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⾼考英语⼀轮复习话题37克隆（Unit2Cloning）新⼈教版选修8话题37 克隆（Unit 2 Cloning）晨读背诵When the media report on cloning in the news, they are usually talking about only one type called reproductive cloning. There are different types of cloning however, and cloning technologies can be used for other purposes besides producing the genetic twin of another organism.Scientists have been cloning animals for many years. In 1952, the first animal, a tadpole, was cloned. Before the creation of Dolly, the first mammal cloned from the cell of an adult animal, clones were created from embryonic cells. Since Dolly, researchers have cloned a number of large and small animals including sheep, goats, cows, mice, pigs ,cats, rabbits, and a gaur. All these clones were created using nuclear transfer technology.汉语⼤意：当媒体报道的克隆的消息，他们通常所说的只有⼀种称为⽣殖性克隆的类型。
克隆技术与人类发展继多利羊诞生之后，羊、牛、猪、鼠、兔、猫乃至猴这种与人类特征最为相近的灵长类动物都陆续拥有了各自的克隆版本。
但毫无疑问，克隆技术依然处于“萌芽状态”，人类要达到完全熟练掌握并安全利用克隆技术的目标，尚需时日。
培育出多利的英国苏格兰罗斯林研究所所长格里芬指出，迄今所有动物克隆试验中，平均只有1%～2%的克隆胚胎可以成活。
尽管随着技术的发展这一比例有望得到不断提高，但“鉴于物种的多样性，对非人类生物进行的克隆技术研究的成果应用到人类自身时，并不能确保安全”。
虽然如此，但仅仅从技术上来说，不断取得的科研进步总有一天会研制成克隆人。
人们对这一天的到来甚为担忧，充满了恐惧。
确切地说，这是对滥用克隆技术可能给人类自身带来危害的恐惧。
专家们围绕在克隆研究方面划分禁区的问题争论不休，其核心在于将克隆技术的应用控制到哪一步才是安全的。
正如德国教育和科研部部长布尔曼女士所说，“目前对克隆技术不同的科研方法和目标的定义还不是很明确”，生殖性克隆研究与医疗性克隆研究之间的暧昧关系难以界定，恐怕才是专家们最为头疼的问题。
以医治疾患为目的而对人类胚胎进行克隆，和以生殖为目的而使克隆胚胎最终成为一个降临人世的生命，两者之间隔着的不过是一张薄薄的纸而已。
克隆人带来的诸如导致物种灭绝、历史人物复生等种种缘于无知的恐慌逐渐消退，至今悬而未决的伦理与道德等方面的冲击也难以构筑起阻止克隆人问世的路障。
在这样的背景下，政治家们急切地盼望通过立法规范克隆技术的研究和发展。
但即便是全球立法禁止克隆人研究，也难保没有偏执的“科学疯子”继续尝试。
克隆技术不是第一项也不会是最后一项使人类陷入窘境的技术。
人类进行的科学技术研究，归根结底是为了造福于人类。
在科技发展的过程中，人类需要时刻修正科技发展的方向，修正科技成果应用的范围，使科技发展不偏离为人类服务的轨道中国书法艺术说课教案今天我要说课的题目是中国书法艺术，下面我将从教材分析、教学方法、教学过程、课堂评价四个方面对这堂课进行设计。
Unit3 Cloning 教案1. 知识目标：克隆的过程及其影响2. 技能目标：训练学生阅读技能，提高表达能力及语言运用技能3. 情感态度价值观：从道义和技术进步上对克隆有一个正确的认识克隆的内涵及其过程◆Step one ：Pre-reading（导入）See the video and ask the students “What are they talking about?” . Then show them two pictures , and ask them to distinguish natural clone and man-made clone to lead them to the new lesson。
As we know natural clone is easy,so this class we’ll mainly solve the questions about mand-made clone.(引入预习学案问题处理) Question：Can human cloning be beneficial to society? And why?（由学生表述思考结果）• Two different answers：1) Yes. Because one of the well-known benefits brought aboutby human cloning is medical advance .2) No. Because certain ambitious people would clone themselvesto attain their goals and carry on doing evil, which will makethe world in danger. （由此，引出文章的主题：多利羊的克隆过程及其出现所引发的问题，让学生带着问题理解课文。
Unit 2Cloning单元要览本单元的中心话题是“克隆”,即无性繁殖.1997年英国罗斯林研究所试验成功的克隆羊多莉是首次利用体细胞克隆成功的,它在生物工程史上揭开了新的一页.本单元具体内容涉及“什么是克隆”、“克隆羊多莉是如何诞生的”、“克隆的利与弊”等.通过本单元的教学,可以帮助同学们了解两种不同的克隆——自然克隆与人工克隆,克隆是如何产生的,人类从克隆中可以得到什么好处,克隆人可能带来什么问题,等等,同时可以引发他们对于克隆动物健康的关注以及对于克隆技术发展前景的思考等.Reading and Comprehending整体设计教学内容分析This is the first teaching period of this unit.The central part of this period is the reading passage with the name of Cloning：Where Is It Leading Us? It talks about what is cloning,the uses of cloning and different ideas about cloning.Warming Up gives four pictures to help students understand what is cloning and the types of cloning.Then they will be led to discuss which ones are natural clones and which ones are man-made,and think about how they differ.This part is designed to help the students to recall their background knowledge about cloning and prepares students for the whole unit.Pre-reading provides a table “Questions about cloning” and let students discuss what they understand about cloning.Then students can list the questions they want to find out and share their lists with one another.The aim of this part is for students to examine their concept of cloning and discuss what they know about the procedure to produce man-made ones.The aim of Reading is to introduce students to the procedure of animal cloning and the life of Dolly the sheep.It is a factual piece of writing.It explains some of the reasons why cloning is still controversial.Comprehending consists of three written or oral exercises for the students to do so as to help the students to get a better understanding of the text,that is to say,to help the teacher to check how much the students have understood the text.三维目标设计Knowledge and skills1．To know the meanings of the following new words and phrases in this period：differ（不同；相异）,exact（精确的,准确的）,twin（双胞胎之一）,commercial（商业的；贸易的）,straightforward（简单的；直接的；坦率的）,undertake（着手；从事；承担）,pay off （得到好结果；取得成功；偿清）,breakthrough（突破）,procedure（程序；步骤；手续）,carrier （携带者；搬运工；运输工具）,cast down（沮丧；不愉快）,altogether（总共；完全地）,arbitrary （任意的）,correction（改正；修正；纠正）,objection（不赞成；反对；异议）,medium/media （媒介；手段；工具）,obtain（获得；赢得）,attain（获得；到达）,moral（道德的；伦理的）,conservative（保守的；守旧的）,forbid（禁止；不准）,accumulate（积累；聚积）,in favour of（赞成；支持）2．