高中英语选修8unit2 warming-up,pre-reading and reading

Warming upIn pairs, look at these pictures anddiscuss which ones are natural clones

and which ones are man-made.Explain how they differ.

A strawberry plant

The new plants that grow from the runners are exact copies of the original plant.

一株草莓依靠它沿地“爬走”的匍匐 茎,一年内就能长出数百株草莓苗

Growing new plants

Twins

They are born naturally and identical in sex and appearance.

Dolly是世界上第一例用体细胞─ 乳腺上皮细胞,通

过细胞核移植技术,在复杂的人工

操作下,得到的一只小绵羊 。

what is the difference among them ?

Natural clone

Man-made clone

Natural clone is one that occurs from the “parent ” in a natural form of cloning without human help.

Man-made clone is one that produced through human intervention(介入) .

Pre-readingIn pairs discuss what youunderstand about cloning. Then list

the questions you want to findout .Share your lists with one

another.

Questions about cloning

1. What is a clone?

富贵竹插枝即活

仙人掌每块落地就生根

克隆的荧光小猪(左)和正常小猪(右)

Questions about cloning1. What is a clone?A clone is group of cells or organisms that are genetically identical and have been produced asexually(无性生

殖 /繁殖)from the same original cell.They include natural and man-made

clones.

克隆,是Clone的译音,意为生物体 通过细胞进行的无性繁殖形成的基 因型完全相同的后代个体组成的种 群,简称为"无性繁殖"。 "克隆"一 词于1903年被引入园艺学,以后逐 渐应用于植物学、动物学和医学等 方面。

2. How is a clone 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 and is fully explained in the first reading.

3. What benefits can humans gain from cloning?