下载此文档
搜索文档
阅读：
文档下载
【#第一文档网# 导语】以下是®第一文档网的小编为您整理的《选修八Unit_2 Cloning原文翻译》，欢迎阅读！
Uint2 Cloning
Cloning has always been with us and is here to stay. It is a way of making an exact copy of another animal or plant. It happens in plants when gardeners take cuttings from growing plants to make new ones. It also happens in animals when twins identical in sex and appearance are produced from the same original egg. The fact is that these are both examples of natural clones.
Cloning has two major uses. Firstly, gardeners use it all the time to produce commercial quantities of plants. Secondly, it is valuable for research on new plant species and for medical research on animals. Cloning plants is straightforward while cloning animals is very complicated. It is a difficult task to undertake. Many attempts to clone mammals failed. But at last the determination and patience of the scientists paid off in 1996 with a breakthrough - the cloning of Dolly the sheep. The procedure works like this:
On the one hand, the whole scientific world followed the progress of the first successful clone, Dolly the sheep. The fact that she seemed to develop normally was very encouraging. Then came the disturbing news that Dolly had become seriously ill. Cloning scientists were cast down to find that Dolly's illnesses were more appropriate to a much older animal. Altogether Dolly lived six and a half years, half the length of the life of the original sheep. Sadly the same arbitrary fate affected other species, such as cloned mice. The questions that concerned all scientists were: "Would this be a major difficulty for all cloned animals? Would it happen forever? Could it be solved if corrections were made in their research procedure?"
On the other hand, Dolly's appearance raised a storm of objections and had a great impact on the media and public imagination. It became controversial. It suddenly opened everybody's eyes to the possibility of using cloning to cure serious illnesses and even to produce human beings.
Although at present human egg cells and embryos needed for cloning research are difficult to obtain, newspapers wrote of evil leaders hoping to clone themselves to attain their ambitions. Religious leaders also raised moral questions. Governments became nervous and more conservative. Some began to reform their legal systems and forbade research into human cloning, but other countries like China and the UK, continued to accumulate evidence of the abundant medical aid that cloning could provide. However, scientists still wonder whether cloning will help or harm us and where it is leading us.
Unit 2 克隆：他将把我们引向何方？
克隆一直与我们同在，而如今它还要坚持下去。这是一种用来生产与原型完全相同的动植物的方法。当园艺师从生长的植物上剪下枝条来培植新植物时，就会产生这种现象。这种现象也发生在动物身上，从同一个原生卵子产生性别和相貌相同的双胞胎也是克隆。实际上，这
2022-04-25
