选修八 2.4Unit 2　Reading.ppt

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1、新课标人教版课件系列,高中英语选修(模块）8-2.4,Reading,In pairs,look at these pictures and discuss which ones are natural clones and which ones are man-made.Explain how they differ.,Warming up,一株草莓依靠它沿地“爬走”的匍匐茎,一年内就能长出数百株草莓苗,富贵竹插枝即活,仙人掌每块落地就生根,Dolly是世界上第一例用体细胞乳腺上皮细胞,通过细胞核移植技术,在复杂的人工操作下,得到的一只小绵羊。,多利,我国成功繁殖克隆兔 体形要比普通兔大许多

2、,第一只克隆宠物猫,克隆马及其“母亲兼姐姐”,克隆的荧光小猪(左)和正常小猪(右),克隆,是Clone的译音,意为生物体通过细胞进行的无性繁殖形成的基因型完全相同的后代个体组成的种群,简称为无性繁殖。克隆一词于1903年被引入园艺学,以后逐渐应用于植物学、动物学和医学等方面。但克隆与无性繁殖是不同的。无性繁殖是指不经过雌雄两性生殖细胞的结合、只由,一个生物体产生后代的生殖方式,常见的有孢子生殖、出芽生殖和分裂生殖。由植物的根、茎、叶等经过压条或嫁接等方式产生新个体也叫无性繁殖。绵羊、猴子和牛等动物没有人工操作是不能进行无性繁殖的。科学家把人工遗传操作动物繁殖的过程叫克隆,这门生物技术叫克隆技术

3、。,克隆的基本过程是先将含有遗传物质的供体细胞的核移植到去除了细胞核的卵细胞中,利用微电流刺激等使两者融合为一体,然后促使这一新细胞分裂繁殖发育成胚胎,当胚胎发育到一定程度后,再被植入动物子宫中使动物怀孕,便可产下与提供细胞者基因相同的动物。,这一过程中如果对供体细胞进行基因改造,那么无性繁殖的动物后代基因就会发生相同的变化。,In pairs discuss what you understand about clothing.Then list the questions you want to find out.Share your lists with one another.,Pre

4、-reading,Questions about cloning,1.What is a clone?,A clone is group of cells or organisms that are genetically identical and have been produced asexually from the same original cell.They include natural and man-made clones.,2.How is a clone produced?,The cloning of plants is simple and relatively e

5、asy.It can be done by taking cuttings(man-made cloning)or letting the plant produce its own runners(natural cloning).The cloning of animals is more complicated.It was not achieved until 1996 and is fully explained in the first reading.,3.What benefits can humans gain from cloning?,1)Medical cloning

6、can help cure serious illnesses that ruin ones quality of life(such as Parkinsons disease or Alzheimers disease).2)It can help infertile people have babies.,4.What problems may arise when humans are cloned?,1)People may want to clone themselves so they can live forever.2)People may want to clone dea

7、d children.3)People may want to clone their favorite pets.,Reading,Please read the reading to get main idea,and then in groups,finish the following exercises.,1.The main idea of the text is_ A.animal cloning is very valuable and can benefit the world.B.animal cloning could be misused by bad people s

8、o it must be forbidden,主旨大意,C.animal cloning is well developed because Dolly the sheep was born.D.animal cloning raised arguments and scientists are not sure about its future.,2.Which of the following statements about cloning is NOT true according to text?_ A.Cloning is something that has been devel

9、oped quite recently.B.Twins that look exactly the same are originally from the same egg.,细枝末节,C.Cloning is used by gardeners to make more money.D.Animal cloning is much more difficult than plant cloning.,A,3.The cloning of Dolly the sheep succeeded because_.A.its easier to clone a sheep than other a

10、nimals B.the scientists were determined and worked hard with patience,C.the scientists were rewarded and got lots of moneyD.many other attempts to clone mammals failed,B,4.The lamb is the clone of the cell from sheep because_.A.it provides the egg cell B.it gives birth to the lamb C.it provides the

11、nucleus D.it is a female sheep,5.The sheep that donated the somatic cell most probably lived _ years.A.3 B.6 C.9 D.12,推理判断,Do you know about:,The procedure works of a sheep?,克隆羊诞生图示,“多利”的诞生标志着克隆研究取得新的进展和重大突破,而且这个结果证明:动物体中执行特殊功能,具有特定形态的所谓高度分化的细胞与受精卵一样具有发育成完整个体的潜在能力。也就是说,动物细胞与植物细胞一样,也具有全能性.,“多利”的诞生有什么

12、重大的意义和影响？,1.It suddenly opened everybodys eyes to the possibility of using cloning to cure serious illnesses,and even producing human beings.突然每个人都看到了利用克隆技术治愈重病,甚至制造人的可能性。,长句难句:,of using cloning to cure serious illnesses,and even producing human beings作定语,其中using和producing是并列关系。,2.Newspapers told st

13、ories of evil leaders hoping to clone themselves and religious leaders raises moral questions.报纸报道了不良领导人希望克隆自己的消息,宗教领袖提出了道德方面的质疑。,由and 连接了两个并列分句,前句中hoping to clone themselves作宾补。句中stories意为“消息”。,例句观察(课文原句)The fact is that they are natural clones of each other.（作表语）The fact that she seemed to develop

14、 normally was very encouraging.（作同位语）,语法专攻:,Then came the disturbing news that Dolly had become seriously ill.（作同位语）However,scientists still wonder whether cloning will help or harm us and where it is leading us.（作宾语）,Cloning people is a good thing,or a bad thing?克隆人是福音,还是恶兆？,Thinking,意大利狂人医生:安蒂诺里,冒

15、死也要克隆人的科学家:布瓦瑟利耶,1.克隆技术现在还不成熟,克隆人可能有很多先天性生理缺陷。2.克隆人的身份难以认定,他们与被克隆者之间的关系无法纳入现有的伦理体系。,反对克隆人,3.克隆技术有可能被滥用,成为恐怖分子的工具。4.从生物多样性上来说,大量基因结构完全相同的克隆人,可能诱发新型疾病的广泛传播,对人类的生存不利。,1.“不让我们克隆人,就是不让我们修正我们的错误,人类 历史难道能够这样构造吗？”纽约时报书评2.“当然应该克隆人,如果谁第一个掌握了这个技术,他就是我真正的、也是唯一的竞争对手。”比尔盖茨,支持克隆人,3.“克隆人绝对是科学上了不起的进步,克隆技术必将创造21世纪的辉煌。”麻省理工学院生命工程教授约翰布洛克4.“人体商业化是人类经济活动中无与伦比的成就,毫无疑问,克隆技术的出现将为世人创造一个最为广泛和深远的市场。”英国经济学家杂志。,Homework,Finish off Ex.1,2,3,Page12.,