To learn about some facts and views about cloning.3．To learn how the information is organized.4．To develop the students' reading ability by skimming and scanning the passage.5．To develop the students' speaking ability by talking about cloning.Process and methods1．While doing Warming Up the teacher can lead in the topic of this unit by showing students some pictures or videos about cloning,making the students recall their own knowledge about cloning.2．During Pre-reading the teacher can let students discuss the questions in groups.This discussion should be student-centered and lead them to the content of Reading.3．While doing Reading and Comprehending,the teacher may first ask the students to read the text quickly to get the general idea.After detailed reading of the passage,students are encouraged to discuss the writer's point of view.4．To consolidate the contents of the reading passage,the students should be required to retell the text in their own words at the end of the class.Emotion,attitude and value1．To make students realize the benefit of cloning and the harm of cloning.2．To develop students' sense of cooperative learning and competition.教学重点、难点1．To enable the students to learn about cloning and to develop their reading ability.2．To enable the students to talk about what we should do to deal with cloning properly.教学过程Step 1Warming upThe topic “cloning” is difficult for students.So the teacher should help the students learn more about it.In class the teacher can talk as follows.“Do you enjoy watching TV series？Have you ever seen Journey to the West？It tells howMonk Tang went to the Western Heaven to acquire scriptures.In this series,Monkey King plays an important part.He has seventy-two transformations.He can change his looks exactly the same as another one,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 clone Dolly the sheep appeared.Cloning technologies have been around much longer than Dolly,though.First things first,what is cloning？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 create d the muchcelebrated sheep “Dolly”,aroused worldwide interest and concern because of its scientific and ethical implications.Look at the pictures and discuss how natural clones and man made clones differ.”Step 2Pre-readingBefore class,ask the students to search for some information about cloning.Now show the questions on the screen,and then let them work in pairs and discuss about cloning.Ask the studentsfew minutes,ask students what is the writer's opinion about cloning.If they can't give their answers,ask them to read the article quickly to find answers to the questions.Suggested answers：1．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.2．This happens in plants when gardeners take cuttings from growing plants to make new ones and when small parts of a plant are taken and grown in a laboratory.It also happens in animals when twins identical in sex and appearance are produced from the same original egg.3．It can help cure disease and can help couples who can't bear a new baby.4．（1）People may want to clone themselves so they can live forever.（2）People may want to clone dead children.（3）People may want to clone their favourite pets.5．I do not think we should,for it may cause many moral problems.6．No.Because cloned human has the same quality as the real human while natural born baby's quality is higher than his parents.7．No.The cloned baby also has the disease.Step 3Reading and comprehendingGet the students to comprehend the passage quickly and accurately and meanwhile help the students form a good habit of reading.1．Fast readingShow the following questions on the screen.Ask students to read the passage quickly and tell2．Careful reading（1）Ask students to read the text again and find out the main idea of each paragraph.Paragraph 1：________________________________________Paragraph 2：________________________________________Paragraph 3：________________________________________Paragraph 4：________________________________________Paragraph 5：________________________________________Suggested answers：Paragraph 1：Cloning is a way of making an exact copy of another animal or plant.Paragraph 2：Cloning has two major uses.Paragraph 3：The problems of Dolly.Paragraph 4：The effect of Dolly.Paragraph 5：It is forbidden to clone human beings.（2）Show the following exercises on the screen and ask students to read the text again and find the answer to each question.①The main idea of the text is ______.A．animal cloning is very valuable and can benefit the worldB．animal cloning could be misused by bad people so it must be forbiddenC．