UNIT 2 DNA
第二單元 DNA
Lesson 11: Cloning People?
第11課：克隆人？
What if scientists could make clones of human beings?
如果科學家能夠克隆人類會怎么樣？
Each clone would have the same DNA.
每一個克隆人都有著同樣的DNA。
But would they be exactly the same as the original human?
但是他們會和原來的人一模一樣嗎？
Or would they be different?
或者他們是不同的？
Good question!In some ways,
好問題！從某些方面來說，
clones would be exactly the same.
克隆人會是一模一樣的。
They would be the same height and they would have the same hair colour,for example.
例如，他們一樣高，有著同樣顏色的頭發。
But each clone would be a different person.
但是，每一個克隆人都是不一樣的。
Why?Because we are more than our DNA.
為什么？因為我們不止受DNA的影響。
Many things change us:
很多事情可以改變我們：
the places we live,the food we eat and the people we know.
我們居住的環境，我們吃的食物和我們認識的人。
Did you know?
你知道嗎？
We can only make clones from living DNA.
我們只能用活的DNA來進行克隆。
After a person or animal has died,
一個人或者動物死后，
we cannot clone them.
我們就無法克隆了。
There are two ways to clone people.
克隆人類有兩種方法。
We can divide a growing egg in half.
我們可以把一個成長中的胚胎分成兩部分。
Then we would have two eggs with the same DNA.
然后我們就有了兩個有著一模一樣DNA的胚胎。
Or we could clone an adult person,the same way scientists cloned Dolly,the sheep.
或者，我們可以克隆一個成年人，用跟克隆多利一樣的方法，就是那只克隆羊。
Would cloning humans be a good or bad thing?
克隆人類是好事，還是壞事？
Why would you clone someone?
為什么要克隆人類呢？
Some people worry about the answer to that question.
有些人擔心那個問題的答案。
Other people think human cloning is okay.
有些人覺得克隆人類是可以的。
It may let scientists find new ways to help sick people.
它可以幫助科學家找出幫助病人的新方法。
I think it would be fun to have a twin,
我覺得有一個雙胞胎很有意思，
but I don't think I would want to be cloned!
但是我不想被克隆！
Changing DNA ,Can they do that?
改變DNA,他們能這樣做嗎？
Have you ever seen a pig with a dog's body?
你有沒有見過一頭長著狗的身體的豬？
Of course not!
當然沒有！
Pigs and dogs can't have babies.
豬和狗不能生孩子。
They can't combine their DNA.
它們不能合成它們的DNA。
But now,scientists can.
但是現在，科學家可以。
Scientists can take DNA from one kind of animal
科學家們能夠從一種動物中提取DNA，
and put it into another kind of animal.
并把它放進另一種動物體內。
They can design new plants by combining the DNA of other plants.
他們可以通過合成DNA來研究出新的植物。
They can even combine the DNA of a plant and an animal.
他們甚至可以將一種植物和一種動物的DNA進行合成。
What kind of DNA are they wearing?
他們有著什么樣的DNA？
Did you know that scientists have changed the DNA of some cotton plants?
你知道科學家們改變了某種棉花的DNA嗎？
Many clothes are made of cotton.
許多衣服都是用棉花做的。
Why did scientists change the DNA of cotton plants?
為什么科學家要改變棉花的DNA呢？
Because insects damage many cotton plants.
因為有些昆蟲毀壞了棉花。
By changing the DNA,scientists made stronger cotton plants.
通過改變DNA，科學家創造了更健壯的棉花。
What else have scientists designed by changing DNA?
科學家通過改變DNA還研究出了什么？
A new kind of corn.
一種新型玉米。
Ordinary corn has a problem: insects like to eat it!
一般的玉米有一個問題：遭蟲咬！
But they don't like to eat the new corn.
但它們不喜歡吃新型的玉米。
A new kind of rice.
一種新型水稻。
Ordinary rice doesn't have Vitamin A.
一般的水稻沒有維他命A。
The new rice does,and it's better for you.
新的水稻有，這對你有好處。
Cows that make more milk.
奶牛產更多的牛奶。
What's next?Some scientists are worried.
接著是什么？科學家很擔心。
They say we need to know more about DNA before we start changing it.
他們說我們必須在改變它之前，知道更多關于DNA的東西。
We can make plants that are bad for insects.
我們可以造出對昆蟲不利的植物。
But what if the plants are bad for humans,too?
但是如果這些植物對人類也有害呢？
Humans are us!People!
人類就是我們！人類！
LET'S DO IT!
做一做
A debate is an argument between two groups.
辯論是兩個組之間的爭辯。
One group argues for an idea;
一組為一個觀點爭辯；
the other argues against it.
另一組反對那個觀點。
Plan a debate about this topic:
準備一個關于這個話題的辯論：
is it a good idea to change the DNA of the food we eat?
改變我們吃的食物的DNA是一個好主意嗎？
Some people say doing this makes our food better.
一些人說這樣做會使我們的食物更好.
Others think it is too dangerous.
其他人認為這太危險了。
Search the Internet for information to help your argument!
從網上查找資料幫助你辯論。