[0:01.064]UNIT 2 第二單元
[0:02.741]DNA
[0:05.221]Lesson 11: 第11課:
[0:06.710]Cloning People? 克隆人?
[0:09.887]What if scientists could make clones of human beings? 如果科學(xué)家能夠克隆人類(lèi)會(huì)怎么樣?
[0:14.388]Each clone would have the same DNA. 每一個(gè)克隆人都有著同樣的DNA。
[0:17.860]But would they be exactly the same as the original human? 但是他們會(huì)和原來(lái)的人一模一樣嗎?
[0:21.818]Or would they be different? 或者他們是不同的?
[0:24.948]Good question! 好問(wèn)題!
[0:26.578]In some ways, 從某些方面來(lái)說(shuō),
[0:27.913]clones would be exactly the same. 克隆人會(huì)是一模一樣的。
[0:30.637]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(fā)。
[0:35.905]But each clone would be a different person. 但是,每一個(gè)克隆人都是不一樣的。
[0:38.716]Why? 為什么?
[0:39.827]Because we are more than our DNA. 因?yàn)槲覀儾恢故蹹NA的影響。
[0:42.484]Many things change us: 很多事情可以改變我們:
[0:44.351]the places we live, the food we eat and the people we know. 我們居住的環(huán)境,我們吃的食物和我們認(rèn)識(shí)的人。
[0:49.642]Did you know? 你知道嗎?
[0:51.391]· We can only make clones from living DNA. · 我們只能用活的DNA來(lái)進(jìn)行克隆。
[0:54.903]After a person or animal has died, 一個(gè)人或者動(dòng)物死后,
[0:58.001]we cannot clone them. 我們就無(wú)法克隆了。
[1:00.231]· There are two ways to clone people. · 克隆人類(lèi)有兩種方法。
[1:03.101]We can divide a growing egg in half. 我們可以把一個(gè)成長(zhǎng)中的胚胎分成兩部分。
[1:06.385]Then we would have two eggs with the same DNA. 然后我們就有了兩個(gè)有著一模一樣DNA的胚胎。
[1:10.460]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(gè)成年人,用跟克隆多利一樣的方法,就是那只克隆羊。
[1:19.036]Would cloning humans be a good or bad thing? 克隆人類(lèi)是好事,還是壞事?
[1:23.076]· Why would you clone someone? · 為什么要克隆人類(lèi)呢?
[1:25.119]Some people worry about the answer to that question. 有些人擔(dān)心那個(gè)問(wèn)題的答案。
[1:28.533]· Other people think human cloning is okay. · 有些人覺(jué)得克隆人類(lèi)是可以的。
[1:31.883]It may let scientists find new ways to help sick people. 它可以幫助科學(xué)家找出幫助病人的新方法。
[1:36.674]I think it would be fun to have a twin, 我覺(jué)得有一個(gè)雙胞胎很有意思,
[1:39.188]but I don't think I would want to be cloned! 但是我不想被克隆!
[1:42.990]Changing DNA 改變DNA
[1:45.692]Can they do that? 他們能這樣做嗎?
[1:47.813]Have you ever seen a pig with a dog's body? 你有沒(méi)有見(jiàn)過(guò)一頭長(zhǎng)著狗的身體的豬?
[1:50.735]Of course not! 當(dāng)然沒(méi)有!
[1:52.259]Pigs and dogs can't have babies. 豬和狗不能生孩子。
[1:54.835]They can't combine their DNA. 它們不能合成它們的DNA。
[1:57.600]But now, scientists can. 但是現(xiàn)在,科學(xué)家可以。
[2:00.318]Scientists can take DNA from one kind of animal 科學(xué)家們能夠從一種動(dòng)物中提取DNA,
[2:03.947]and put it into another kind of animal. 并把它放進(jìn)另一種動(dòng)物體內(nèi)。
[2:07.011]They can design new plants by combining the DNA of other plants. 他們可以通過(guò)合成DNA來(lái)研究出新的植物。
[2:12.132]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(dòng)物的DNA進(jìn)行合成。
[2:17.505]What kind of DNA are they wearing? 他們有著什么樣的DNA?
[2:20.961]Did you know that scientists have changed the DNA of some cotton plants? 你知道科學(xué)家們改變了某種棉花的DNA嗎?
[2:25.753]Many clothes are made of cotton. 許多衣服都是用棉花做的。
[2:28.266]Why did scientists change the DNA of cotton plants? 為什么科學(xué)家要改變棉花的DNA呢?
[2:31.786]Because insects damage many cotton plants. 因?yàn)橛行├ハx(chóng)毀壞了棉花。
[2:34.912]By changing the DNA, scientists made stronger cotton plants. 通過(guò)改變DNA,科學(xué)家創(chuàng)造了更健壯的棉花。
[2:40.866]What else have scientists designed by changing DNA? 科學(xué)家通過(guò)改變DNA還研究出了什么?
[2:45.626]· A new kind of corn. · 一種新型玉米。
[2:47.653]Ordinary corn has a problem: insects like to eat it! 一般的玉米有一個(gè)問(wèn)題:遭蟲(chóng)咬!
[2:52.350]But they don't like to eat the new corn. 但它們不喜歡吃新型的玉米。
[2:55.508]· A new kind of rice. · 一種新型水稻。
[2:57.519]Ordinary rice doesn't have Vitamin A. 一般的水稻沒(méi)有維他命A。
[3:00.771]The new rice does, and it's better for you. 新的水稻有,這對(duì)你有好處。
[3:04.368]· Cows that make more milk. · 奶牛產(chǎn)更多的牛奶。
[3:07.573]What's next? 接著是什么?
[3:09.930]Some scientists are worried. 科學(xué)家很擔(dān)心。
[3:12.318]They say we need to know more about DNA before we start changing it. 他們說(shuō)我們必須在改變它之前,知道更多關(guān)于DNA的東西。
[3:17.554]We can make plants that are bad for insects. 我們可以造出對(duì)昆蟲(chóng)不利的植物。
[3:20.617]But what if the plants are bad for humans, too? 但是如果這些植物對(duì)人類(lèi)也有害呢?
[3:23.728]Humans are us! 人類(lèi)就是我們!
[3:25.283]People! 人類(lèi)!
[3:26.597]LET'S DO IT! 做一做
[3:28.157]A debate is an argument between two groups. 辯論是兩個(gè)組之間的爭(zhēng)辯。
[3:33.036]One group argues for an idea; 一組為一個(gè)觀點(diǎn)爭(zhēng)辯;
[3:36.070]the other argues against it. 另一組反對(duì)那個(gè)觀點(diǎn)。
[3:39.077]Plan a debate about this topic: 準(zhǔn)備一個(gè)關(guān)于這個(gè)話題的辯論:
[3:42.283]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(gè)好主意嗎?
[3:48.506]Some people say doing this makes our food better. 一些人說(shuō)這樣做會(huì)使我們的食物更好.
[3:52.771]Others think it is too dangerous. 其他人認(rèn)為這太危險(xiǎn)了。
[3:55.962]Search the Internet for information to help your argument! 從網(wǎng)上查找資料幫助你辯論。
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