人教高中英语选修八unit-2-Warming-up-and-Reading课件.pptxVIP

Unit2 Cloning; No two leaves are identical in the world. ;Look at the pictures and discuss which ones are natural clones and which ones are man-made clones .;A strawberry plant;A strawberry plant;Growing new plants;富贵竹插枝即活;man-made clone examples ; Dolly, the first mammal to be cloned from adult DNA, was put down by deadly injection on Feb. 14, 2003. Before her death, Dolly had been suffering from lung cancer and crippling arthritis (严重的关节炎). ;2001 cloning cattle;2005 cloning dogs;Natural clone is one that occurs in nature without human help. ;A clone is an animal or plant produced naturally or artificially from the cells of another animal or plant and is exactly the same as it. Cloning is a way of making an exact copy of another animal or plant. The clone has the same DNA as the parent. ;The mule in the picture is the world’s first cloned mule. It was born on 4 May 2003. His name is Idaho Gem. ;The kitten in the picture is called Cc. Its name is from “Copycat”. ;These female pigs are also cloned. They are born on Christmas Day 2001. They are Noel, Angel, Star, Joy and Mary.;The pair of calves were born on 5 July 1998 in Ishikawa, Japan. They were two years younger than Dolly, being second adult animal clones in the world.;Important events in cloning history;In 5000 B.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.;;;1 Clone can be from both natural clone and man-made clone. 2 The sheep, named Kitty was the first successful clone of a mammal. 3 Only strawberries and cactuses (仙人掌) are natural clones. 4 Since Dolly, researchers have cloned a number of large and small animals including cats, rabbits and horses.;Oh! My God! I was cloned!;;These expressions may help. ;1.By cloning, farmers can produce quantities of different commercial plants.; 2.Medical cloning can help cure serious illnesses that ruin one’s quality of life