animal cloning is well developed because Dolly the sheep was bornD．animal cloning raised arguments and scientists are not sure about its future②Which of the following statements about cloning is NOT true according to the text?A．Cloning is something that has been developed quite recently.B．Twins that look exactly the same are originally from the same egg.C．Cloning is used by gardeners to make more money.D．Animal cloning is much more difficult than plant cloning.③The lamb is the clone of the cell from sheep B because ______.A．it provides the egg cell B．it gives birth to the lambC．it provides the nucleus D．it is a female sheep④An original sheep most probably lives ______ years.A．3B．6 C．9D．13⑤Which of the following is NOT a problem or danger of cloning mentioned in the text?A．Evil leaders may want to clone themselves.B．Animal clones may develop the illness of older animals and may die younger than the donor animals.C．There are moral objections to cloning human beings.D．Too much cloning may lead to the destruction of the balance of nature.⑥Which 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．Famous persons who have passed away can be cloned.D．Cloning can help keep animals from becoming extinct.⑦We can infer from the last three paragraphs that ______.A．The normal development of Dolly had no effect on the cloning of other species.B．Dolly's serious disease and final death disturbed everyone in the world.C．Dolly successfully cloned a new lamb with the help of cloning scientists.D．There were arguments about animal cloning and concerns about the future of cloning.⑧What is the writer's attitude toward cloning in this passage?A．The writer is against cloning.B．The writer is in favour of cloning.C．The writer does not state any personal opinion about cloning.D．The writer is in agreement with cloning.Suggested answers：DACD DCDCStep 4Language studyDeal with language problems if any（words or sentences students might not understand）to help the students have a better understanding of the text.Step 5Listening,reading aloud and underliningAsk students to read the passage aloud to the tape and let them pay attention to the pronunciation of each word and the pauses within each sentence.Tell them to pick out all the useful expressions or collocations from the passage while reading and copy them down in their notebooks after class as homework.Collocations：quantities of,pay off,on the one hand,on the other hand,be appropriate to,have a great impact on,at present,etc.Step 6Homework1．Read the text carefully after class and learn the useful new words and expressions in this period by heart.2．Try to find some data about cloning on the Internet,and show your class in the next period and talk about them.Step 7Reflection after teaching________________________________________________________________________ ________________________________________________________________________教学参考Ⅰ．Cloning（克隆）Cloning in biology is the process of similar producing populations of genetically identical individuals that occurs in nature when organisms such as bacteria,insects or plants reproduce asexually.Cloning in biotechnology refers to processes used to create copies of DNA fragments （molecular cloning）,cells（cell cloning）,or organisms.The term also refers to the production of multiple copies of a product such as digital media or software.The term clone is derived f rom κλνοs,the Greek word for “trunk,branch”,referring to the process whereby a new plant can be created from a twig.In horticulture,the spelling clon was used until the twentieth century；the final e came into use t o indicate the vowel is a “long o” instea d of a “short o”．Since the term entered the popular lexicon in a more general context,the spelling clone has been used exclusively.Ⅱ．Molecular cloning（分子克隆）Molecular cloning refers to the process of making multiple copies of a defined DNA sequence.Cloning is frequently used to amplify DNA fragments containing whole genes,but it can also be used to amplify any DNA sequence such as promoters,non-coding sequences and randomly fragmented DNA.It is used in a wide array of biological experiments and practical applications ranging from genetic fingerprinting to large scale protein production.Occasionally,the term cloning is misleadingly used to refer to the identification of the chromosomal location of a gene associated with a particular phenotype of interest,such as in positional cloning.In practice,localization of the gene to a chromosome or genomic region does not necessarily enable one to isolate or amplify the relevant genomic sequence.To amplify any DNA sequence in a living organism,that sequence must be linked to an origin of replication,which is a sequence of DNA capable of directing the propagation of itself and any linked sequence.However,a number of other features are needed and a variety of specialized cloning vectors（small piece of DNA into which a foreign DNA fragment can be inserted）exist that allow protein expression,tagging,single stranded RNA and DNA production and a host of other manipulations.Cloning of any DNA fragment essentially involves four steps：1．