冀教版九年級(jí)全冊(cè)Unit5Lesson29教案

Unit5LookintoScienceLesson29【教學(xué)目標(biāo)】1．記憶單詞DNA,blueprint,general,complex,twin,repeat,pattern,identify,related,grandson,granddaughter,instruction;短語ingeneral,exceptfor,erelatedto,billionsof.2．掌握重點(diǎn)句型:（1）Ingeneral,blueprintisadrawingthatshowshowtoputahousetogetherwithmanydifferentparts.（2）Butbuildingalivingthingisfarmorecomplexthanbuildingahouse.（3）YouhaveyourownuniqueDNA,butitrepeatspatternsfromyourparents'DNA.（4）FromyourDNA,scientistscanidentifynotonlyyou,butalsopeoplewhoarerelatedtoyou.3．能夠用英語向他人介紹自己所知道的有關(guān)DNA的知識(shí).4．能夠理解課文內(nèi)容并回答課后的問題.【教學(xué)內(nèi)容】1．學(xué)會(huì)并能正確使用單詞及短語:DNA,blueprint,general,complex,twin,repeat,pattern,identify,related,grandson,granddaughter,instruction,ingeneral,exceptfor,berelatedto,billionsof.2．能夠運(yùn)用下列句型:（1）Ingeneral,blueprintisadrawingthatshowshowtoputahousetogetherwithmanydifferentparts.（2）Butbuildingalivingthingisfarmorecomplexthanbuildingahouse.（3）YouhaveyourownuniqueDNA,butitrepeatspatternsfromyourparents'DNA.（4）FromyourDNA,scientistscanidentifynotonlyyou,butalsopeoplewhoarerelatedtoyou.【教學(xué)重難點(diǎn)】1．能夠正確應(yīng)用本課的重點(diǎn)詞匯:DNA,blueprint,general,complex,twin,repeat,pattern,identify,related,grandson,granddaughter,instruction;掌握短語ingeneral,exceptfor,berelatedto,billionsof.2．能夠用英語向他人介紹自己所知道的有關(guān)DNA的知識(shí).【教學(xué)思路】思路一:以"DNA"為主題.通過展示圖片,詢問學(xué)生們"他們看起來一樣嗎?為什么一樣?他們?為什么不同?"引導(dǎo)學(xué)生們發(fā)現(xiàn)他們看起來相似的原因是由于DNA.通過設(shè)置學(xué),激發(fā)他們的學(xué)習(xí)興趣,調(diào)動(dòng)他們的積極性和主動(dòng)性:以"DNA"為主題.通過師生對(duì)話,直接導(dǎo)入本課話題DNA.通過小組合作探究,共同解決疑難看起來不同嗎生感興趣的話題導(dǎo)入新課.思路二,找出文中的重點(diǎn)短語和句子.【教學(xué)準(zhǔn)備】教師在課前設(shè)計(jì)教學(xué)PPT,準(zhǔn)備錄音機(jī)和磁帶,多媒體等.【教學(xué)過程】Ⅰ．LeadinLeadingin情景1T:Hello,class.Todaywe'lllearnLesson29.(TheteachershowstwopicturesonPPT.)Pleaselookatthepictures.Aretheylookthesame?Aretheredifferencesbetweenthem?S1:...T:Whydosomestudentslookdifferent?Andwhydocousinslooksimilar?Ss:BecauseofDNA.T:Welldone.Nowlet'slearnLesson29:DNA—TheStoryofYou.設(shè)計(jì)意圖:通過展示圖片,設(shè)置學(xué)生感興趣的問題,引出本課話題——DNA.激發(fā)了學(xué)生的學(xué)習(xí)興趣.Leadingin情景2T:Goodmorning/afternoon,everyone.WhatisDNA?WhatdoesDNAstandfor?S1:DNAissomethingthatalllivingthingshave.S2:DNAcarriesthegeneticinformationthatmakeseverylivingthingwhatitis.T:Verygood.DNAisshortforthefullscientificterm"deoxyribonucleicacid".That'shardtosay.DNAismucheasier.EverylivingthinghasitsownDNA.DNAholdstheinformationandinstructionsforcreatingalivingthing.Forexample,IhavestraightblackhairbecausepartoftheinstructionsinmyDNAwastogivemestraightblackhair.Mygrandmotherhasthesamestraightblackhair.Ihavepartofmygrandmother'sDNA.設(shè)計(jì)意圖:教師采用直接導(dǎo)入的方法,引出本課話題——DNA,使學(xué)生很直觀地進(jìn)入本課的學(xué)習(xí),為下面的學(xué)習(xí)奠定基礎(chǔ).Ⅱ．PresentationTheteachershowsthenewwordsonPPT.Askstudentstotrytoreadthesewords.Thestudentsfollowtheteacherthreetimes.Thengivethestudentsfiveminutestorememberthewords.Letstudentsspellandreadthemonebyone.設(shè)計(jì)意圖:教師以PPT的形式呈現(xiàn)本課中出現(xiàn)的生詞,領(lǐng)著學(xué)生們朗讀并記憶,為下面的課文學(xué)習(xí)做好充分準(zhǔn)備.