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Book 3, Unit 8 CLONING. First Stem Cells Extracted from Cloned Human EmbryoPosted: 02.17.04 Scientists in South Korea have extracted stem cells from a.

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Presentation on theme: "Book 3, Unit 8 CLONING. First Stem Cells Extracted from Cloned Human EmbryoPosted: 02.17.04 Scientists in South Korea have extracted stem cells from a."— Presentation transcript:

1 Book 3, Unit 8 CLONING

2 First Stem Cells Extracted from Cloned Human EmbryoPosted: Scientists in South Korea have extracted stem cells from a cloned human embryo - a breakthrough that has potential for treating various diseases but also ignites fears that rogue scientists will use the technology to clone humans. Part I: Pre-Reading Task

3 Other scientists have cloned small numbers of human embryos that lived for a short time, but the South Koreans who announced their work last week in the journal Science, apparently succeeded on a scale that far outstripped earlier human cloning efforts.

4 South Korean researchers make medical history The researchers began with a group of 16 women who were given hormone treatments to produce large numbers of reproductive egg cells. They eventually obtained 242 eggs from the women. Then the scientists used innovative techniques to strip out the nucleus from each of these egg cells. The nucleus is the portion of the cell containing many of the cell's genetic instructions.

5 The scientists next took body cells from the same women who had donated the egg cells. The body cells have two sets of chromosomes, the full genetic blueprint needed to create a human being. The scientists removed these body cells' nuclear material and placed it into the egg cells.

6 The result was 66 cloned eggs, in effect, human embryos, with the exact genetic makeup of the original females. The researchers grew 30 of the embryos for a week to the so-called blastocyst stage, when stem cells could be extracted

7 Stem cell technology could help cure diseases Embryonic stem cells are unique because they have the potential to develop into any type of tissue or cell in the body. The research, called therapeutic cloning, could allow scientists to take a plug of skin or blood sample from a patient and use it to grow tissue, organs or batches of cells. The new cells would have the same genetic makeup as the donor and would therefore lower the risk that the injured or sick person's body would reject the new tissue.

8 "Our approach opens the door for the use of these specially developed cells in transplantation medicine," said Woo Suk Hwang, who led the government-funded study. Researchers also hope the stem cell research will lead to treatments for a range of diseases from Alzheimer's to Parkinson's to diabetes.

9 Ethical questions But embryonic stem cell research is controversial because harvesting the cells destroys an embryo that could have grown into a baby if implanted in a woman's uterus. President Bush is against making and destroying human embryos. "The use of embryos to clone is wrong. We should not as a society, grow life to destroy it," he said in The Bush administration policy does not allow the government to fund any research on stem cells taken from embryos destroyed after Aug. 9, Since the research is expensive, the ban has limited the amount of work being done in the United States.

10 Reproductive vs. therapeutic cloning Some fear that the South Korean scientific advance will encourage people to create human clones, called reproductive cloning. In reproductive cloning, which has been performed with animals but not people, the embryos are implanted in the womb and allowed to develop into a fetus. In therapeutic cloning, the embryos are never implanted, but are grown for a few days in the laboratory so that the stem cells can be extracted. The first mammal was cloned in 1996 when Scottish researchers made Dolly the sheep. Dolly died a year ago of what scientists said was premature aging and complications from cloning. Most scientists believe human reproductive cloning is unethical because any baby created by this method would be prone to severe deformities.

11 Scientific research in the United States While many U.S. lawmakers would like to ban human reproductive cloning, the debate is complicated by the question of whether to allow therapeutic cloning. Conservative lawmakers have attached bans on embryonic stem cell research to all bills regarding reproductive and therapeutic cloning, preventing Congress from coming up with a clear policy. Some U.S. scientists worry that the lack of government support for all cloning related to humans is already harming the future of American medical research. "We will be sitting here with the best scientists in the world watching things on television," Dr. Jose Cibelli, professor of animal biotechnology at Michigan State University told the New York Times. Cibelli collaborated with the South Korean scientists and is an author of their paper. Several countries in Europe ban all human cloning, including therapeutic cloning.

