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Book 8 unit 2
Warming up Two kinds of clones: Nat
ural clone is one that occurs
in a natural form of cloning without human help. Man-made clone is one that is produced through human
In pairs, look at these pictures and
discuss which ones are natural
clones and which ones are manmade. Explain how they differ.
A strawberry plant
The new plants that grow from the runners are exact copies of the original plant.
The plant produces its own runners. 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
A stem Take cuttings from growing plants to make new ones.
The gardener cuts the plant ,and then the cutting produces another new plant.
They are born naturally and identical in sex and appearance.
操作下,得到的一 只小绵羊 。
In 1996, a sheep called Dolly was born. It is the first mammal to be cloned. It is considered to be the greatest success in the development of cloning.
How does Dolly differ from other sheep? She was cloned while the others were born naturally.
Dolly was a cloned ______ sheep.
The following are some photos
about cloning. See how much you know about it.
2001 cloning cattle
2002 cloning cats
2002 cloning rabbits
2003 Cloning horse
克隆的荧光小猪(左)和正 2005 cloning dogs 常小猪(右)
In pairs discuss what you understand
about cloning. Then list the questions
you want to find out. Share your lists
with one another.
Questions about cloning
1. 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.
Clone, also called reproduce asexually (无性生殖 /繁殖), is the creation of cells or whole animals using DNA from a single “parent”, without using the normal reproductive (有性生殖) process. The clone has the exactly same DNA to the parent. It includes natural and man-made clone.
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。但克 隆与无性繁殖是不同的。无性繁殖是 指不经过雌雄两性生殖细胞的结合、 只由
一个生物体产生后代的生殖方式,常见 的有孢子生殖、出芽生殖和分裂生殖。 由植物的根、茎、叶等经过压条或嫁 接等方式产生新个体也叫无性繁殖。 绵羊、猴子和牛等动物没有人工操作 是不能进行无性繁殖的。科学家把人 工遗传操作动物繁殖的过程叫克隆,这 门生物技术叫克隆技术。
克隆的基本过程是先将含有遗传物质 的供体细胞的核移植到去除了细胞核的卵 细胞中,利用微电流刺激等使两者融合为一
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 serious illnesses that ruin one’s quality of 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 babies.
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.
Please read the passage quickly
and get the main idea, and then
finish the following exercises in
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.
2. The cloning of Dolly the sheep succeeded because____. B 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
3. What is people's fear about human cloning. Which of the following is wrong?
A. Cloned Hitlers would do harm to the world. 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.
4. The sheep that donated the somatic
cell most probably lived ____ years.
5. We can infer from the last three paragraphs that ___. A. The normal development of Dolly had no effect on the cloning of other species. B. Dolly’s serious disease and final death disturbed the whole world. C. There were arguments about animal cloning and concerns about the future of cloning. D. Dolly successfully cloned a new lamb with the help of cloning scientists.
Listen to the tape and find out the main idea of
The main idea of each paragraph.
1.Cloning is a way of making an exact copy of another animal and plant. ______________________________
two major 2.Cloning has ____________ uses. problems of Dolly. 3.The _________ effect 4. The ________ of Dolly.
5. People’sreaction to cloning.
The definition of cloning
What is cloning ?
Cloning is a way of making an exact copy of another animal and plant.
plants and It happens both in ______ animals They can be cloned in_______. themselves and _______. humans by ________
Natural clone Man-made clone
The major uses and procedures of cloning Firstly, …commercial… Secondly, …research… In this paragraph, the word “straightforward” means ____. A. uncomplicated B. honest C. frank D. difficult
Do you know about: the procedure works of a
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.
The problems of Dolly
normally At first, the fact that Dolly developed ______ encouraging in a natural way was __________. that Later, the news _____Dolly had become disturbing seriously ill was __________. Finally, the problem that occurred to the scientists was that a cloned animal lives shorter than _____________ the original one.
as long as / shorter than / longer than
The impact of Dolly
a storm of objections Its’ appearance raised and had a great impact on the media and public imagination.
The word “controversial” in Para 4 probably means :____________. A. complicated B. arguable C. important D. traditional
Para 5 People’s reaction to cloning True or false:
1 People feared that Cloned Hitlers would do harm to the world.
Many governments forbade research 2 All the research into human beings will be forbidden. into human beings.
3 Some countries will use cloning in a wise way.
The writer’s attitude towards cloning
A. Objective (be fair) B. Negative (be against it) C. Positive (be in favor of it)
the author does not state Because____________________________
any personal opinion about cloning. _____________________________________
Fill in the chart using the information from the text.
Problems or dangers Advantages of cloning of cloning Animals may_______ develop Medical cloning could produce ______ cures for illnesses of older _______ the _______ ___ serious degenerative(变 animals. 质的）________ illnesses in humans.
Animal clones may Cloning plants can ___ _______ die _______ younger than ______ produce plants of quality for the donor animals similar _______ ___ _____. sale ____ leader _____ may Cloning plants can be Evil useful want to clone _____ for research on themselves. ________________ new plant species .
There are _____ moral __________ objections to cloning human beings.
Cloning can help save endangered _________ animals . ___________
Find the main idea of each paragraph. Para 1. Cloning is a way of making an exact copy of another animal and plant. Para 2. Cloning has two major uses. Para 3. The problems of Dolly. Para 4. The effect of Dolly. Para 5. It is forbidden to clone human beings.
Fill in the chart about the advantages and disadvantages of cloning.
Cloning is beneficial to humans It can make more profits for gardeners and farmers We could use cloning to cure illness Cloning can help save endangered animals Cloning can provide a copy of a child for a couple whose child has died
Animals clones get ill and die young Against nature Animals clones may develop the illness of older animals Evil leaders may want to clone themselves People are afraid that scientists will create thousands of copies of the same person.
Practice activity: Debate Are you in favor of cloning or against cloning? State your point of view on it. For ＶＳ Against
They have the same face. People are no longer special to each other.
Advantages of cloning
? Cloning plants can be useful for research on new ____ plant _____ species _______.
? Cloning plants can produce large quantities ________ of
sale plants for ____.
? Cloning is valuable for ________ medical research on
? Medical cloning could produce _____for cures serious
illnesses in humans.
Problems of cloning
? Animal clones may develop the illnesses ______
of older animals ? Animal clones may die younger _______ than the original animals.
?Evil ___ _______may want to clone themselves. leaders ? There are_____ moral _________ objections to cloning human
We can conclude _______
A. Cloning is good for us. B. Cloning has two aspects. C. If cloning is used in a correct way it can bring many convenience to us. D. If cloning is used in an evil way it can cause much trouble.
We should use cloning in a wise way !
As a coin has two sides, everything has two aspects. On one hand, if cloning is used in a correct way it can bring many convenience to us. On the other hand, if cloning is used in
an evil way it can cause much trouble.
Therefore, we should use cloning in a
Finish Ex.1, 2, 3 on Page13.