Ⅲ．Reading1．Readthetextaloud.T:Boysandgirls,it'sourreadingtime.Pleasereadafterthevideoandyoushouldpaymoreattentiontoyourpronunciation.設(shè)計(jì)意圖:讓學(xué)生大聲朗讀課文,對(duì)課文的意思有個(gè)大致的了解,對(duì)于培養(yǎng)學(xué)生的正確發(fā)音以及培養(yǎng)學(xué)生的語感都有重要作用.2．Carefulreading.T:Boysandgirls,nowthistime,I'llmaketheexercisealittlemoredifficult.Readthelessonagainandanswerthequestions.ShowLet'sDoIt!Readthelessonandanswerthequestions.（1）Whatisablueprint?（2）Whichismorecomplex,buildingalivingthingorbuildingahouse?（3）DosometwinshavethesameDNA?（4）IsitpossibletochangeyourDNA?（5）WhoseDNAisrelatedtoyours?Keys:（1）Ablueprintisadrawingthatshowshowtoputahousetogetherwithmanydifferentparts.（2）Buildingalivingthingisfarmorecomplexthanbuildingahouse.（3）Yes,theydo.（4）Yes,itis.Inthefuture,scientistsmightbeabletochangeourDNA.（5）Peoplewhoarerelatedtome.Forexample,myparentsandgrandparents.設(shè)計(jì)意圖:要求學(xué)生認(rèn)真閱讀課文,把握課文信息,回答問題,對(duì)文章內(nèi)容有更深層次的理解.3．Readthetextandfindoutmainphrasesandsentences.Mainphrases:IngeneralExceptforBerelatedtoBillionsofMainsentences:WhatcanscientistsdowithDNA?Butbuildingalivingthingisfarmorecomplexthanbuildingahouse.Exceptforsometwins,everylivingthinghasitsownuniqueDNA.SomehealthproblemscanbecausedbyproblemsinyourDNA.Inthefuture,scientistsmightbeabletochangeyourDNA.TherearecopiesofyourDNAineverypartofyourbody.YouhaveyourownuniqueDNA,butitrepeatspatternsfromyourparents'DNA.YourDNAhasbillionsofinstructionsthatexplainwhyyouarethewayyouare.It'soneofthemostamazingthingsontheearth!教材解讀:（1）WhatcanscientistsdowithDNA?dowith為固定短語,意為"處理",強(qiáng)調(diào)對(duì)象拓展:dealwith也意為"對(duì)待,處理",側(cè)重處理的方式（2）Ingeneral,ablueprintisadrawingthatshowshowtoputahousetogetherwithmanydifferentparts.ingeneral意為different為形容詞,意為bedifferentin…在……上不同.（3）Butbuildingalivingthingisfarmorecomplexthanbuildingahouse.,與疑問詞what連用.、方法,與疑問詞how連用."一般而言,概括說來",通常置于句首,也可以用generallyspeaking來表示."不同的",常用于以下結(jié)構(gòu)中:bedifferentfrom與……不同;living為形容詞far為副詞,意為"非常,遠(yuǎn)遠(yuǎn):同樣用法的詞還有even"甚至lot"……得多"等等（4）Exceptforsometwins,everylivingthinghasitsownuniqueDNA.exceptfor意為"除……之外",它要求排除的是不同類的:exceptfor,except,besides,butexceptfor意為"除了",表示對(duì)主體的肯定和局部的否定except可用作介詞,意為"除了……之外",表示同類事物間的排除關(guān)系besides可用作介詞,意為"除……之外",表示同類事物間的疊加關(guān)系but可用作介詞,意為"除……之外",常與no,all,every,each,none,nobody等詞連用與except互換every為形容詞,意為"作主語時(shí),謂語動(dòng)詞用單數(shù);every強(qiáng)調(diào)整體概念,不能直接與拓展:each可作形容詞,意為"每個(gè)的",也可用作代詞語,其后接單數(shù)名詞;"each+單數(shù)名詞"或each作主語時(shí),謂語動(dòng)詞用單數(shù)each強(qiáng)調(diào)個(gè)體,可與of連用,指兩者及兩者以上中的每一個(gè)注意:"every/each+單數(shù)名詞+and+every/each+單數(shù)名詞"結(jié)構(gòu)作主語時(shí)式.own作形容詞,意為",用來修飾形容詞和副詞的比較級(jí)";rather"相當(dāng)";much"……得多"活著的,活的",常作定語.,表示程度.拓展";alittle/bit"有點(diǎn)";a..辨析,用于不同類的事物間...,有時(shí)可."每一的,每一個(gè)的of連用,意為",其后接單數(shù)名詞;"every+單數(shù)名詞,指三者及三者以上中的每一個(gè)"每個(gè)",each作形容詞時(shí)只能作定.;.,謂語動(dòng)詞用單數(shù)形,意為"自己的",位于物主代詞或名詞所有格之后,還可作動(dòng)詞,意為"擁有",其,其名詞形式為owner,意為"物主（5）SomehealthproblemscanbecausedbyproblemsinyourDNA.health為不可數(shù)名詞,意為"健康",常構(gòu)成短語ingood/badhealth,意為后賓語多表示房屋、土地或財(cái)產(chǎn)等"."