12 Reading Comprehension Questions: 1. Explain how the South Korean scientists created the stem cells. 2. Why are embryonic stem cells so interesting to scientists? How can this research be applied to medical treatments? 3. Why is embryonic stem cell research controversial? 4. Why does President Bush want to limit embryonic stem cell research? 5. How is reproductive cloning different from therapeutic cloning? 6. Why hasn't the United States banned human reproductive cloning?

13 Keys: 1. Explain how the South Korean scientists created the stem cells. The scientists took body cells from 16 women who were given hormone treatments to produce large numbers of reproductive egg cells. The body cells have two sets of chromosomes, the full genetic blueprint needed to create a human being. The scientists removed these body cells' nuclear material and placed it into the egg cells. The result was 66 cloned eggs, in effect, human embryos, with the exact genetic makeup of the original females. The researchers grew 30 of the embryos for a week to the so-called blastocyst stage, when stem cells could be extracted. 2. Why are embryonic stem cells so interesting to scientists? How can this research be applied to medical treatments? Embryonic stem cells are unique because they have the potential to develop into any type of tissue or cell in the body. The research, called therapeutic cloning, could allow scientists to take a plug of skin or blood sample from a patient and use it to grow tissue, organs or batches of cells. The new cells would have the same genetic makeup as the donor and would therefore lower the risk that the injured or sick person's body would reject the new tissue. 3. Why is embryonic stem cell research controversial? Embryonic stem cell research is controversial because harvesting the cells destroys an embryo that could have grown into a baby if implanted in a woman's uterus.

14 keys 4. Why does President Bush want to limit embryonic stem cell research? Harvesting the cells destroys an embryo that could have grown into a baby if implanted in a woman's uterus. President Bush is against making and destroying human embryos. "The use of embryos to clone is wrong. We should not as a society, grow life to destroy it," he said in How is reproductive cloning different from therapeutic cloning? In reproductive cloning, which has been performed with animals but not people, the embryos are implanted in the womb and allowed to develop into a fetus. In therapeutic cloning, the embryos are never implanted, but are grown for a few days in the laboratory so that the stem cells can be extracted. 6. Why hasn't the United States banned human reproductive cloning? While many U.S. lawmakers would like to ban human reproductive cloning, the debate is complicated by the question of whether to allow therapeutic cloning. Conservative lawmakers have attached bans on embryonic stem cell research to all bills regarding reproductive and therapeutic cloning, preventing Congress from coming up with a clear policy.

15 Part II Cultural Notes: 1. clone: a group of organisms or cells that are genetically identical, having been produced from one parent by asexual reproduction. The individual organisms or cells are precise copies of the parent and genetically identical to it. Clones are found naturally among single-celled organisms ( such as bacteria), a few invertebrates (such as corals), and some asexually reproducing plants ( as in the production of runners by a strawberry plant). In agriculture, plant cloning can be used to advantage, in that individuals with desirable properties, such as pest-resistance or high growth rates, can be replicated exactly without the unpredictable results associated with sexual reproduction. Artificial cloning of animals and cells can be achieved by teasing apart the cells of the early embryo. Similarly, cells capable of growing into mature plants can be obtained from plant growth-regions (meristems). In genetic engineering cloning refers to the copying of DNA molecules.

16 2. genetic engineering: the deliberate modification of the genetic make-up(genome) of an organism by manipulation of its DNA. Genetic engineering techniques include cell fusion and the use of recombinant DNA (r DNA). Since the late 1960s these techniques have held out the most exciting promise for biotechnology. In such a new field controversy inevitably abounds. Worries concerning release of genetically novel bacteria into the environment, or the possible manipulation of human embryos, have led to the setting up in the USA of the Genetic Manipulation Advisory Group (GMAG). Legislation governing genetic research has also been passed in several other countries.

