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Unit Eight Cloning
What is cloning? • Cloning is the process of making a genetically identical organism through nonsexual means. • In genetic engineering, cloning refers to the copying of DNA molecules.
Cloning Milestones • 1938 Cloning is envisioned. Hans Spemann proposed • • what he called a "fantastical experiment. " He suggested taking the nucleus from a cell of a late-stage embryo and transplanting it into an egg. In other words, cloning. 1952 First cloning experiment with frogs. Robert Briggs and T. J. King used a pipette to suck the nucleus from the cell of an advanced frog embryo and added it to a frog egg. It did not develop. 1984 First embryo cloning with sheep is reported. Steen Willadsen reported that he cloned a live lamb from immature sheep embryo cells. Others later replicate his experiment using a variety of animals, including cattle, pigs, goats, rabbits and rhesus monkeys.
• 1994 First cloning of more advanced embryo cells. Neal First cloned calves from embryos that have grown to at least 120 cells. • 1996 Dr. Ian Wilmut and his team clone the world's the first sheep from adult cells. The lamb born in July 1996 is named Dolly.
• 1997 A team led by Drs. Ian Wilmut and Keith Campbell (U. K. ) create the first sheep with a human gene in every cell of its body. The genetically engineered lamb is named Polly.
• 2000 Japanese scientists clone a baby bull from a bull that was a clone itself, the first re-cloning case involving a large mammal. • 2002 A team of scientists at Texas A&M University produces the first cloned pet, a calico kitten called “CC” (for Copy Cat). The work was funded by Arizona millionaire John Sperling, whose company, Genetic Savings and Clone, hopes to clone pets for profit.
China’s Breakthroughs in Cloning • 1999 Chinese scientists have produced an • embryo of a giant panda through cloning technology, a breakthrough that could save the endangered animal. scientists from the Chinese Academy of Sciences had introduced cells of a dead female panda into the egg cells of a Japanese white rabbit and the embryo was nurtured successfully. 2003 Chinese scientists have produced human embryonic stem cells by mixing human skin with rabbit eggs. This experiment would represent the first time human embryonic stem cells had been generated via cloning.
• Human cloning is a very controversial issue and there are many advantages and disadvantages.
Major Advantages of human Cloning • One advantage would be the issue of talents and that some of them seem to be influenced genetically, such as musical ability. Cloning using the DNA from an adult who is musically talented could result in a cloned child growing up to be equally talented. (continued)
• In the case where a husband is sterile and can not produce a child sexually he could contribute a cell from his body and through this type of cloning the wife and husband could both contribute to a cloned child, where the wife would provide the so called factory for raising the baby while the husband would provide the genetic information. This could be a viable option instead of using sperm from another man. A similar situation might be if two women would like to have a child together. They could use this cloning technique instead of going the way of artificial insemination.
Major Disadvantages of Human Cloning • there is a high chance that the clone will not be • normal. It may have some disorder; either starting at birth or the clone may get a disorder or disease related to the cloning process later in life. There is also the issue of the cells aging. Cells are believed to have a set life span and that using an aged cell of say an adult human would result in the cloned child starting off with cells already aged thus having an effect on that child’s life span.
• Another problem is that • after the technique of using a female egg and a female cell to make a clone there would really be no genetic need for men. Another issue is diversity; if cloning is done large scale genetic diversity could be depleted. Diversity is really what the human race is all about, so this could be a disaster.
• A huge case against human cloning is the • emotional effects on the clone, for example a cloned child would in effect be a twin of one of his parents which could lead to serious emotional difficulties. There is also the religious side of things. For example, whether or not removing the nucleus is murder or whether or not the cloned human would have a soul. Some religious people believe that the soul enters the body when a sperm fertilizes an egg, but since sperm is not used during the reproductive cloning process there may not be a soul present, which gets into some pretty deep controversy.
Text A A Clone Is Born
Text Organization • Part One (Paras 1 -2) Dolly the sheep, a clone, was born.
• Part Two (Paras 3 -6) Dolly’s birth has made cloning a reality and human cloning a possibility.
• Part Three (Paras 7 -11) People have to face the ethical problems of human cloning. This part can be further divided into…
Section One (Paras 7 -9): Human cloning has given rise to the question of what implications the technology may have for mankind. Section Two (Paras 10 -11): The making of the atomic bomb had a tremendous impact on scientists.
• Part Four (Paras 12 -16) Cloning technology could benefit people in more than one way.
Cultural Notes • Narcissus • Prometheus • Oppenheimer, (Julius) Robert • Hiroshima • Nagasaki
Language Points • give birth to: produce young; bring about The cat gave birth to five kittens. This issue gave birth to a dispute. • for all the world like sth. / sb. /as if: very much or exactly like someone or something or as if… She carried on with her work for all the world as if nothing had happened.
• fuse: join sth. or become joined by means of heat In her richest work she fuses comedy and tragedy. • residence: process of residing; place in which one lives Residence among the poor is suggested as a way of understanding their problems. Downing Street is the British Prime Minister’s official residence.
• identical (to / with): exactly alike; the same On Monday, the pupils wear identical school uniforms. cp. identify & indentity identify (with): consider as identical or united We shouldn’t identify happiness with wealth. identity: the set of behavioral or personal characteristics This check will be cashed on proof of identity.
• in principle: as far as basic principles are concerned; in general but not in detail Though there is no reason in principle why women cannot be top leaders, they work in reality under men more often than not. They have agreed to the proposal in principle but we still have to negotiate the terms.
• offensive: upsetting or annoying; disgusting or repulsive Why did he make such offensive remarks at the meeting? An offensive smell greeted my nose when I opened the door. cp. offend: cause displeasure; violate a rule or law Some music offends, rather than pleases, the ear.
• compromise: n. giving up of certain demands by each side in a dispute, so that an agreement may be reached which satisfied both; v. settle a dispute by making compromise (on / over) The NATO countries have finally reached a compromise over whether the US-led multinational troops are justified in launching attacks against Iraq. I want to go Greece, and my wife wants to go to Spain, so we compromise on Italy.
• let loose: release When we escape, shall we let loose other prisoners? Just close your eyes and let loose your imagination. • deadly: causing or likely to cause death deadly weapons cp. deathly: like or suggesting death The whole village was shrouded in deathly silence.
• lash out at: make a sudden violent attack on with blows or words He lashed out at the ruling party’s foreign policies. • start out: intend when starting; begin (a journey) They started out to want a house, but eventually bought a flat. With the help of the Spanish king, he started out his journey across the Atlantic Ocean.