Unit2P1Warmingup课件新人教选修6.pptVIP

Cloning ;Cloning?;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. ; There are different types of cloning, and cloning technologies can be used for other purposes besides producing the genetic twin of another organism. The three types of cloning technologies are: (1) recombinant DNA technology or DNA cloning（基因重组克隆技术） (2) reproductive cloning（再生克隆技术） (3) therapeutic cloning （干细胞疗法克隆技术）;In pairs, look at these pictures and discuss which ones are natural clones and which ones are man-made. Think about how they differ.;Dolly the sheep;一株草莓依靠它沿地“爬走”的匍匐茎, 一年内就能长出数百株草莓苗。;Growing new plants;Natural clone is one that occurs in nature without human help. ;Cactus(仙人掌);;man-made clone examples ; Dolly, the first mammal to be cloned from adult DNA, was put down by lethal injection on Feb. 14, 2003. Prior to her death, Dolly had been suffering from lung cancer and crippling arthritis (严重的关节炎). ;Dolly是世界上第一例用体细胞─乳腺上皮细胞, 通过细胞核移植技术, 在复杂的人工操作下, 得到的一只小绵羊 。;Scientists have been cloning animals for many years. The creation of Dolly is the first mammal cloned from the cell of an adult animal. Since Dolly, researchers have cloned a number of large and small animals including sheep, goats, oxen, mice, pigs, cats, rabbits and so on. All these clones were created using nuclear transfer technology（细胞核移植技术）. ;2002年4月16日美国第一头克隆牛“艾米”产下牛犊喜作妈咪。 ;2002年5月中旬成功地繁殖了一只胚胎细胞克隆兔。 ;第一只克隆猫;克隆马及其“母亲兼姐姐”;克隆的荧光小猪(左)和正常小猪(右);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 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)