17 3. NARCISSUS ( in Greek mythology): a beautiful youth who spurned the love of the nymph Echo and in punishment was made to fall in love with his own reflection; he pined away gazing at himself in a pool and at his death was changed into the flower bearing his name narcissus.

18 4. Prometheus: in Greek mythology, a Titan who made the first man from clay and stole fire from the gods to give to mankind. In revenge for the theft, Zeus chained Prometheus to a rock, where his liver was eaten every day by an eagle, only to grow again ever night. Herecules eventually rescued him. Prometheus has been seen as a symbol of reedom, rebellion against tyranny, and of creative imagination.

19 5. Oppenheimer, ( Julius) Robert ( ): US physicist. He was appointed in 1942 as director of the Manhattan Project, the secret project to develop the atomic bomb in the USA during World War II, based at Los Alamos, New Mexico, which in 1945 made the first atomic bomb. In 1953, at the height of the witch-hunting campaign led by the US Senator Joseph McCarthy, Oppenheimer was excluded from sensitive research on the grounds that he had Communist sympathies, but subsequently (1963) he was unreservedly rehabilitated.

20 6. Hiroshima: Japanese city in southern Honshu. Hitherto largely undamaged by the US bombing campaign, Hiroshima became the target of the first atomic bomb attack on 6 august 1945, which resulted in the virtual obliteration of the city centre and the deaths of about one-third of the population of 300,000. The attach on Hiroshima, together with that on Ngasaki three days later, helped bring about Japan’s unconditional surrender and the end of World War II.

21 7. Nagasaki: Japanese city in Kyushu. On 9 August 1945, three days after the first atomic bomb attack on Hiroshima, Nagasaki became the next target. The hilly terrain protected the population of 230,000 from the full effects of the explosion, but 40,0000 people were killed and tremendous destruction caused. On the following day Japan offered to surrender and the ceasefire began on 15 August, the official surrender finally being signed on 2 September.

22 Part III Language Points: 1. clone: any of a group of plants or animals produced from the cells of a single ancestor and therefore exactly the same as it is. e.g. Researchers produced clones from adult mice in Although two clones are identical genetically, they may develop in different ways. e.g. Researchers in Japan have cloned eight calves from the cells of a single adult cow. The idea of cloning extinct life forms still belongs to science fiction. Experiments to try to clone human embryos have met with hostility from some sections of the public.

23 2. give birth to: 1) bear (a bird), bring forth e.g. Although a mother panda often gives birth to two cubs, she usually abandons one of them without attempting to care for it. The research has shown that mothers who smoke give birth more frequently to premature or underweight babies. create, originate e.g. The extraordinary experience gave birth to his latest novel. Einstein gave birth to a whole new way of looking at matter and energy. 3. for all the world: in every respect; exactly e.g. I felt for all the world as if I was still a child. He looked for all the world like a country doctor.

24 4. dot: spread things or people in various separate places over an area e.g. From the top floor we could see the trees dotting the landscape. The sky was dotted with stars. n. a small round mark e.g. He forgot the dot on the letter i and so it looked like and 1. The stars just look like thousands of tiny dots of light. 5. union: a uniting or being united; combination; an organization of workers form a particular profession, an association or club. e.g. Marriage is a socially recognized and approved union between individuals. Labor unions bargained with employers to determine issues such as wages, conditions of work, and worker security.

25 6. fuse: ( cause to ) join together ( followed by with) e.g. Nearly 50 percent of the cumulus cells that successfully fused with an egg developed into an advanced embryo. Genes determine how we develop from the moment the sperm fuses with the egg. 7. gene: a unit in a chromosome which controls inherited characteristics e.g. Genetics is the study of the function and behavior of genes. The human Genome Project has to far identified nearly all of the estimated 31,000 genes in the nucleus of a human cell. The DNA is divided into units called genes, just like a long train is divided into separate cars.

