Step I Lead-in (Warming Up)

This topic is difficult for students. So the teacher should help the students learn more about it. Do this in the way of asking and answering questions.

T: Do you enjoy watching TV series? Have you ever seen Journey To The West? It tells how Tang monk went to the Western Heaven to acquire scriptures. In this series, Monkey King plays an important part. He has seventy-two transformations. He can copy another one which looks exactly like him, which helps him overcome lots of difficulties on the way to the Western Heaven. But nowadays, you can imagine how rapidly the modern science and technology develop. I think most of you must know something about space traveling. Human beings can do what monkey King could do or even could not do. In recent years, a hot topic, cloning is often mentioned, especially when the cloning Dolly the sheep appeared. Cloning technologies have been around for much longer than Dolly, though. First things first, what is cloning and a clone? It sounds very different and complicated to us. In fact, I mean, in our daily life, this happens often. For example, gardeners take cuttings from growing plants to make new ones. You often see that your mother picks a small branch from a growing plant to make a new one. If she likes this kind of flowers, she can do cloning. Cloning also happens in animals or human beings when twins identical in sex and appearance are produced from the same original egg. The possibility of human cloning, raised when Scottish scientists at Roslin Institute created the much-celebrated sheep "Dolly", aroused worldwide interest and concern because of its scientific and ethical implications. Look at pictures.

T: Look at the pictures and discuss how natural clones and man - madeclones differ.

Step II Pre-reading

Before class, ask the students to search for some information about this topic.

T: Now enjoy a flash which shows how the procedure of a clone, trying to find out the answer to this question: Which sheep is Dolly's mother in genetics?