fragmentation—breaking apart a strand of DNA2．ligation—gluing together pieces of DNA in a desired sequence3．transfection（转染）—inserting the newly formed pieces of DNA into cells4．screening/selection—selecting out the cells that were successfully transfected with the new DNAAlthough these steps are invariable among cloning procedures a number of alternative routes can be selected,these are summarized as a ‘cloning strategy’．Initially,the DNA of interest needs to be isolated to provide a DNA segment of suitable size.Subsequently,a ligation procedure is used where the amplified fragment is inserted into a vector（piece of DNA）．The vector（which is frequently circular）is linearised using restriction enzymes,and incubated with the fragment of interest under appropriate conditions with an enzyme called DNA ligase（连接酶）．Following ligation the vector with the insert of interest is transfected into cells.A number of alternative techniques are available,such as chemical sensitivation of cells,electroporation,optical injection and biolistics.Finally,the transfected cells are cultured.As the aforementioned procedures are of particularly low efficiency,there is a need to identify the cells that have been successfully transfected with the vector construct containing the desired insertion sequence in the required orientation.Modern cloning vectors include selectable antibiotic resistance markers,which allow only cells in which the vector has been transfected,to grow.Additionally,the cloning vectors may contain color selection markers,which provide blue/white screening on X-gal medium.Nevertheless,these selection steps do not absolutely guarantee that the DNA insert is present in the cells obtained.Further investigation of the resulting colonies must be required to confirm that cloning was successful.This may be accomplished by means of PCR,restriction fragment analysis and/or DNA sequencing.Ⅲ．Cloning in stem cell research（干细胞克隆研究）Somatic cell nuclear transfer,known as SCNT,can also be used to create embryos for research or therapeutic purposes.The most likely purpose for this is to produce embryos for use in stem cell research.This process is also called “research cloning” or “therapeutic cloning.” The goal is not to create cloned human beings（called “reproductive cloning”）,but rather to harvest stem cells that can be used to study human development and to potentially treat disease.While a clonal human blastocyst has been created,stem cell lines are yet to be isolated from a clonal source.Organism cloning（also called reproductive cloning）refers to the procedure of creating a new multicellular organism,genetically identical to another.In essence this form of cloning is an asexual method of reproduction,where fertilization or inter-gamete contact does not take place.Asexual reproduction is a naturally occurring phenomenon in many species,including most plants and some insects.Scientists have made some major achievements with cloning,including the asexual reproduction of sheep and cows.There is a lot of ethical debate over whether or not cloning should be used.However,cloning,or asexual propagation,has been common practice in the horticultural world for hundreds of years.Ⅳ．Dolly the Sheep（多莉羊）Dolly,a Finn-Dorset ewe,was the first mammal to have been successfully cloned from an adult cell.She was cloned at the Roslin Institute in Scotland and lived there from her birth in 1996 until her death in 2003 when she was six.Her stuffed remains were placed at Edinburgh's Royal Museum,part of the National Museums of Scotland.Dolly was publicly significant because the effort showed that the genetic material from a specific adult cell,programmed to express only a distinct subset of its genes,can be reprogrammed to grow an entire new organism.Before this demonstration,it had been shown by John Gurdon that nuclei from differentiated cells could give rise to an entire organism after transplantation into an enucleated egg.However,this concept was not yet demonstrated in a mammalian system.Cloning Dolly the sheep had a low success rate per fertilized egg；she was born after 237 eggs were used to create 29 embryos,which only produced three lambs at birth,only one of which lived.Seventy calves have been created and one third