First, the overall grasp
The article "Wonderful Clone" uses four subheadings to make the full text clear and coherent. A glance at the subtitle of the text will give you a general idea of the content of the text.
What is a human clone? Cloning is a new biotechnology of asexual reproduction. In the section "What is cloning", the author makes this science and technology easy to understand. First of all, from the common biological phenomena that we can easily understand, "a bacterium can be divided into two in about 20 minutes; When a grape branch is cut into ten segments, it may become ten grapes ... all these are creatures that reproduce by splitting themselves in two or expanding a small part of themselves. This is asexual reproduction. "In this way, advanced science and technology is vivid and clear. Then, tracing the original intention of "cloning" from the etymology, let us further understand the meaning of cloning. Following the last article, the article further introduces cloning, from plant "cloning" to animal "cloning". With the conclusion that "the Monkey King often pulls out a handful of monkey hair at a critical moment and turns it into a large group of monkeys, and the monkey hair turns into a monkey is a cloned monkey", the science and technology writing is very interesting.
2. Clone crucian carp before and after birth. This section is a brief introduction and explanation of cloning experiment. In this section, the author does not write cloning experiments in chronological order, but uses two clues to organize the materials: one is to highlight the research achievements and contributions of China scientists in cloning experiments based on Chinese and foreign scientific experiments; One is to arrange materials according to the experimental objects, namely fish, amphibians and mammals. This writing is easy to understand the development of cloning technology. The organic combination of the two clues greatly enhances the interpretation effect.
3. Clone the sheep Dolly. This section describes the birth process of Dolly in detail, revealing the great significance and great response of the success of cloned sheep.
4. Cloning technology benefits mankind. This section writes that "cloning technology will bring great benefits to mankind" from three aspects: first, cloning can effectively breed high value-added livestock; Second, cloning can be used to save rare animals; Third, cloning is of great significance to the prevention and treatment of human diseases and the extension of life span. However, the author is not immersed in blind optimism, but puts forward a cold reflection on cloning involving moral and ethical issues.
This paper first writes about the significance of cloning, then writes about cloning experiments, then writes about the development of cloning, and finally writes about the benefits that cloning brings to human beings and the thinking of cloning. The context of writing is very clear, indicating that things are progressing step by step.
Second, the problem research
This article has its own characteristics in writing, which can be discussed from the following aspects. First of all, in the structural arrangement of the article, the full text is divided into four parts and four subheadings. These four parts explain cloning from different aspects, but there is a close logical connection before and after. Secondly, the paper uses a variety of interpretation methods to explain the difficult scientific truth in simple terms. Thirdly, the author's thoughts and feelings are soaked in the text, from which students not only gain scientific knowledge, but also receive education and enlightenment.
Practice note
Read the text quickly and answer the following questions.
1. What explanations does the author use to explain "what is cloning"?
2. What is the explanation order of the section "Cloned crucian carp before and after birth"? Why not write "Cloning Experiment" in chronological order? What are the advantages of this arrangement in this article?
3. Why did the birth of "cloned sheep" cause a "sensation" in the world?
4. In what ways does the text say that cloning technology benefits mankind?
This topic aims to help students master the text as a whole. On this basis, understand the order and method of explaining the text.
1. In order to explain "cloning", the author uses three methods: example, explanation and quotation. Examples: cite familiar examples from plants and animals to make difficult scientific knowledge easy to understand; Interpretation: trace the source of the word cloning and explain it; Quotations: The story of the Monkey King pulling out a handful of monkey hair and turning it into a large group of monkeys introduced in The Journey to the West vividly illustrates what cloning is all about.
2. The section "Before and after the birth of cloned crucian carp" shows that the arrangement of order reflects the author's writing skills. There are two clues in this section: first, from the "cloning experiment" in China to the "cloning experiment" abroad, which highlights the achievements and contributions of scientists in China in cloning research; Second, writing about "cloning experiments" from fish, amphibians to mammals shows that scientists' pursuit of science is endless and a process of continuous exploration. At the same time, it also provided a scientific basis for the birth of "Dolly the Cloned Sheep" and paved the way for writing.