26 8. take up: go and live; move into ( a certain position) e.g. The hunter took up his quarters in a hut. As the crowd grew, riot police took up their positions. UN peacekeeping forces are expected to take up positions along the Afghanistan border. 9. residence: the fact of living in a particular place e.g. He took up his permanent residence in China. Campus residence halls provide common settings for students to form new bonds with peers who share similar experiences. More immigrants were admitted to the United States for permanent residence in recent years.

27 10. identical: exactly alike or equal; the very same ( followed by to) e.g. The journalist David Rorvik wrote a true story of a billionaire’s quest to produce a son identical to himself. Although Euro bills are identical in all countries, each country can issue its own coins. 11. twin: persons who have the same mother and were born on the same day e.g. The two boys looked like twins. He has a twin brother and a younger brother. Unlike my friend, I think there are many positive aspects to being a twin. 12. beforehand: in advance; earlier e.g. Catherine got married without telling anyone beforehand. Mum had done most of the cooking beforehand, so we weren’t tied to the kitchen.

28 13. oppose: express strong disapproval with the aim of preventing or changing a course of action: resist e.g. My father opposed my wish to become a musician. The local residents strongly opposed the chemical companies dumping their waste in the sea. be opposed to : be against e.g. We are utterly opposed to any form of terrorism. They are strongly opposed to the presence of American troops in this region. 14. theoretical: concerned with the theory of a subject; based on theory e.g. Information theory is primarily a theoretical study. With his brilliant theoretical work, Albert Einstein revolutionized 20th century physics. Aristole defined the basic concepts and principles of many of the theoretical sciences, such as logic, biology and physics.

29 15. in principle: as far as basic principles are concerned e.g. In principle, clones may even be essentially immortal, dying only from disease or the deterioration of the environment. In principle, Quantum theory could be used to predict the behavior of any physical, chemical, or biological system. 16. offensive: causing sb. To feel upset, insulted or annoyed e.g. Minority groups are protected from hateful and offensive speech and actions on campus. The document did not appear to contain any offensive statements. 17. compromise: a settlement in which each side gives up some demands e.g. In order to reduce carbon monoxide emissions from motor vehicles but at the same tieme develop the industry, a compromise was reached. The two countries continued to have difficulties reaching a compromise on a solution to the problem of acid rain. v. (used in the patterns: compromise with sb. Over sth., compromise on sth.)

30 18. potential: the possibility of sth. Happening or being developed e.g. The potential for abuse of genetic engineering has presented society with many ethical and legal controversies. The best single indicator of a state’s great-power potential may be its total Gross Domestic Product (GDP). Volcanoes have the potential to create some of the planet’s most formidable natural disasters. a. that can, but has not yet, come into being; possible e.g. In large cities with a million or more potential customers, there are much larger clothing stores with many more choices of items and styles. In the article Wilmut discussed potential medical uses for cloning, and ethical issues surrounding cloning technology. Scientists can only speculate on the potential impact of the depletion of the ozone layer.

31 19. tolerate: allow (sth.) that one does not like to happen or continue: put up with e.g. College president sent letters to every student saying that drugs on campus would not be tolerated. Teachers will not tolerate cheating on exams, just as parents will not let their children lie and get away with it. 20. ancient: belonging to times that are long past e.g. Furniture designs have reflected the fashion of very era from ancient times to the present. Hebrew is an ancient language that became extinct, but has now been brought back to life and is spoken today.

32 21. catalog: (also catalogue) a complete list of items e.g. Users outside the library can access millions of bibliographic records, including the entire card catalog, through the Internet. Dell sells its products directly to customers through the Internet and mail order catalogs rather than through retail outlets. 22. terrify: make (sb.)very frightened e.g. Flying has terrified some people since the terrorists attack on the World Trade Center. The gunman’s threats terrified her into handing over the money.

