选修八第二单元ppt课件 Cloning.ppt

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1、cloning,Unit2,Learning aims:* To have a good understanding of the reading passage;* To be able to discuss some of the issues associated with cloning.,Dolly the sheep,Dolly was cloned while the others were born naturally.,How does Dolly differ from other sheep?,man-made clone,Natural clone is one tha

2、t occurs in a natural form of cloning without human help.,Man-made clone is one that is produced through human intervention(介入) .,Look at the following pictures and discuss which ones are natural clones and which ones are man-made clones.,Discussion,Natural or man-made clones?,一株草莓依靠它沿地“爬走”的匍匐茎,一年内就

3、能长出数百株草莓苗。,Natural clone,A strawberry plant,Growing new plants,man-made clone,Natural clone,Twins,Do you want to know:What is a clone?How is a clone is produced?What benefits can human gain from cloning?What problems may arise when humans are cloned?,Reading:,cloning:where is it leading us?,1. Scan

4、the following passage and match the paragraph with the correct sentence.,Para 1 A.The problems of DollyPara 2 B.The two major uses and procedures of cloningPara 3 C.The impact of cloning DollyPara 4 D.The definition of cloningPara 5 E. Peoples reaction to cloning,Fast-reading (5 minutes),2. The main

5、 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 so it must be forbidden. C. Animal cloning is well developed because Dolly the sheep was born. D. Animal cloning raised arguments and scientists are not sure about i

6、ts future.,Fast-reading,Careful-reading,Task1: （para1-2) (3 minutes)1. What is cloning? 2.What are the two major uses of cloning? 3. Why is it easier to make commercial plant clones than animal clones?,Careful-reading,Task1: （para1-2)What is cloning? Cloning is a way of making an exact copy of anoth

7、er animal or plant.,Careful-reading,Task1: （para1-2)2. What are the two major uses of cloning? The first use is to produce commercial quantities of plants. The second is to research on new plants species and do medical research on animals.,Careful-reading,Task1: （para1-2)3. Why is it easier to make

8、commercial plant clones than animal clones? Because cloning plants is straightforward while cloning animals is very complicated.,Careful-reading,Task2: （para3-5) (4minutes)1. It can be inferred from the passage that a cloned animal_. usually lives as long as the original oneB. usually lives longer t

9、han the original oneC. usually lives shorter than the original oneD. is usually as healthy as the original one,推理判断题,2. Which of the following is not an advantage of cloning?Cloning can be used for medical purposes. Large quantities of food can be produced by cloning.Cloning can help keep animals fr

10、om becoming extinct.Famous persons who have passed away can be cloned.,3. Whats the writers attitude towards cloning? A. Supportive B. Neutral C. Negative D. Subjective,中立的,objective 客观的，公正的,Detailed-readingTask1: Group work1 (3minutes)Discuss in groups and then show us the procedure of the cloning

11、of Dolly the sheep.,克隆羊多莉的产生过程（动画）.swf,The procedure of cloning Dolly the sheep:,First, female sheep A provides _, whose nucleus is removed. Female sheep B provides a _ cell, whose nucleus contains all the genes needed to produce a new sheep. Then the nucleus from sheep B and the egg cell from sheep

12、 A are joined using _. The cell divides and grows into an _, which is put into female sheep C. So she becomes the carrier of the clone. Finally, a new lamb, which is the clone of sheep B, is produced.,an egg cell,somatic,electricity,embryo,Detailed-readingTask 2: Fill in the chart using the informat

13、ion from the reading passage. (4minutes),Answers:,1. Animal clones may develop the _ of older animals.,2. Animal clones may die _ than the donor animals.,1. Medical cloning could be used to _ serious illnesses in humans.,2. Gardeners can use cloning to produce _ qualities plants.,illnesses,cure,youn

14、ger,commercial,Answers:,3. _ leaders may want to clone themselves.,4.There are _ questions of cloning human beings.,3. Cloning is valuable for research on _.,4. Cloning is valuable for _ on animals.,Evil,new plant species,moral,medical research,Challenge yourself: (3minutes),阅读下面材料，在空白处填入适当的内容（不多于3个

15、词）或括号内单词的正确形式。 Cloning is a way of making _ exact copy of another animal or plant. Cloning plants is straight-forward _ cloning animals is complicated. Cloning animals is a difficult task _ (undertake). But at last the determination and patience of scientists _ (pay off) in 1996 with a breakthrought

16、he cloning of Dolly the sheep. The fact _ Dolly seemed to develop normally was very encouraging. Then came the disturbing news that she had become seriously ill. Cloning scientists _ (cast down) to find that Dollys illnesses,an,while,to undertake,paid off,that,were cast down,Challenge yourself:,were

17、 more appropriate to a much _(old) animal. Altogether Dolly lived six and a half years. Dollys appearance raised a storm of _ (object) and had a great impact _ the media and public imagination. It became controversial. Some governments began to reform their legal systems and forbade research into hu

18、man cloning, but other countries continued to accumulate evidence of the abundant medical aid _ cloning could provide.,older,objections,on,that/which,Show yourself:Group work2:A Press Conference about cloning,A Press Conference about cloningWork in groups of six. One student acts as the host, anothe

19、r student acts as the cloning scientist and the other students are the journalists, and the journalists can ask any questions about cloning.,克隆羊多莉的产生过程（动画）.swf,Homework:1. Read the passage again and underline the sentences in the text containing the appositive phrases（同位语）or appositive clauses（同位语从句）.Write a short passage with the title “My opinions on cloning.” First , you state the advantages and disadvantages of cloning. At the end of your passage, you can add your own opinion.,