3. The birth of cloned sheep caused a sensation all over the world, mainly for two reasons: firstly, it marked the new progress and major breakthrough in cloning research, and "this result proved that the so-called highly differentiated cells with specific morphology in animals have the same potential as fertilized eggs to develop into complete individuals. In other words, animal cells are as totipotent as plant cells. " Second, it may be the gospel of mankind, but it may also be a bad omen for mankind, that is to say, it can not only benefit mankind, but also cause harm to mankind.
4. The text is mainly written from three aspects: cloning technology benefits mankind. First, cloning can effectively breed "high value-added livestock"; Second, cloning can be used to save rare animals; Third, cloning is of great significance to the prevention and treatment of human diseases and the extension of life span.
Second, find out the sentences that can express the rigorous, realistic and persistent attitude and spirit of scientists from the text.
The design of this exercise is mainly to let students experience and learn the rigorous, realistic and persistent attitude and spirit of scientists in the process of scrutinizing language and writing. For example:
(1) "Artificial culture of crucian carp blastocyst cells. After continuous subculture for 385 days and 59 generations, the nucleus was sucked out of the cultured cells with a glass tube with a diameter of about 10 micron under the microscope. "
(2) "1,out of 89 eggs, only two fry hatched, and finally only one young fish survived the difficulties, and after more than 80 days of cultivation, it grew into an 8 cm long crucian carp."
(3) "... take out the nuclei from the intestinal epithelial cells, liver cells and kidney cells of Xenopus tadpoles by superb surgery, and accurately put the nuclei of these cells into the eggs whose nuclei have been destroyed by ultraviolet rays. "
(4) "After hundreds of gray, black and white operations, the white mouse finally gave birth to three gray mice."
(5) "After 247 failures, they got a cloned ewe named Dolly in July 1996."
(6) "... take out the nucleus from the egg cell with a very thin straw. ..... immediately injected into the enucleated "Scottish black sheep" egg cells. ..... Then, the embryo is skillfully implanted into the uterus of another ewe. "
Third, the article writes: "The discussion about' human cloning' reminds people that scientific and technological progress is a March of sadness and joy. The more science and technology develop, the wider and deeper it penetrates into society, and the more likely it is to cause many related ethical, moral and legal problems. " Talk about your understanding of this passage.
This question can be discussed and there is no unified answer; You can also carry out Chinese activities in combination with the content of "Comprehensive Learning" in this unit-"Debate on Cloning". Teachers should guide students to consult articles about cloning, and can also recommend articles about cloning for students to discuss. The discussion on this issue can generally be carried out from the following aspects: 1. Science is a double-edged sword, which can benefit and harm human beings. The degree of benefit and harm of science is increasing simultaneously, such as the discovery and utilization of nuclear. 2. The development of science is getting closer and closer to human beings from nature, and it touches human ethics, morality, law and human mind more and more deeply, such as human cloning; 3. Scientific development will also lead to the change and renewal of human morality and ethics. How to establish and improve the ethical values of modern society, so that it can not only guide the development of science and technology, but also adapt to the progress of science and technology, rationally and morally benefit mankind with the sword of science, and at the same time let mankind really enjoy and appreciate the happiness brought by science, which will be a problem that modern society must explore and face.
