In pairs, look at these pictures and

discuss which ones are natural clones

and which ones are man-made. Think

about how they differ.

Dolly the sheep

It’s the most famous sheep in the world. Do you know how Dolly is different from other sheep?

She was cloned while the others were born naturally. It is the copy of another sheep.

What can you see

in the picture?

I can see a strawberry plant producing

runners in a natural form of cloning.

Who cut the stem

off the plant?

A gardener. And the gardener is going

to put it into a pot to produce another

plant. He is actually making a copy of

the plant.

What do you know about twins?

There are twins of the same sex and those of different sexes. The twins here are identical in sex and appearance and are good examples of natural clones. They carry the same genetic information. The fertilized egg has split into two while inside the mother, and so produced two identical human babies.

Are the following clones the same?

If not, what is the difference?

NO. The first two are man-made clones,

the rest two are natural clones.

Pre-reading

Questions about cloning:

1. What is a clone?

A clone is an animal or plant

produced naturally or artificially

from the cells of another animal or

plant and is exactly the same as it.

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?1) Medical cloning can help cure serio

us illnesses that ruin one’s quality o

f life (such as Parkinson’s disease

帕金森症 or Alzheimer’s disease

老年痴呆症 ).

2) It can help infertile people have ba

bies.

4. What problems may arise when

humans are cloned?

1) People may want to clone themselves

so they can live forever.

2) People may want to clone dead

children.

3) People may want to clone their

favorite pets.

ComprehendingComprehending

I. Find the main idea of each paragraph.

Cloning is a way of making an exact copy of another animal and plant.Cloning has two major uses.The birth and death of Dolly.The effect of Dolly.It is forbidden to clone human beings.

Para 1.

Para 2. Para 3. Para 4. Para 5.

1). The main idea of the text is____ A. animal cloning is very valuable and can

benefit the world. B. animal cloning could be misused by bad

people so it must be forbidden C. animal cloning is well developed because

Dolly the sheep was born.

D. animal cloning raised arguments and scientists are not sure about its future.

III. Choose the best answer.

细枝末节

2. ________ is used in the procedure

for cloning Dolly the sheep.

A. The nucleus of Sheep A

B. The somatic cell of Sheep A

C. The nucleus of Sheep B

D. The embryo of Sheep C

3). The cloning of Dolly the sheep succeeded because____. A. its easier to clone a sheep than other animals B. the scientists were determined and worked hard with patience

C. the scientists were rewarded and got lots of money

D. many other attempts to clone mammals failed

4). The lamb is the clone of the cell from

sheep because_____.

A. it provides the egg cell

B. it gives birth to the

lamb C. it

provides the nucleus

D. it is a female sheep

5). Dolly the sheepA. looked exactly like the sheep that provid

es the eggB. was the exact copy of the sheep that prov

ides the nucleusC. looked like the sheep that gave birth to itD. had the characteristics of all three sheep

6). It can be inferred from the passage that

a cloned animal.

A.usually lives as long as the original one

B. usually lives longer than the original one

C. usually dies earlier than the original one

D. is usually as healthy as the original one

7). Which of the following is wrong?A. Cloned people would live forever.B. Cloned people may be killed at will for

medical aid.C. A woman would have difficulty recognizing her real husband.D. Men will die out because a woman can give birth to a baby without a husband.

8). The sheep that donated the somatic

cell most probably lived ____ years.

A. 3 B. 6 C. 12 D.

13

推理判断

9). Which of the follow is NOT a problem or danger of cloning mentioned in the text?

A. Evil leaders may want to clone themselves.

B. Animal clones may develop the illness of older animals and may die younger than the donor animals.

C. There are moral objections to cloning human beings.

D. Too much cloning may lead to the destruction of the balance of nature.

10). Which of the following is not an advantage of cloning?

A. Cloning can be used for medical purposes.B. Large quantities of food can be produced by cloning.C. Famous persons who have passed away can be cloned.D. Cloning can help keep animals from becoming extinct.

11). In the second paragraph, the w

ord “straightforward” means _

___.

A. uncomplicated B. honest

C. frank D. difficult

12). From the last paragraph we can infer that ____.

A. cloning will come to an end because of the objections

B. cloned human beings will be produced in the near future

C. many countries will use cloning in a wise way

D. all the research into human beings will be forbidden

C

Do you know about: the procedure works of a

sheep?

克隆羊诞生图示

“ 多利”的诞生标志着克隆研究取得新的进展和重大突破 , 而且这个结果证明 : 动物体中执行特殊功能 , 具有特定形态的所谓高度分化的细胞与受精卵一样具有发育成完整个体的潜在能力。也就是说 , 动物细胞与植物细胞一样 , 也具有全能性。

“ 多利”的诞生有什么重大的意义和影响？

What do you think of human cloning?

What’s your opinion of cloned food?

Have you ever wished you could have a clone of yourself to do homework while you had a rest or went out with your friends?

1. 克隆技术现在还不成熟 , 克隆人可能有很多先天性生理缺陷。

2. 克隆人的身份难以认定 , 他们与被克隆者之间的关系无法纳入现有的伦理体系。

反对克隆人

3. 克隆技术有可能被滥用 , 成为恐怖分子的工具。

4. 从生物多样性上来说 , 大量基因结构完全相同的克隆人 , 可能诱发新型疾病的广泛传播 , 对人类的生存不利。

1. “ 不让我们克隆人 , 就是不让我们修正我们的错误 , 人类 历史难道能够这样构造吗？”—《纽约时报书评》

2. “ 当然应该‘克隆’人 , 如果谁第一个掌握了这个技术 ,

他就是我真正的、也是唯一的竞争对手。”—比尔 · 盖茨

支持克隆人

3. “ 克隆人绝对是科学上了不起的进步 ,

克隆技术必将创造 21 世纪的辉煌。” —麻省理工学院生命工程教授约翰 ·

布洛克4. “ 人体商业化是人类经济活动中无与

伦比的成就 , 毫无疑问 , 克隆技术的出现将为世人创造一个最为广泛和深远的市场。” —英国《经济学家》杂志。