33 23. normally: under normal circumstances; ordinarily e.g. During 26 years of research on sharks I have found them to be normally unaggressive and even timid toward man. Greatly affected by E1 Nino, areas that are normally wet, such as Indonesia, the Philippines and eastern Australia have experienced drought. 24. mixture: a combination of two or more things or styles e.g. A mixture of cultures form around the world is reflected in the street festivals and ethnic celebrations in New York City. Offspring receive a mixture of genetic information from both parents. Smog, a mixture of smoke and fog, irritates the eyes, throat, and lungs and also damages plants.

34 25. brilliant: very intelligent; extremely clever e.g. With his brilliant theoretical work, Albert Einstein revolutionized 20th century physics. It was his brilliant performance in Hamelt that established his reputation. The Hubble telescope is a brilliant new device that allows us to peer far more deeply into heavens. 26. inherit: 1) have features or qualities from an ancestor e.g. Although all humans share the same set of genes, individuals can inherit different forms of a given gene, making each person genetically unique. Deficiencies in immune function may be either inherited or acquired. While people biologically inherit many physical traits and behavioral instincts, culture is socially inherited. 2) receive (money, property, etc. of an ancestor) e.g. He has no son to inherit his land. Mary inherited the money form her parents.

35 27. comment: a written or spoken remark giving an opinion e.g. He was making rude comments about her haircut. There has been no comment so far from police about the bomb attack happening yesterday. v. (followed by on) e.g. The president refused to comment on the issued of gun violence on campus. The teacher commented on the fact that some students were absent for class. 28. genius: (a person who has) exceptionally great creative ability e.g. Thomas Edison is considered a genius of invention. From the age of three, she showed signs of genius.

36 29. atomic: concerning atoms or the energy released by them e.g. On August 6, 1945, the United States dropped an atomic bomb on Hiroshima, Japan. As the atomic nuclei are fused together, an extraordinary amount of energy is released. 30. curiosity: a strong desire to know and learn (followed by about) e.g. Science museums stimulate curiosity and allow people to learn at their own space. As a youth Einstein showed a brilliant curiosity about nature and an ability to understand difficult mathematical concepts. My daughter showed an enthusiasm and curiosity about Chinese history. 31. let loose: set free; release e.g. Don’t let that dog loose in the yard, as it will terrify the kids. Trainees will go through a four-hour lesson before they are let loose on the controls.

37 32. transplant: 1) remove tissue or an organ form one person or animal and put it into another e.g. To repair injuries such as burns, skin is sometimes transplanted from one area of the body to another. The operation to transplant a kidney is now fairly routine. 2) remove a growing plant with its roots and plant it elsewhere e.g. Tea was transplanted from China to India and Sri Lanka. The seedlings can be transplanted when they are bout four inches tall. n. transplant(ation) e.g. In some instances, surgeons may perform a lung transplant to save a patient’s life. Cloning may generate genetically modified animal organs that are suitable for transplantation into humans. Advances in organ transplantation have brought new hope to those afflicted with diseased organs.

38 33. lash out at: make a sudden violent attack at with blows or words e.g. He lashed out at them with his fists. It seemed that he was going to lash out at the saleswoman, but he controlled himself. 34. immune: 1) protected against through the body’s natural resistance (followed by to) e.g. The health of the body is dependent on the immune system’s ability to recognize and then destroy bacteria and viruses. A healthy immune system protects the body against bacteria, viruses, and other harmful agents. It seemed for a while that infants were immune to Aids. My brother seems to be immune to colds-he just never gets them. 2) not affected by sth. (followed by to) e.g. Football is not immune to economic recession.

