英语听力精选进阶版 6427

What's wrong with having three parents? I'm happy with two but maybe it would have been a case of the more the merrier.

The role of parents is not only to give us love and guidance, but also to pass on genetic¹ code.

A few particular healthy genes² would be the contribution of the third parent, according to a British government decision to support a ground-breaking technique for preventing genetic disease.

It has to do with the mitochondria, the energy factory we have in our cells. They contain just 37 genes and sit outside the nucleus³ which has more than 20,000 genes. Diseases caused by faulty mitochondria are serious and are passed down the maternal⁴ line in the egg, so the technique being pioneered by Newcastle University involves using healthy donor⁵ eggs.

After fertilisation, the genes of the father and the mother would be transferred from the embryo⁶ to the healthy donor egg, which has had the genetic material from its nucleus removed but still has good mitochondria.

To explain the technique, scientists in Newcastle compared it to changing the battery of a laptop computer. Like in the hard-drive, nothing changes in the DNA⁷ of the two parents because they are in the nucleus.

The government will prepare regulations later this year and the technique could be available within two years. Faulty mitochondria affect one in every 6,500 babies and it can cause lack of energy and result in muscle weakness, blindness and heart failure.

Some people are opposed to this because they consider it unethical and say it could set the UK on a slippery slope. The nightmare of creating a Frankenstein's monster is always in our mind. They also say that couples with the problem could adopt a child instead.

But the same was said when the world's first test tube baby, Louise Brown, was born in Britain in 1978. And the only Frankenstein we see is in the movies.

The fact is that families are changing all the time. Who knows what the typical family will be like in 50 years' time...

Quiz 测验

1. What's the purpose of the new technique?

It was developed to prevent genetic diseases caused by faulty mitochondria.

2. What did scientists in Newcastle compare it to?

To changing the battery of a laptop computer.

3. How can faulty mitochondria affect a person?

It can lead to muscle weakness, blindness and heart failure.

4. Was Louise Brown born with three genetic parents?

No. She was born in 1978 and the three-parent technique is being developed now.

5. Name four elements of a cell mentioned in the article.

Genes, nucleus, mitochondria, DNA.

Glossary 词汇表

the more the merrier 越多越好

the genetic code 遗传密码

a gene 基因

ground-breaking 突破性的，具有开创性的

genetic 遗传的

mitochondria (plural) 线粒体（复数）

a cell 细胞

the nucleus (of a cell) 细胞核

maternal line 母系

to pioneer 开创，倡导

a donor egg 捐赠的卵子

fertilisation 受精

an embryo 胚胎

the hard-drive 硬盘

DNA 脱氧核糖核酸

the regulations 规章制度，条例

muscle weakness 肌无力

unethical 不合乎道德准则的

a slippery slope 滑坡，难以阻止、控制的困境

to adopt (a child) 领养（一个孩子）

a test tube baby 试管婴儿

1 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

2 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

3 nucleus   

n.核，核心，原子核

参考例句：

• These young people formed the nucleus of the club.这些年轻人成了俱乐部的核心。
• These councils would form the nucleus of a future regime.这些委员会将成为一个未来政权的核心。

4 maternal   

adj.母亲的，母亲般的，母系的，母方的

参考例句：

• He is my maternal uncle.他是我舅舅。
• The sight of the hopeless little boy aroused her maternal instincts.那个绝望的小男孩的模样唤起了她的母性。

5 donor   

n.捐献者；赠送人；(组织、器官等的)供体

参考例句：

• In these cases,the recipient usually takes care of the donor afterwards.在这类情况下，接受捐献者以后通常会照顾捐赠者。
• The Doctor transplanted the donor's heart to Mike's chest cavity.医生将捐赠者的心脏移植进麦克的胸腔。

6 embryo   

n.胚胎，萌芽的事物

参考例句：

• They are engaging in an embryo research.他们正在进行一项胚胎研究。
• The project was barely in embryo.该计划只是个雏形。

7 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。