Book 8 Unit 2 Cloning Warming up and Pre-reading. 背景阅读Cloning is the technique of producing a genetically identical duplicate of an organism. A clone is said to be all descendants derived asexually from a single individual, as by cuttings, bulbs, by fission, by mitosis, or by parthenogenesis reproduction. It sounds very different and complicated to us. In fact, 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 fact is that cloning plants is straightforward but the cloning of animals is more complicated. 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. She was the first mammal to be cloned from adult DNA taken from an adult cell. Previously, animals had only been cloned using embryo cells which already have the potential to become a complete embryo in its own right. The big breakthrough with Dolly was to make a clone from an ordinary, adult cell in this case from a female goats udder. 1. Fill in the blanks according to the passage.1) The definition of cloningCloning is a _ of producing a genetically identical duplicate of an animal or a plant. It happens both in _ and in_. They can be cloned by _ or humans. The former is_clone while the latter is man-made clone. 2) How does Dolly differ from other sheep?She was _ by humans while the others were born naturally.So, Dolly was a _ sheep.2. Discuss the following questions. 1). Can you see any cloning happen in our daily life?2). What benefits can humans gain from cloning?3). What problems may arise when humans are cloned?4). Should we clone a human?5). Could cloning replace sex as the means of creating new human life?6). Could a parent clone a child who is dying of a terminal illness?ReadingI. Reading comprehension:1. The main idea of the text is_ A. animal cloning is very valuable and can benefit the world. B. animal cloning could be misused by bad people so it must be forbidden.C. animal cloning is well developed because Dolly the sheep was born. D. animal cloning raised arguments and scientists are not sure about its future.2.The cloning of Dolly the sheep succeeded because_. A. its easier to clone a sheep than other animals B. the scientists were determined and worked hard with patienceC. the scientists were rewarded and got lots of moneyD. many other attempts to clone mammals failed3. What is the writers attitude toward cloning in this passage?A. The writer is against cloning.B. The writer is in favor of cloning.C. The writer is neutral towards cloning.D. The writer is in agreement with cloning.4. Which of the following is not an advantage of cloning?A. Cloning can be used for medical purposes. B. Large quantities of food can be produced by cloning.C. Cloning can help keep animals from becoming extinct.D. People can clone themselves at will.5. We can infer from the last three paragraphs that _.A. The normal development of Dolly had no effect on the cloning of other species.B. Dollys serious disease and final death disturbed the whole world.C. Dolly successfully cloned a new lamb with the help of cloning scientists.D. There were arguments about animals about animal cloning and concerns about the future of cloning.6.What is the writing style?A. Expositive （说明性的） B.Descriptive C. Argumentative （议论性的） D. NarrativeII. Fast reading: True or False questions1. Cloning means making a copy of an animal or a plant. 2. Gardeners can make a lot of money by cloning plants. 3. Cloning animals is as complicated as cloning plants. 4. Dolly the sheep was the first successful clone of a mammal. 5. Natural clones happen in animals as well as in plants.III. Fill in the chart using the information from the text. Add one reason of your own in each column.Problems or dangers of cloningAdvantages of cloningAnimals may_ _ of older animals.Medical cloning could _ _ for serious degenerative(变质的）_ in humans.Animal clones may _ than the donor animalsCloning plants can _ of similar _ _ _ ._ _ may want to clone t