选修八第二单元ppt课件-Cloning.ppt

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1、Unit2Learning aims:* To have a good understanding of the reading passage;* To be able to discuss some of the issues associated with cloning.Dolly the sheepDolly was cloned while the others were born naturally.How does Dolly differ from other sheep?Natural clone is one that occurs in a natural form o

2、f cloning without human help. Man-made clone is one that is produced through human intervention(介入介入) .Look at the following pictures and discuss which ones are natural clones and which ones are man-made clones. DiscussionNatural or man-made clones? 一株草莓依靠它沿地一株草莓依靠它沿地“爬走爬走”的匍匐茎的匍匐茎,一一年内就能长出数百株草莓苗年内就

3、能长出数百株草莓苗。A strawberry plantGrowing new plantsTwinsDo you want to know:1.What is a clone?2.How is a clone is produced?3.What benefits can human gain from cloning?4.What problems may arise when humans are cloned? Reading:1. Scan the following passage and match the paragraph with the correct sentence.

4、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 cloningFast-reading (5 minutes)2. The main idea of the text is _. A. Animal cloning is very valuable and can benefit

5、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 its future.Fast-readingCareful-readingTask1: （para1-2) (3 minutes)1. What is

6、 cloning? 2.What are the two major uses of cloning? 3. Why is it easier to make commercial plant clones than animal clones? Careful-readingTask1: （para1-2)1.What is cloning? Cloning is a way of making an exact copy of another animal or plant. Careful-readingTask1: （para1-2)2. What are the two major

7、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-readingTask1: （para1-2)3. Why is it easier to make commercial plant clones than animal clones? Because cloning plants is straightfo

8、rward while cloning animals is very complicated. Careful-readingTask2: （para3-5) (4minutes)1. It can be inferred from the passage that a cloned animal_.A. usually lives as long as the original oneB. usually lives longer than the original oneC. usually lives shorter than the original oneD. is usually

9、 as healthy as the original one推理判断题推理判断题2. Which of the following is not an advantage of cloning?A. Cloning can be used for medical purposes. B. Large quantities of food can be produced by cloning.C. Cloning can help keep animals from becoming extinct.D. Famous persons who have passed away can be c

10、loned.3. Whats the writers attitude towards cloning? A. Supportive B. Neutral C. Negative D. Subjective中立的中立的 objective 客观的，客观的，公正的公正的Detailed-readingTask1: Group work1 (3minutes)Discuss in groups and then show us the procedure of the cloning of Dolly the sheep.克隆羊多莉的产生过程（动画）克隆羊多莉的产生过程（动画）.swf.swfTh

11、e 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 A are joined using _. The cell divides a

12、nd 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 cellsomaticelectricityembryoDetailed-readingTask 2: Fill in the chart using the information from the reading passage. (4minutes)Proble

13、ms or dangers of cloningAdvantages of cloning1. Animal clones may develop the _ of older animals.1. Medical cloning could be used to _ serious illnesses in humans.2. Animal clones may die _ than the donor animals.2. Gardeners can use cloning to produce _ qualities plants.3. _ leaders may want to clo

14、ne themselves.3. Cloning is valuable for research on _.4.There are _ questions of cloning human beings.4. Cloning is valuable for _ on animals.Answers:Problems or dangers of cloningAdvantages of cloning1. Animal clones may develop the _ of older animals.2. Animal clones may die _ than the donor anim

15、als.1. Medical cloning could be used to _ serious illnesses in humans.2. Gardeners can use cloning to produce _ qualities plants.illnesses cureyoungercommercialAnswers:Problems or dangers of cloningAdvantages of cloning3. _ leaders may want to clone themselves.4.There are _ questions of cloning huma

16、n beings.3. Cloning is valuable for research on _.4. Cloning is valuable for _ on animals.Evilnew plant speciesmoralmedical researchChallenge yourself: (3minutes)阅读下面材料，在空白处填入适当的内容（不多于阅读下面材料，在空白处填入适当的内容（不多于3 3个词）或括号内单词的正个词）或括号内单词的正确形式。确形式。 Cloning is a way of making _ exact copy of another animal or

17、 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 breakthroughthe cloning of Dolly the sheep. The fact _ Dolly seemed to develop normally

18、was very encouraging. Then came the disturbing news that she had become seriously ill. Cloning scientists _ (cast down) to find that Dollys illnessesanwhileto undertakepaid offthatwere cast downChallenge yourself:were more appropriate to a much _(old) animal. Altogether Dolly lived six and a half ye

19、ars. 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 human cloning, but other countries continued to accumulate evidence of the abundant m

20、edical aid _ cloning could provide.olderobjectionsonthat/whichShow yourself:Group work2:A Press Conference about cloningA Press Conference about cloningWork in groups of six. One student acts as the host, another student acts as the cloning scientist and the other students are the journalists, and t

21、he 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）（同位语）or appositive clauses（同位（同位语从句）语从句）.2.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.