[Edit this paragraph] Related information
Cloning is a transliteration of the English word "clone" or "clone", and the English word "clone" comes from the Greek word "Klone", which originally meant to cultivate plants through asexual or vegetative propagation, such as stem cutting and grafting. Today's cloning refers to the asexual reproduction of organisms through somatic cells and the population of offspring individuals with exactly the same genotype formed through asexual reproduction. Cloning can also be understood as copying, copying, that is, producing the same copy from the prototype, and its appearance and genetic genes are exactly the same as the prototype. Today, the meaning of "cloning" is not only "asexual reproduction", but also refers to a group of individuals from the same ancestor who reproduce asexually. This group of asexual offspring from the same ancestor is also called "asexual cloning", which is called cloning for short. Simply put, it is an artificially induced asexual reproduction method. But cloning is different from asexual reproduction. Asexual reproduction means that there is no combination of male and female germ cells, and only one kind of organism produces offspring. The common reproduction methods are spore reproduction, budding reproduction and fission reproduction. It is also called asexual reproduction to produce new individuals by layering or grafting the roots, stems and leaves of plants. Sheep, monkeys, cows and other animals cannot reproduce asexually without manual operation. Dolly the cloned sheep is also the product of cloning. Scientists call the process of artificial gene manipulating animal reproduction cloning, and this biotechnology is called cloning technology. About the idea of cloning, Wu Cheng'en, a great writer in Ming Dynasty, had a wonderful description-the Monkey King often pulled out a handful of monkey hair at a critical moment and turned it into a large group of monkeys, and the monkey hair turned into a monkey is a cloned monkey.
It is a transliteration of the English word "clone", which is translated as "asexual reproduction" in Chinese mainland and generally translated as copy or transfer in Taiwan, Hong Kong and Macao. It is a process of using biotechnology to produce offspring that are exactly the same as the original individual genome. Scientists call the process of artificial gene manipulating animal reproduction cloning, and this biotechnology is called cloning technology. Cloning technology itself is asexual reproduction, that is, a pure cell line formed by the division and reproduction of the same ancestor cells, and the genes of each cell in this cell line are identical to each other.
Another cloning method is to extract two or more human gene cells and combine them to form an embryo. After birth, cloned people will have the characteristics of several people who provide genes. Just like the clone 47 ~+07 (ultimate assassin code 47) in the game, the protagonist killer 47 is a clone. His genes come from a combination of five people.
[Edit this paragraph] Basic process
Firstly, the nucleus of a donor cell containing genetic material is transplanted into an egg cell without nucleus, and then the two cells are fused into one by micro-current stimulation, and then the new cell is promoted to divide and reproduce and develop into an embryo. When the embryo develops to a certain extent, it is implanted into the uterus of an animal to make the animal pregnant, so that an animal with the same gene as the cell donor can be born. In this process, if the donor cells are genetically modified, the genes of the offspring of asexual animals will also change in the same way.
Cloning technology does not require male and female mating, and does not require the combination of sperm and eggs. It only needs to extract single cells from animals, cultivate them into embryos by artificial methods, and then implant the embryos into female animals to breed new individuals. This cloned animal cultured with single cells has exactly the same characteristics as the single-cell donor and is a "replica" of the single-cell donor. Scientists in Britain and Oregon in the United States have successively cultivated "cloned sheep" and "cloned monkeys". The success of cloning technology is called "historic event and scientific innovation". Some people even think that cloning technology can be compared with the advent of the atomic bomb that year.
Cloning technology can be used to produce "cloned human" and "cloned human", which has aroused widespread concern all over the world. Is cloning sad or happy, a curse or a blessing for human beings? Materialist dialectics holds that everything in the world is a contradictory unity, which is divided into two parts. So is cloning technology. If we use cloning technology to "copy" a war madman like Hitler, what will it bring to human society? Even if it is used to "copy" ordinary people, it will bring a series of ethical problems. If cloning technology is applied to animal husbandry production, it will make fundamental changes in the cultivation and reproduction of excellent livestock breeds. If cloning technology is used in the research of gene therapy, it is very possible to overcome the persistent diseases that endanger human life and health, such as cancer and AIDS. Cloning technology, like atomic energy technology, is a double-edged sword with the hilt in human hands. Human beings should take joint action to avoid the emergence of "human cloning" and let cloning technology benefit human society.
