Transcript Unit 3
Unit 3 Science and nature Warm up Do you think that human beings should try to control nature? Should we do anything against the laws of nature? Why or why not? What do you know about clones? A clone is an animal or a plant copied from the cell of another animal or plant. The two animals or plants are exactly the same. What has already been cloned by scientists? the world’s most famous sheep Dolly (5 Jul. 1996 – 14 Feb. 2003) Dolly was the first cloned mammal created by a Scottish scientist and his group in 1996. Dolly was world famous because she was exactly the same as her mother, in appearance and in genes. Dr. Ian Wilmut and Dolly We are cloned female pigs and we were born on Christmas Day 2001. I was created using a cell from an adult cat. I am the first cloned monkey. I was born at a research centre in the USA What is cloning? Cloning is a way of making an exact copy of another animal or plant. It includes natural cloning and manmade cloning. How is a clone produced? The cloning of plants is simple and relatively easy. 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. Do you think the cloned animals are as healthy as the natural ones? Dolly is, but scientists do not yet know whether this is the exception or the rule. Some early evidences suggest that clones may have health problems and that they may age prematurely (早衰的，未老先 衰). Loot at the textbook. There are some pictures and they show the cloning animals in the world. Do you think it would be a good idea to clone humans some day? Why or why not? What benefits can humans gain from cloning? Medical cloning can help cure serious illnesses that ruin one’s quality of life. It can help infertile people have babies. What problems may arise when humans are cloned? People may want to clone themselves so they can live forever. People may want to clone dead children. People may want to clone their favourite pets. What do you think of human cloning? Do you think governments should pass laws to prohibit human cloning? Why or why not? Party A They shouldn’t, for… reasons: 1. Cloning can help cure many diseases and save a lot of people’s lives. 2. … 3. … Party B They should, for… reasons: 1. Cloning can lead to ethical (伦理) problems. 2. … 3. … Giving an oral report Today our class had a discussion about whether the governments should pass laws to prohibit human cloning. Some students think that the governments should, for… However, some other students think it necessary to prohibit…, for… In my opinion, …