高中英语 Unit2 Cloning Period4课件1 新人教版选修8.ppt

1、Extensive reading,The return of the dinosaurs ?,克隆技术大事记,1938年:德国科学家首次提出克隆想法。 1952年:科学家开始用青蛙进行克隆实验。 1970年:克隆青蛙实验取得突破,青蛙卵发育 成了蝌蚪, 但是在开始进食以后死亡。,1981年:科学家进行克隆鼠实验,据称用鼠 胚胎细胞培育出了正常的鼠。 1984年:第一只胚胎克隆羊诞生。 1997年2月24日:英国罗斯林研究所宣布克 隆羊培育成功。科学家用取自一只 6岁成年羊的乳腺细胞培育成功一 只克隆羊。,1998年2月23日:英国PPL医疗公司宣布,该公司克隆出一头牛犊“杰弗逊先生”。 19

2、98年7月5日:日本科学家宣布,他们利用成年动物体细胞克隆的两头牛犊诞生。,1998年7月22日:科学家采用一种新克隆技术,用成年鼠的体细胞成功地培育出了第三代共50多只克隆鼠,这是人类第一次用克隆动物克隆出克隆动物。 1999年5月31日:美国夏威夷大学的科学家,利用成年体细胞克隆出第一只雄性老鼠。,1999年6月17日:以美藉华人科学家杨向中为首的研究小组利用一头13岁高龄的母牛耳朵上取出的细胞克隆出小牛。 2000年1月3日:美国著名华人杨向中,用体外长期培养后的公牛耳皮细胞成功克隆出6头牛犊。,2000年1月:美国科学家宣布克隆猴成功,这只恒河猴被命名“泰特拉”。 2000年3月14日

3、:曾参与克隆小羊“多利”的英国PPL公司宣布,他们成功培育出5头克隆猪。,Please enjoy some pictures about dinosaurs.,霸王龙tyrannosaurus,剑龙stegosaurs,角龙 ceratopsids,雷龙 brontosaurus,翼龙pterodactyl,Answer the following questions:,1. Why shouldnt you clone an extinct animal if there isnt enough diversity in the group? 2.Why is it wrong to cl

4、one an extinct animal if it would have to live in a zoo? 3.Why cant you clone the DNA of animals that have been extinct longer than 10,000 years?,Reading,1. Why shouldnt you clone an extinct animal if there isnt enough diversity in the group?,Keys:,There will not be enough genetic variation in the g

5、roup to be able to resist new illnesses.,2. Why is it wrong to clone an extinct animal if it would have to live in a zoo?,It is not a good idea to clone an animal that would have to live in a zoo because it is not a suitable habitat to develop and increase its numbers. The zoo is not a natural envir

6、onment for a wild animal.,3. Why cant you clone the DNA of animals that have been extinct longer than 10,000 years?,The DNA of animals more than 10,000 years old is not suitable for cloning, for it cant survive so long.,The writer of the text_ A. is excited by the possibility of cloning fierce and e

7、xtinct animals B. believes that extinct animals can be brought back to life by cloning C. thinks it impossible or unsuitable to clone extinct animals like dinosaurs D. dreams of dinosaurs returning to the earth,主旨大意,2. The film Jurassic Park is popular because _. A. people are interested in the subj

8、ect of cloning B. all the actors are dinosaurs C. it was directed by a scientist who clones dinosaurs D. it proves very interesting,细枝末节,A,3. Which of the following is true? _ Mice were cloned in 1981. B. Dolly the sheep was the first cloned animal. C. The name of the cloned cow is “Bison” D. China

9、was successful in cloning mammals.,4. The reasons why a group of cloned animals all die of the same illness do NOT include_. A. they have the same arrangement of genes B. there isnt enough diversity in the group for it to overcome illnesses C. the illness is a new one D. their arrangement of genes c

10、an not resist that new disease,5. We can infer from the text that_ A. scientists are experimenting to clone dinosaurs B. dinosaurs will never return to the earth C. cloned animals will only live in the zoo D. the DNA of dinosaurs can only survive 10,000 year,推理判断,True or false.,Scientists are still

11、experimenting with cloning mammals because they think it can make money. The animals that have disappeared from the earth, like dinosaurs, can be brought back to life through cloning. If we can clone any extinct animals, we should let them live in a zoo.,F,F,F,1. The popularity of the film Jurassic

12、Park, in which a scientist clones several different kinds of extinct dinosaurs, proves how interested ordinary people are in the subject.,长句难句,电影侏罗纪公园的欢迎证实了普通人对这一话题是多么感兴趣,在该电影中一位科学家克隆了几种不同的恐龙。 in which引导定语从句, how引导宾语从句。,2. From time to time people suggest that the animals that have disappeared from

13、the earth, like dinosaurs, can possibly be brought back to life through cloning. 人们时常设想从地球上消失的动物,例如恐 龙,有可能通过克隆技术使它们复活。,from time to time有时, 间或, 偶尔, = occasionally, now and then。,3. It is useless to clone an animal if there is not enough diversity in the group for it to overcome illnesses. 该群中如果没有足够的

14、多样性使它克服疾 病,克隆动物就没有用。,当动词不定式、动名词或从句作主语时, 通常把它们放在谓语之后, 而用it作句子的形式主语。,4. Diversity in a group means having animals with their genes arranged in different ways. 群中的多样性指的是拥有 基因排列方式不同的动物。 with their genes arranged in different ways 作定语, in different ways 以不同的方式。,5. .but others will survive and pass on the

15、 ability to resist that disease to their children. .其他的将存活下来并传递给其后代抵抗 这种病的能力。,resist 作及物动词主要有三个义项: 抵抗, 对抗; 抵挡, 防止; (与cannot, could not连用) 无法抗拒, 无法抵挡。,base on/upon 以为基础, 依据 其结构为: base sth. on/upon sth. is based on/upon,6. Based on what we know now, you can not clone animals that have been extinct lon

16、ger than 10000 years.据我们现在所知, 绝种一万年以上的动物不能克隆。,May the best animal win! Which extinct animals are worth restoring by means of cloning? Choose one and use the information to help you argue why this animal should be restored to the earth.,Discussion,Great Auk (1844),Auroch (1627),Dodo bird (1755),Quagg

17、a (1883),A sample dialogue (P16),S1: I think the dodo bird should be returned to the earth. It hasnt been extinct very long. So its DNA will still be good enough for cloning. S2: Yes and sailors in the past always described the dodo as being a very friendly animal. So it would make a good pet. It wa

18、snt too large either.,I cant see any other extinct animals becoming a pet, can you? S1: No, indeed. 1 know its a bird like the Great Auk but neither of them could fly. So if you kept either, it wouldnt escape from a park, a family or its home in the wild. You could also farm a dodo, unlike all the o

19、thers, and produce many of them as exotic pets.,S2: And what about its large nutritious eggs? Just one would feed a large family. So theres more than one reason for producing it in commercial numbers. S1: Did you know that its meat is very tasty too! Perhaps it could be farmed like ostriches and pro

20、vide a good source of protein.,S2: The only problem is that it needs hot climate to survive. But thats easy to provide with all its other advantages. I dont think any of the other animals stands a chance against the dodo. S1: So we both agree that the best extinct animal to be cloned is the dodo bird. S2: Yes.,3. A sample report(p.17),The dodo is the most suitable animal to be cloned for severa