Question

I’ve often wondered how exactly sleep, or lack of it, can have such an awful effect on our bodies and, guess what, how much we sleep switches good genes(基因) on and had genes off.

In the first half of 2013, the Sleep Research Centre at the University of Surrey found a direct link between hours spent sleeping and genes. Every cell in our bodies carries genetic instructions in our DNA that act as a kind of operating handbook. However, each cell only “reads” the part of this handbook it needs at any given moment.

Can sleep affect how a gene reads instructions? It’s a question asked by Professor Derk-Jan Dijk at the University of Surrey. He set up an experiment and asked his volunteers to spend a week sleeping around seven and a half hours to eight hours a night and the next sleeping six and a half to seven hours.

Blood samples were taken each week to compare which genes in blood cells were being used during the long and short nights. The results were rather surprising. Several hundred genes changed in the amount they were being used, including some that are linked to heart disease, cancer, and Type 2 diabetes. Genes to do with cell repair and replacement were used much less.

Sleep restriction(six and a half to seven hours a night) changed 380 genes. Of these, 220 genes were down regulated (their power was increased). Those affected included body-clock genes which are linked to diabetes(糖尿病). One of the most downgraded genes is that which has a role in controlling insulin(胰岛素) and is linked to diabetes and insomnia(失眠). The most upgraded gene is linked to heart disease.

So changing sleep by tiny amounts can upgrade or downgrade genes that can influence our health and the diseases we suffer from when we sleep too little.

The important message is that getting close to eight hours of sleep a night can make a dramatic difference to our health in just a few days through the way it looks after our genes.

1.What kind of relation is directly discussed in the passage?

A. Sleeping hours and changes of genes.

B. Sleeping hours and diseases.

C. Changes of genes and diseases.

D. Genes and health.

2.What can we learn about Professor Derk-Jan Kijk’s experiment?

A. The experiment was carried out to find the answer to how genes affect sleep.

B. The experiment took a period of more than two weeks to reach a conclusion.

C. His volunteers were divided into two groups with two different sleeping patterns.

D. Blood samples of the volunteers were checked afterwards to decide how many genes changed in sleeping.

3.Which of the following may be concluded from the passage?

A. The experiment was performed at the University of Surrey in early 2013.

B. Body-clock genes are associated with heart disease, cancer and Type 2 diabetes.

C. Sleep restrictions may contribute to disease like diabetes, insomnia, and heart disease.

D. 7.5－8 hours’ sleep pattern makes little difference compared with 6.5－7 hours’ sleep pattern.

4.Which of the following can be inferred from the findings of the sleep research?

A. When there is a sleep restriction, genes to do with cell repair and replacement function less.

B. In a sleep, several hundred genes change in the amount. The more changes, the worse results.

C. When genes are up regulated, they do good to health; when genes are down regulated , they do harm to health.

D. Eight hours of sleep a day can be beneficial to our health in that it looks after our genes.

Answer

1.A

2.C

3.C

4.D

【解析】

试题分析：本文介绍了睡眠时间对身体健康的影响。

1.A 细节理解题。根据文章第一段中how much we sleep switches good genes(基因) on and had genes off.可知，文章是要讲述睡眠时间与人体内基因在睡眠状态下产生变化之间的关系。故选A。

2. 细节理解题。根据第三、四段可知，实验主要目的是发现睡眠时间长短对人体基因变化的影响，而不是基因影响睡眠，故A不正确。实验是分两组进行，志愿者进行两种睡眠时间的测试，故选C。

3.C 细节理解题。根据倒数第二段的内容可知，睡眠时间不足可能引起人体基因的变化，而这些人体基因变化是导致人体某些病症的产生，如糖尿病，失眠症，心脏病的产生等，故选C。

4. 推理判断题。根据文章最后一段的描述，8个小时的睡眠模式对人体是非常有益的，因为这样的睡眠时间能很好地照料决定人体健康方面的基因，故选D。

考点：考查科普类阅读

【名师点睛】

科普类的阅读理解一般为介绍科学知识、社会知识的文章。阅读这类短文时，要以文章事实为中心进行思考。

答题技巧：

1. 加强整体意识，把握文章的主要内容。给重要的句子和关键词做上记号，特别是各段中心句，可以更快捷的答题。比如第28题：主旨大意题。本文是要讲述的是睡眠时间与人体内基因在睡眠状态下产生变化之间的关系。故选A。

2. 审清题干，弄清楚问题的要点，从文章对应处寻找答案。

要熟悉科普类文章的结构特点。科普类文章一般由标题(Head line)，导语(Introduction)，背景(Back ground)，主体(Main body)和结尾(End)五部分构成。

标题是文章中心思想高度而又精辟的概括，但根据历年的高考情况来看，这类阅读理解材料一般不给标题，而要同学们选择标题。

导语一般位于整篇文章的首段。背景交待一个事实的起因。

主体则对导语概括的事实进行详细叙述，这一部分命题往往最多，因此，阅读时，同学们要把这部分作为重点。比如第29题：细节理解题。根据第三、四段可知，实验主要目的是发现睡眠时间长短对人体基因变化的影响，而不是基因影响睡眠，故A不正确。实验是分两组进行，志愿者进行两种睡眠时间的测试，故选C。

结尾往往也是中心思想的概括，并与导语相呼应，命题者常在此要设计一道推理判断题。