健康/不健康".拓展:healthy為形容詞,意為"健康的";unhealthy意為"不健康的",keep/stayhealthy意為"保持健康".healthily為副詞cause為及物動(dòng)詞,意為語.拓展:cause作名詞用.,意為"健康地",eathealthily意為"吃得健康".,也可接動(dòng)詞不定式作賓語補(bǔ)足"引起,導(dǎo)致,發(fā)生",后面可接雙賓語,意為"原因、起因".指導(dǎo)致某種結(jié)果、造成一種事實(shí)的原因,通常與of連（6）Inthefuture,scientistsmightbeabletochangeyourDNA.beableto意為"能,會(huì)",表示通過努力而獲得的能力,強(qiáng)調(diào)結(jié)果,可用于各種時(shí)態(tài),其后接動(dòng)詞原形.（7）YouhaveyourownuniqueDNA,butitrepeatspatternsfromyourparents'DNA.repeat為及物動(dòng)詞,意為"重復(fù),重述",后接名詞或代詞作賓語.parents'意為"父母親的",是復(fù)數(shù)名詞的所有格形式.（8）FromyourDNA,scientistscanidentifynotonlyyou,butalsopeoplewhoarerelatedtoyou.identify為及物動(dòng)詞,意為"確認(rèn),識(shí)別,鑒別",后接名詞或代詞作賓語.berelatedto意為"和……有聯(lián)系,和……有關(guān),與……有親戚關(guān)系".related為形容詞,意為"有關(guān)的、相關(guān)的".relate為動(dòng)詞,意為"把……聯(lián)系起來",常與to或with搭配.（9）YourDNAhasbillionsofinstructionsthatexplainwhyyouarethewayyouare.本句句末的youare是theway的定語從句.theway的定語從句的引導(dǎo)詞可用inwhich,或用that,也可以不用引導(dǎo)詞.way在本句中意為"情況、狀態(tài)".（10）It'soneofthemostamazingthingsontheearth!oneofthemostamazingthings意為"最令人驚奇的事情之一",為"oneofthe+形容詞的最高級(jí)+復(fù)數(shù)名詞"結(jié)構(gòu).其中定冠詞the也可使用形容詞性的物主代詞來代替.設(shè)計(jì)意圖:學(xué)生是學(xué)習(xí)的主體,教師要努力調(diào)動(dòng)學(xué)生學(xué)習(xí)的積極性和主動(dòng)性,通過組內(nèi)合作討論、探究,找出課文中的關(guān)鍵單詞、短語和句子,把所學(xué)的知識(shí)轉(zhuǎn)化為學(xué)習(xí)能力.Ⅳ．Task1．ShowLet'sDoIt!IsitagoodideatochangetheDNAofthefoodweeat?Somepeoplesaydoingthismakesourfoodbetter.Othersthinkit'stoodangerous.SearchtheInternetforinformationandwritedownyourideas.2．HavethestudentsconsiderthequestionsinLet'sDoIt!No.4.3．Havethemcompletethistaskandresearchgeneticallymodifiedfood.Theirresearchshouldanswerthefollowingquestions:Doyouthinkit'sagoodideatochangetheDNAofthefoodweeat?Whyorwhynot?Whataresomeofthepositivesofgeneticallymodifiedfood?Whataresomeofthenegativesofgeneticallymodifiedfood?4．Havethegroupspresenttheirresearchintheformofacommercialthatiseitheradvertisingthecontinuationofgeneticallymodifiedfoodortheendofit.:鍛煉學(xué)生的口語表達(dá)與寫作能力,同時(shí)培養(yǎng)學(xué)生的合作意識(shí)設(shè)計(jì)意圖.Ⅴ．Practice1．ShowLet'sDoIt!No.2.Fillintheblankswiththephrasesinthebox.ingeneral,exceptfor,notonly…butalso,relatedto,evenif,thesame…as…（1）Yourhomeworkisquitegood______afewspellingmistakes.（2）______theyoung______theoldlikepopmusic.（3）Kate'shairis______color______hersister's.（4）______,womenlivelongerthanmen.（5）______manydifficultiesremain,wecanovercomethem.（6）Iswealth______happiness?2．Completethepassagewiththesentencesinthebox.ChangingDNADoyouknowDNAcanbechanged?Haveyoueverseenapigwithadog'sbody?Ofcoursenot!Pigsanddogscan'thavebabiestogether.______butnow,scientistscandoit.ScientistscantakeDNAfromonekindofanimalandputitintoanotherkindofanimal.TheycandesignnewplantsbycombiningtheDNAofotherplants.______Somescientistsareworried.TheysayweneedtoknowmoreaboutDNAbeforewestartchangingit.______Butwhatiftheplantsarebadforhumans,too?A．TheirDNAcan'tcombine.