of them died young；Prometea took 277 attempts.Notably,although the first clones were frogs,no adult cloned frog has yet been produced from a somatic adult nucleus donor cell.There were early claims that Dolly the Sheep had pathologies resembling accelerated aging.Scientists speculated that Dolly's death in 2003 was related to the shortening of telomeres,DNA-protein complexes that protect the end of linear chromosomes.However,other researchers,including Ian Wilmut who led the team that successfully cloned Dolly,argue that Dolly's early death due to respiratory infection was unrelated to deficiencies with the cloning process.Though Dolly was the first cloned mammal,the first vertebrate to be cloned was a tadpole in 1952.Ⅴ．Ethical issues of cloning（克隆引起的伦理问题）Although the practice of cloning organisms has been widespread for several thousands of years in the form of horticultural cloning,the recent technological advancements that have allowed for cloning of animals（and potentially humans）have been highly controversial.The Catholic Church and many religious organizations oppose all forms of cloning,on the grounds that life begins at conception.Conversely,Judaism does not equate life with conception and,though some question the wisdom of cloning,Orthodox rabbis generally find no firm reason in Jewish law and ethics to object to cloning.From the standpoint of classical liberalism,concerns also exist regarding the protection of the identity of the individual and the right to protect one's genetic identity.Gregory Stock is a scientist and outspoken critic against restrictions on cloning research.Bioethicist Gregory Pence also attacks the idea of criminalizing attempts to clone humans.The social implications of an artificial human production scheme were famously explored in Aldous Huxley's novel Brave New World.On December 28,2006,the U．S.Food and Drug Administration（FDA）approved the consumption of meat and other products from cloned animals.Cloned-animal products were said to be virtually indistinguishable from the non-cloned animals.Furthermore,companies would not be required to provide labels informing the consumer that the meat comes from a cloned animal.Critics have raised objections to the FDA's approval of cloned-animal products for human consumption,arguing that the FDA's research was inadequate,inappropriately limited,and of questionable scientific validity.Several consumer-advocate groups are working to encourage a tracking program that would allow consumers to become more aware of cloned-animal products within their food.Joseph Mendelson,legal director of the Center for Food Safety,said that cloned food still should be labeled since safety and ethical issues about it remain questionable.Carol Tucker Foreman,director of food policy at the Consumer Federation of America,stated that FDA does not consider the fact that the results of some studies revealed that cloned animals have increased rates of mortality and deformity at birth.（以上材料均来源于：/wiki/Cloning）。
话题语言应用——克隆编稿：牛新阁审稿：王春霞语言积累交际用语1．接受与拒绝I’m happy to accept... but.... 我很高兴接受......，但是......I can / cannot accept your argument because... 我能/不能接受你的说法，因为......I support... because...我支持......因为......No, I can’t agree with... because... 不，我不同意...... 因为......I agree with / could never agree to... because... 我同意/永远也不同意......因为......How can you believe that? 你怎么能相信那事呢？Your argument has convinced me because... 你的理由说服了我，因为......I would like to agree with you but... 我想同意你的看法，但是......Do you think it is wise to...? 你认为做......明智吗？No, that is not reasonable because... 不，那不合理，因为......Is it fair to...? 做......公平吗？I don’t care for your ideas because... 我不接受你的观点，因为.....I don’t mind but... 我不介意，但是......2．表扬与鼓励Your ideas sound very encouraging to me．你的观点在我看来很鼓舞人心。
That’s a good / great idea．好主意。
Well done to you for... 做得好......话题语句（1）有关克隆：1. What’s cloning? Cloning is a way of making an exact copy of another animal or plant.2. 两种克隆：man-made clones 人工克隆natural clones 自然克隆3. How a clone is produced?The cloning of plants is simple and relatively easy. It can be done by taking cuttings (man-made cloning) or letting the plant produce its own runners (natural cloning). The cloning of animals is more complicated. It was not achieved until 1996.4. Dolly the sheep was the first successful clone of a mammal（哺乳动物）.5. Animal cloning raised arguments and scientists are not sure about its future.要点提示：relatively 相对来说cutting 插枝runner 蔓，纤匐枝complicated 结构复杂的Clone an extinct animal？克隆灭绝动物？