Question

    A genetic variant(基因变体) that allows people to feel fully rested with fewer than six hours sleep a night has been found. It is the second such finding in recent months.

Ying-Hui Fu at the University of California, San Francisco, and her colleagues have been seeking out genetic variants responsible for short sleep and genetically engineering these variants into mice to confirm their effect. In August. the team found a variant in a gene called ADRB1, which allows 12 members of a family to sleep 4.5 hours per night without feeling tired.

Now the team has found a variant in a gene called NPSR1 in another family, in which one sleeps averaged 5.5 hours a night and the other just 4.3 hours, feeling fully rested. Another variant in NPSR1 has previously been linked to people requiring 20 minutes less sleep than average, based on studies of tens of thousands of people.

Generally, long-term lack of sleep can contribute to many disorders, including obesity, heart disease, high blood pressure and depression. As far as Fu’s team has been able to tell, however, people who sleep less with one of these gene variants are healthy and don’t appear to suffer any ill effects. However, to be absolutely sure would require long-term studies involving large numbers of people, which is not feasible(可行的).

It might be possible to develop drugs that mimic the effects of these variants. However, as NPSR1 is also involved in processes such as stress, anxiety and fear, there is a risk of serious side effects.

1.What did Fu’s team do to confirm the variants effect?

A.Observed blood pressure change.

B.Tested genetic variants on mice.

C.Sorted the effects of different genes.

D.Studied those sleeping less than average.

2.What can we learn about Fu’s team?

A.They are researching variants controlling sleep.

B.They study NPRS1 in a family of 12 members.

C.They have developed drugs to test normal people.

D.They will discover more variants in a week.

3.What does the word “mimic”in the last paragraph mean?

A.Reproduce. B.Compare. C.Avoid. D.Reduce.

4.Where does the text probably come from?

A.A news report. B.A health magazine.

C.A research paper. D.A biology textbook.

Answer

1.B

2.A

3.A

4.B

【解析】

这是一篇说明文。文章介绍了一项新发现。是一种基因变体，它能让晚上睡眠少于6个小时的人感觉休息的很好。带有这种基因变体的人，睡眠偏少但依然健康，而且没有显现出生病的征兆。因此可以仿造这种基因变体制造药物，但不排除有副作用。

1.细节理解题。由第二段genetically engineering these variants into mice to confirm their effect.可知在基因技术上，这些变体被用在老鼠身上，来确认其效果。所以傅的团队团队为了确认变体的效果，在老鼠身上用变体做试验。故选B。

2.推理判断题。由倒数第二段Ying-Hui Fu at the University of California, San Francisco, and her colleagues have been seeking out genetic variants responsible for short sleep and genetically engineering these variants into mice to confirm their effect.可知傅颖惠和她的同事一直在寻找导致睡眠不足的基因变异，也在老鼠上做试验来确认效果。所以傅的团队在研究控制睡眠的变体。故选A。

3.词义猜测题。前文说到带有这种基因变体的人，睡眠偏少但依然健康，而且没有显现出生病的征兆。因此也许可以制造药物，使药物与变体有一样的效果。即：药物再现变体的作用。reproduce意为再现、复制。故选A。

4.推理判断题。文章中傅的团队在研究控制睡眠的变体。由倒数第二段people who sleep less with one of these gene variants are healthy and don’t appear to suffer any ill effects.可知有这些变体且睡眠少的人健康且，但没有健康问题。所以研究与健康有关，可能来自健康杂志。故选B。