[Edit this paragraph] Tan Jiazhen
Tan (1909-2008), an international geneticist, the founder of modern genetics in China, an outstanding scientist and educator. People from Ningbo, Zhejiang. 1September, 909 15 was born in a family of postal clerks in Cicheng, Cixi County, Ningbo City, Zhejiang Province. /kloc-0 graduated from high school in July, 926, and was recommended to Soochow University in Suzhou, majoring in biology. /kloc-0 was recommended to study for a master's degree in yenching university in August, 1930, and studied under Professor Li Ruqi. /kloc-0 returned to Soochow university to teach in February, 932. 1September, 934 to1July, 937, he went to California Institute of Technology to study for a doctorate, and studied under Morgan, the founder of modern genetics, and his assistant Dubzhansky. During my work in the United States, I was engaged in the evolutionary genetics research of Drosophila. I used the latest method to study the salivary gland chromosomes of Drosophila at that time to analyze the chromosome differences and genetic maps of related species of Drosophila, which promoted the formation of "modern comprehensive evolution theory". He has published more than 0 papers 10 independently or in cooperation with American and German scientists. 1946 found the dominant genetic phenomenon of mottle inlay in harmonia axyridis, which attracted the attention of the international genetics community. 1In August, 937, he gave up the generous treatment abroad and resolutely returned to China, where he was employed as a professor in the Biology Department of Zhejiang University. 195 1 year as dean of the school of science, Zhejiang university.
1952 after the adjustment of the department, he served as the head of the biology department of Fudan University. 1961April to present Vice President of Fudan University. Fudan University established the first genetics major, the first genetics research institute and the first school of life sciences. 1978, initiated and served as the vice president, president and honorary president of China Genetic Society, editor-in-chief of Genetics magazine, chairman of China Environmental Mutant Society and president of China Bioengineering Society. From 65438 to 0983, he served as a consultant of Fudan University and was elected as a member of the Standing Committee of the Fifth and Sixth CPPCC and vice chairman of the NLD. 1980 was elected member and academician of biology department of China Academy of Sciences. Tan has been engaged in education for decades and has trained a large number of scientific and technological talents. He also widely participated in various social activities and held various positions. Mainly the chairman of the Chinese Genetic Society and the vice chairman of the 15th International Genetic Society (1980). Curator of Shanghai Natural Museum, deputy director of the Standing Committee of Shanghai Municipal People's Congress, the 6th Standing Committee of China People's Political Consultative Conference, vice chairman of the 5th Central Committee of China Democratic League and chairman of the 8th Shanghai Democratic League. 1985 won the Outstanding Scientist Award of Qiushi Science Foundation. On September 28th, 1993, an expert group headed by Professor Tan, organized by the Life Science Department of the National Natural Science Foundation of China, demonstrated and passed the major project "Study on Gene Structure of Several Sites in China Genome" applied by Professor Qiang Boqin and researchers in Shanghai, and announced the official start of human genome research in China. In 2000, he was awarded the title of "the first educational hero in Shanghai". 2008 1 65438+1October1died in Shanghai Huadong Hospital at 7: 08 am at the age of 100.
Tan has made great contributions to the development of genetics in China, especially in the research on the evolution of genetic structure of Drosophila population and the genetic variation of Harmonia axyridis strains, which provides important arguments for the establishment of modern evolutionary synthesis theory. Tan has been engaged in genetics teaching and research for 70 years, and has successively taught general biology, comparative anatomy of vertebrates, embryology, genetics, cytology, advanced experimental chemistry, cytogenetics, Darwinism, radiation genetics, protozoology and other courses. He has published more than 100 research papers and academic articles, mainly including Selected Tan Papers (1987, Science Press) and Tan Wenxuan (1992, Zhejiang Science and Technology Press). His research work mainly involves cytogenetics, population genetics, radiation genetics, toxicology genetics, molecular genetics and genetic engineering of ladybugs, fruit flies, macaques, humans and plants. In particular, pioneering achievements have been made in the field of population evolution of Drosophila melanogaster and genetic variation of Harmonia axyridis spots, which provides important arguments for laying a modern comprehensive evolution theory. During his teaching in Zhejiang University, he discovered the mosaic dominance phenomenon of ladybug stain inheritance. It has aroused great response from the international genetics community and is considered as a great contribution to the development of classical genetics. Mr. Tan insisted on scientific truth and devoted his life to genetics. He trained a large number of outstanding talents for genetic research; Established the first genetics major, the first genetics research institute and the first life science academy in China.