1. Why shouldn’t you clone an extinct animal unless there is enough diversity in the group? There will not be enough genetic variation in the group to be able to resist new illnesses.2. Why is it wrong to clone an extinct animal if it would have to live in a zoo?It is not a good idea to clone an animal that would have to live in a zoo because it is not a suitable habitat to develop and increase its numbers. The zoo is not a natural environment for a wild animal.3. Why can’t you clone the DNA of animals that have been extinct longer than 10,000 years?The DNA of animals more than 10,000 years old is not suitable for cloning, for it can’t survive so long.要点提示：extinct 灭绝的diversity 多样性variation 变化（vary v. 变化）habitat 栖息地survive 幸存Questions to discuss:1.Do you support the idea of producing human embryos (胚胎) for medical purposes? Why?2.Do you think it a good idea to use cloned humans for organ transplants? Why?3.Do you think a cloned human should have human rights? Why?4.Do you think cloned humans will have the same talents as the original ones? Why?要点提示：for medical purposes 为了医用目的organ transplants 器官移植cloned humans 克隆人human rights 人权original 原来的，起初的话题语句（2）Advantages and disadvantages of cloningAdvantages1. to produce commercial quantities of plants2. be useful for research on new plant species3. be useful for research on animals.4. to help cure serious illnesses in humans.Disadvantages1. may develop the illnesses of older animals.2. may die younger than the donor animals.3. Evil leaders may want to clone themselves to attain their ambitions.may be misused by bad people4. may cause some moral and religious problems.要点提示：commercial 商业的species 物种donor 捐赠者，供体evil 邪恶的moral 道德上的religious 宗教的Two reasons for/against medical cloningFor：1. to cure serious illnesses that have no cure at the moment2. to help people who have diseases which make them gradually lose their ability to move easily or to thinkAgainst：1. to make the stem cells that will cure an illness of one person, you have to kill another human being2. Scientists are worried about the efficiency (效率) of the system.Attitude towards cloning：positive肯定的negative否定的neutral中立的objective客观的, impartial 公平的arbitrary武断的optimistic乐观的pessimistic悲观的critical持批评态度的cautious谨慎的indifferent冷漠的subjective 主观的【高清课堂：Cloning 语言应用】话题语句（3）About cloning 有关克隆1. IntroductionThe 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 (伦理的) implications. The feat（功绩）, cited by Science magazine as the breakthrough of 1997, also generated uncertainty over the meaning of “cloning”—an umbrella （庇护）term traditionally used by scientists to describe different processes for duplicating biological material.注释：cite 引用，嘉奖generate 产生duplicate 复制biological（biology）生物的2. What is cloning?When the media report on cloning in the news, they are usually talking about only one type called reproductive (复制) cloning. There are different types of cloning however, and cloning technologies can be used for other purposes besides producing the genetic twin of another organism（有机体）.注释：genetic 遗传（学）的3. Are there different types of cloning?A basic understanding of the different types of cloning is key to taking an stance (立场) on current public policy issues (议题) and making the best possible personal decisions. The following three types of cloning technologies will be discussed: (1) recombinant (重组器官) DNA technology or DNA cloning, (2) reproductive cloning, and (3) therapeutic (治疗的) cloning.4. Can organs be cloned for use in transplants移植?How would you like a clone of yourself stowed (储藏) away somewhere in case you need a new heart or liver, like a spare tire in the trunk of a car? Organ transplants are difficult undertakings for two major reasons. First, you have to find a donor（捐赠人）, and second, there’s no guarantee that your body will accept the new organ. Statistically, organ demand far outweighs current supply. What if you cloned organs from your own cells that your body would recognize? But the question is how cloned organ transplants would work? If you wanted to keep living, doctors obviously couldn’t remove your heart and clone a new one. Cloning yourself in order to use the clone’s organs wouldn’t fly either.注释：spare tire 备胎organ transplants 器官移植outweigh （在重量、重要性或价值方面）超过5. What are the risks of cloning?Reproductive cloning is expensive and highly inefficient (无效率的). More than 90% of cloning attempts fail. In addition to low success rates, cloned animals tend to have higher rates of infection, tumor (肿瘤) growth, and other disorders. Japanese studies have shown that cloned mice live in poor health and die early. About a third of the cloned calves (小牛) born alive have died young, and many of them were abnormally large. Appearing healthy at a young age unfortunately is not a good indicator (指示物) of long-term survival. Clones have been known to die mysteriously. ■话题语句（4）有用的句子----- 试试你会了吗？1. 克隆植物比较简单，然而克隆动物就非常复杂了。