39 35. merge: (cause to ) combine e.g. In the great melting pot like New York City cultures are merged and traditions lost. In the story he merged his mind with the robot’s and shared its thoughts. The two colleges will be merged to form a university. 36. primitive: of or at an early stage of development e.g. An examination of two fossils reveals that a primitive human species had arrived in Asia from Africa about 2 million years ago. With the discovery in 1996 that primitive life may have flourished early in the history of Mars, interest in exploring the planet increased. The most commonly cited example of a primitive calculating device is the abacus.

40 37. start out: 1) intend when starting e.g. They started out wanting a house, but eventually bought a flat. Peter didn’t start out to apply for Yale University-it just happened that way. 2) begin e.g. He started out in the personnel department; later he was transferred to the sales department. She started out as a teacher and only began writing in his thirties. 38. grow into: become gradually as time passes e.g. With the construction of the highways, the village is growing into a town. She is growing into a beautiful young woman.

41 39. batch: the amount (of bread, etc.) produced at one baking; a number of things taken as a group; lot e.g. The second batch of sugar was better than the first. Harvard University biologist Dick Estes supplied a large batch of lion photographs taken from 1963 to The school authorities have laid down a great batch of rules and regulations.

42 Part IV Text Organization: The text can be divided into four parts. The paragraph numbers of each part have been given to you. Now write down their main ideas. PartsParagraphsMain Ideas Part OneParas 1-2 Part TwoParas 3-6 Part ThreeParas 7-11 Part FourParas 12-16

43 Keys: Part One: Dolly the sheep, a clone, was born. Part Two: Dolly’s birth has made cloning a reality and human cloning a possibility. Part Three: People have to face the ethical problems of human cloning. Part Four: Cloning technology could benefit people in more than one way.

44 2. If you examine Part 3 carefully, you’ll find it can be further divided into two sections. Please write down the paragraph numbers of each section and its main ideas. SectionsParagraphsMain Ideas Section One Paras 7-9 Section Two Paras 10-11

45 Keys: Section one: Human cloning has given rise to the question of what implications the technology may have for mankind. Section two: The making of the atomic bomb had a tremendous impact on scientists.

46 Part V Language Focus: You need to study carefully all the key words and phrases in the box. We have a number of exercises to help you learn how to use them. Words and Phrases to Drill ancient atomic batch beforehand brilliant catalog clone comment compromise curiosity dot fuse gene genius identical immune inherit merge mixture normally offensive oppose potential primitive residence terrify theoretical tolerate transplant twin union be opposed to for all the world give birth to grow into in principle lash out at let loose start out take up

47 1.Fill in the gaps with words or phrases chosen from the box. Change the form where necessary. 1) A green card is a registration card, originally green, granting an alien permanent ___________________ in the United States. 2) It was Marx’s ideas that _____________________ communism. 3) In Istanbul, east and west ______________together in a way that is fascinating to observe. 4) The _______________ surgery of those days left my sister virtually deaf in one ear. 5) You inherit half your _______________from your father and half from your mother.

48 6) In a ______________between management and unions, a 4% pay rise was agreed in return for an increase in productivity. 7) Her house is furnished in a curious _______________ of old and modern styles. 8) The Euro is a unit of currency that is used by a dozen countries that have joined the European monetary( 货币的 ) _________________. 9) I knew Michelle was coming that afternoon because she had phoned me _____________. 10) What _______________as fun quickly became hard work.

49 11) The police chief has made no _______________about the attack so far. 12) You don’t have to go to a store to buy things now. You can buy them on line or through a mail-order _________________. 13) This is certainly a ________________risk but in practice there is seldom a problem. 14) Susan sounds for _________________like her mother on the telephone. 15) Some educators advocated a bilingual education in schools but many parents vigorously _________________it.

50 Keys: 1) residence 2) gave birth to 3) fuse 4) primitive 5) genes 6) compromise 7) mixture 8) union 9) beforehand 10) started out 11) comment 12) catalog 13) theoretical 14) all the world 15) opposed

51 2. Use the verb in brackets to form an appropriate phrasal verb and complete the sentence with it: Model: What _____________to be a clone of you could grow into a batch of your marrow—the perfect match. (start) What started out to be a clone of you could grow into a batch of your marrow— the perfect match.