Cloning human beings violates human bioethics (Qiu Deqing, Jiang Shiliang)
Should modern science and technology, especially modern life science and technology, respect ethical principles and listen to ethical voices? Experts point out that some scientific lunatics secretly clone human beings in the United States-cloning human beings violates human life ethics.
Recently, many domestic media reprinted an amazing news reported by foreign media: a group of scientific lunatics manipulated by cult organizations are conducting a secret human cloning experiment in the depths of the desert in Nevada, USA. According to the same principle that British scientists created Dolly, the world's first cloned sheep, they extracted cells from an American baby girl who died in February this year, and made clones. It is said that "if all goes well, the world's first clone will be born at the end of next year."
After the news was disclosed, cloning technology and its ethical issues once again became a hot topic of discussion. If this news is true, how to treat this matter and how to correctly evaluate and think about this issue, the reporter visited the director of the Ethics, Law and Society Department of the Southern Research Center of the National Human Genome and researcher Shen Mingxian of the Institute of Philosophy of the Shanghai Academy of Social Sciences.
Professor Shen said: Since Dolly sheep was successfully cloned by Roslin Institute in England in 1997, driven by fame and fortune, people abroad have been proposing and trying to engage in human cloning research. Although governments have banned it, reports related to human cloning have appeared in newspapers more than once in the past two years. However, it is really shocking that this time the speed is so fast and it is related to cult organizations.
It is understandable that parents who have lost their beloved daughter hope to revive their daughter through cloning technology. But if scientists use this to carry out experiments on human cloning, it is worth discussing. Professor Shen believes that even if cults are abandoned, this practice is not desirable. As far as "human cloning" is concerned, he will live in the shadow of "I am a replica of the dead". How will this affect his psychology?
According to the viewpoint of bioethics, science and technology should proceed from long-term interests and benefit all mankind. It must follow the four internationally recognized ethical principles of "doing good, not hurting, independence and justice". Dolly's sheep cloning has successfully experienced more than 200 failures, and there have been deformed or aborted sheep. However, human cloning is more complicated and will undoubtedly encounter more failures. If unhealthy, deformed and short-lived people are created, it is a violation of human rights.
The diversity of human genes is the biological basis of human evolution, and the so-called "immortality" that those scientific lunatics want to create is actually a copy of the same gene, which may reduce the diversity of genes and is not conducive to human evolution. Therefore, we should resolutely oppose human cloning from the perspectives of individuals, the whole, social evolution and bioethics.
Professor Shen pointed out that at present, the scientific community divides cloning into therapeutic cloning and reproductive cloning. The former uses embryonic stem cells to clone human organs for medical research to solve the problem of insufficient donors for organ transplantation, which is supported by the international scientific and ethical circles, but there is a premise that the embryos used for therapeutic cloning cannot exceed the limit of pregnancy 14 days. As for reproductive cloning, that is, human cloning, on the whole, it violates the principles of bioethics, so the mainstream opinion of scientists is firmly opposed. UNESCO, the World Health Organization, the International Human Genome Ethics Committee and governments all expressed their opposition to reproductive cloning very clearly. Even if human cloning is really born, we still have to stick to this basic position.
Modern science and technology is a double-edged sword, which will bring some negative effects while benefiting mankind. This raises a question for us: should modern science and technology, especially modern life science and technology, respect ethical principles or listen to ethical voices? Professor Shen pointed out: Now some scientists suggest that it should be done as long as it is scientifically possible. Actually, this is a wrong view. If technically we can create super life that seriously harms human beings, can we also create it? Some scientific lunatics are doing things that are harmful to mankind under the banner of "scientific freedom". Therefore, we should be wary of modern science and technology being used by some people with ulterior motives. In addition, the freedom of science and ethics cannot be opposed. The fact of the development of modern life science shows that the standardization and guidance of ethics does not restrict the development of science. Listening to the voice of ethics is conducive to the healthy and smooth development of science.