供了可能。比如,運(yùn)用此技術(shù),可使患兒的父母生一個(gè)和患兒骨髓匹配的孩子,然后再通過(guò)骨髓移植來(lái)治愈患兒。Sofar,geneticengineeringhasnotbeenusedinhuman,butithasachievedsuccessfulexperi
5、mentinalmostalltheobjectsonnon-humanlife--frombacteriatolivestockalready.Infact,alltheinsulintreatmentfordiabetescomefromakindofbacteriawhichcanbeinsertedintoahumangenestomakecopiesofinsulinbybacteriaoneself.Geneticengineeringtechnologymakesmanyplantshavethedisease-resistant
6、abilityandherbicide,IntheUSA,abouthalfofsoybeanandaquarterofcornisgeneticallymodified.Atpresent,whetherthetransgenicplantsusedinagriculturehasbecomethefocusofdebate,transgenicsupportersthink:theagriculturalisfastertogrowth,andeasiertocontainmorenutrition(evenmedicine),tohelp
7、slowdownworldwidefamineanddisease,Butopponentsargued,introducingnewgenesintoagriculturalwilloccursideeffects,especiallydestroytheenvironment.Advantage:Admittedly,ethicistrejectedtheinnovativedevelopmentofgeneticengineeringbecause,althoughitresolvedsomeproblems,italsoproduced
8、newcomplications.Nevertheless,therearestillmanygenesfunctionandworkprincipl