52 1) Computer programming is the sort of work that ______________a high level of concentration. (call) 2) As I sat up very late last night, I ______________with a headache this morning. (wake) 3) As the crowd grew, riot police ( 防暴警察 ) _________________their positions. (take) 4) If you are not sure how to go about organizing a party, go and ask Millie. She never ________________ideas for such things. (run)

53 5) He is a small man with a big ego ( 自我 )-that about _______________him_______________, doesn’t it? (sum) 6) When the coach waslaid up with pneumonia, the training rules of the team________________. (break) 7) The senator _________________the administration for its failure to come up with effective measures to deal with the economic recession. (lash) 8) Old John has accumulated a large fortune in the past few years but he never donates anything to charity; he _________________ an old miser ( 吝啬鬼 ). (grow)

54 Keys: 1) calls for 2) woke up 3) took up 4) runs out of 5) sums…up 6) broke down 7) lashed out at 8) has grown into

55 Part VI Comprehensive Exercises: 1. Cloze ( A ) Complete the following passage with words chosen from the Words and Phrases to Drill box. Change the form where necessary. “What do you think of ______________(1)?” “What, like Dolly the sheep, that sort of thing?” “That’s right.” “Personally, I _______________ ______________ _______________(2) it. It seems far too dangerous and could lead to all sorts of __________________(3) results.”

56 “I had no idea you found it so _______________(4). You don’t _________________(5) oppose such things.” “Well, this seems to me to be one case where we are taking human ______________(6) too far.” “Well, I can’t say that I’m against it ______________ ______________(7). It seems to have the __________________(8) to do a lot of good. What about ________________(9) from one person to another? They say that cloning can help get over problems of rejection by the _______________(10) system.” “But what if some evil _________________(11) were to misuse the idea? Do you remember that film, The Boys from Brazil, all about a German scientist who was reproducing _____________(12) copies of Hitler?” “Oh, come on. Now you really are letting your imagination run away with you !”

57 Keys: 1) cloning 2) am opposed to 3) terrifying 4) offensive 5) normally 6) curiosity 7) in principle 8) potential 9) transplanting 10) immune 11) genius 12) identical

58 ( B ) Fill in the gaps with any words you think fit: Since Dolly came into existence, scientists and politicians have been worrying about the prospect that it will soon be possible to clone humans, too. The debate centers ____________(1) two types of cloning: reproductive, with the intention of ______________(2) a baby, and therapeutic( 治疗的 ), with the aim _______________(3) creating a source of “embryonic” stem cells ( 干细 胞 )_______________(4) might replace diseased organs of the body. Cloning has ________________(5) strong supporters and fierce critics. ______________(6) the deeply held moral and technological objections of many people, human cloning __________________(7) a small step forward this week ________________(8) an announcement by researchers that they had successfully created a _________________(9) embryo through

59 cloning, _________________(10) the purpose of developing stem cells. They are ________________(11) the first to lay claim to such a feat, _________________(12) they are the first to publish their findings. Their work was promptly condemned _______________(13) President George Bush, _________________(14) said it was morally wrong, and by the Vtican, among many others. From a technical standpoint, such strong ________________(15) seems out of line with the slender scientific significance ____________________(16) this development. The researchers used ________________(17) has become standard cloning method in animals. This is to remove the nucleus( 核 ) containing genetic materials__________________(18) a donor egg, and replace it _________________(19) the nucleus of another cell. The resulting stem cells would then be genetically identical to the donor, avoiding problems of rejection _________________(20) they are returned to the patient in treatment.

