Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Unit 2 Cloning the important events in cloning history In 5000B.C. ( 谷物选种) Human Beings began to choose the best seeds from some kinds of crops. That was the beginning of controlling life according to human’s will. In 1952: Cloning tadpole ( 克隆蝌蚪) The American scientists created a copy of tadpole by means of using a tadpole cell. This tiny tadpole has become the first kind of cloning animal. • In 1978: The first case of tube infant (试管婴儿 ) appeared. ☆A British doctor used the sperm(精液)of a man and fertilized(受精 ) it in a test tube(试管). ☆Then transplanted(移植) the embryo(胚胎) into the womb(子宫 ) of a healthy mother. ☆The first tube infant called Louis appeared. In 1996, the famous sheep “Dolley” was cloned successfully Dolley and the Father of Dolley – Ianwilmut ( 伊恩.威尔 姆) • In 1998 A series of things were cloned. • The scientists in Hawaii University cloned over 50 mice. • Some private institutions ( 协会 ) successfully cloned little oxen. In 2002, the scientists of A&M University in USA has bred the first cloned cat in the world. Nowadays : ☆ Cloned dog, mouse, rabbit, goat, ox, pig appeared . ☆ China become the seventh country that has the ability to clone pigs. ☆ China has succeeded in using embryonic(胚胎的) cell to clone many animals. the important events in cloning history Warming up ( 4ms ) Answer the following questions: 1. Do you like dinosaurs? Where have you seen them? Can you see them in our real life? Why? 2. Do you think it is possible to clone dinosaurs? If yes, do you think that’s good for human beings? Why? ( Students give their own answers.) Reading -- I scanning ( 5ms ) Read the text, then tell the following sentences are true or false. ( Students can discuss in pairs. ) 1. Scientists are still experimenting with cloning mammals because they think it can make money. F 2. The animals that have disappeared from the earth, like dinosaurs, can be brought back to life through cloning. F 3. If we can clone any extinct animals, we should let them live in a zoo. F Reading -- II Detail reading ( 6ms ) Read the text, then answer the following questions. ( Students can discuss in pairs. ) 1. Why should’t you clone an extinct animal unless there is enough diversity in the group? 2. Why is it wrong to clone an extinct animal if it would have to live in a zoo? 3. Why can’t you clone the DNA of animals that have been extinct longer than 10,000 years? 1. Why should’t you clone an extinct animal unless there is enough diversity in the group? There will not be enough genetic variation in the group 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 environment for a wild animal. 3. Why can’t 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 can’t survive so long. Reading -- III Argument ( 10ms ) 1. Read the passage again and have a argument according to the requirement of Ex.2 on Page 16. 2. Students work in groups, when discussing, the head of each group should write down the opinions of all the members. 3. Ask some volunteers to show their opinions.