英语听力:自然百科 探索世界奥秘之The Ghost In Your Genes(基因外遗传现象) Unit03(在线收听) |
探索世界奥秘之The Ghost In Your Genes(基因外遗传现象) Unit03 Named after Henry Angelman, the pediatrician who first described Angelman syndrome. He referred to them as happy puppet children because it described, to some extent, the features. They have a rather jerky sort of movement when they are walking. These children have no speech. They are severely incapacitated in terms of learning, but are uncharacteristically happy as they are smiling all the time. The condition was caused by a genetic fault: a key sequence of DNA was missing, deleted from Chromosome 15. Then we came across a paradox: at the same time, er, the same change, the same little deletion of Chromosome 15 had been clearly associated with a quite different syndrome, much milder in terms of, er, of intellectual impairment, the Prader-Willi syndrome. These children are characterized by being very floppy at birth, but once they started eating properly and so on, they then had an insatiable appetite and would get very, very large. What Pembrey saw simply made no sense. Here were two completely different diseases, Angelman syndrome and Prader-Willi syndrome being caused by exactly the same genetic fault. So here we're in a bizarre situation really, how could we have proposed that the same deletion could cause a, a different syndrome? It appeared to Pembrey as if the simple view of inheritance was beginning to unravel, but his doubts were contrary to the tide of optimism sweeping the scientific community. In the early 1990s, the biggest project ever undertaken in biology was captivating the world. The Human Genome Project will be seen as the outstanding achievement in the history of mankind. The Human Genome Project was to be the pinnacle of a century of work on genes and genetics. It seemed as if the secrets of life were at our fingertips. The genetic blueprint of mankind... Nothing else, merely the whole human genetic code is a set of instructions to make a human being. Human genome is like a Bible where everything was written down. The hope and the expectation was that once we had that book in front of us, and all the letters we could just read down the pages, and we would understand how the body was put together. It would offer a complete understanding of human biology at a molecular level. The hope was that once the code was written down, scientists could find the genetic cause and cure for every disease. New Words & Phrases: pediatrician : A pediatrician is a doctor who specializes in treating sick children. AM(=paediatrician) 小儿科医师 chromosome : A chromosome is a part of a cell in an animal or plant. It contains genes which determine what characteristics the animal or plant will have. 【生】染色体 floppy : Something that is floppy is loose rather than stiff, and tends to hang downwards. 松软的;懒散的;下垂的 bizarre : Something that is bizarre is very odd and strange. 奇异的;异乎寻常的 genetic blueprint : A genetic blueprint is a pattern which is contained within all living cells. This pattern decides how the organism develops and what it looks like. eg. The offspring contain a mixture of the genetic blueprint of each parent... |
原文地址:http://www.tingroom.com/lesson/zrbaike/2007/498112.html |