60 Keys: 1) on 2) producing 3) of 4) that/which 5) both 6) Despite 7) took 8) with 9) human 10) for 11) not 12) but 13) by 14) who 15) opposition/condemnation 16) of 17) what 18) from 19) with 20) when

61 Part VII Translation: Translate the following passage into English, using the words and phrases given below: identical offensive twin clone terrify batch immune tolerate transplant grow into potential 多利羊诞生之后,克隆就再也不能当作科学幻想而不去认 真考虑了。人们能够复制一头一模一样的羊,这与克隆人 仅有一步之遥。许多人觉得克隆人很可怕,令人反感。 但是,这一技术具有极大的医药应用潜力。科学家可以培 养一群细胞,并指令它们长成与病人基因完全一致的整个 器官甚至四肢,这就消除了器官移植到病人体内时因免疫 反应造成的排异问题。科学家们还可以从改基因的动物譬 如猪身上获取一个接受移植的病人能够容忍的器官。这样, 现在每年成千上万个因为得不到可替换的心、肝或肾而死 亡的病人的生命就可以得救了。

62 Keys: After Dolly was born, cloning could no longer be dismissed as science fiction. The ability to create an identical twin of a lamb is but one step short of cloning humans, which many find terrifying and offensive. However the technology holds great potential for medical application. Scientists could cultivate a batch of cells and direct them to grow into whole organs or even limbs that will be genetically identical to the patient, thus eliminating the problem of rejection caused by immune reaction when they are transplanted into his body. Or they could take an organ from animals such as pit that has been genetically altered so that it will be tolerated by the recipient. Then the lives of thousands of patients who die every year before a replacement heart, liver or kidney becomes available would be saved.

63 Test B Second Thoughts on Cloning Key Words Exercises: Fill in the gaps with words or phrases lists below. Change the form where necessary. enhance condemn overcome rest on artificial inevitable significant by virtue of in essence vital prospect necessarily vague is bound to lend…support to objection subscribe to come to terms with have second thoughts prohibiting

64 1. Martin has been assigned to work in the company’s Beijing office, and the ____________of living in a foreign city excites him. 2. The new product is expected to ____________their reputation as a leading IT company. 3. Brookman & Langdon is said to manufacture the most desirable pens and these _____________command astonishingly high prices. 4. Political leaders at the conference united to ________________the terrorist attacks on the World Trade Center in New York. 5. Unfortunately, the victim of the attempted murder only has a _______________memory of what his attacker looked like.

65 6. Courage is not the absence of fear. It is the ability to ______________fear. 7. The bridge was poorly designed and hastily built. It _____________collapse. 8. The future of a nation ______________its youth. That’s why education of the young is of such vital importance. 9. The community _______________full ______________the building of a park in the neighborhood. 10. The dying old general did not want his life to be prolonged by ______________means.

66 11. No one took seriously the ________________to the proposed program until it was too late. 12. Four successive dry winters had made water shortage _____________. 13. I’ve personally never _______________the view that man should save nature for its own sake. 14. In the printed version of his speech, the speaker made a small but _______________change. 15. At first she found it hard to ________________the fact that she, a model worker, had been laid off by the factory.

67 16. He believed that it is wrong that some people should enjoy wealth, privilege, influence and power solely _____________an accident of birth. 17. We ________________about buying the house when we met the neighbors. 18. In detail the class system is complex, but _______________it is simple. 19. I think the government should introduce a law __________________artificial additives( 添加剂 ) in children’s food. 20. Her release enabled her to give _______________information about her kidnappers( 绑 架者 ).

68 Keys: 1) prospect 2) enhance 3) necessarily 4) condemn 5) vague 6) overcome 7) was bound to 8) rests on 9) lent…support to 10) artificial 11) objections 12) inevitable 13) subscribed to 14) significant 15) come to terms with 16) by virtue of 17) had second thoughts 18) in essence 19) prohibiting 20) vital

69 THE END THANKS FOR YOUR ATTENTION! THE END THANKS FOR YOUR ATTENTION!


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