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 on and bad 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 reduced), while 160 were up regulated (their power was increased). Those affected included body-clock genes which are linked to diabetes. One of the most downgraded genes is that which has a role in controlling insulin and is linked to diabetes and insomnia. 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.
What kind of relation is directly discussed in the passage?（ ）
主旨题。阅读第一段、最后一段和每段第一句话，不难看出本文主要讲的是睡眠时间与人体内基因的关系。第二段中的 “a direct link between hours spent sleeping and genes” 更是直接地进行了表述。故选 A 。
What can we learn about Professor Derk-Jan Dijk's experiment?（ ）
推断题。定位于第三段和第四段。根据第三段的第一句话“Can sleep affect how a gene reads instructions?”可知Derk-Jan Dijk教授的实验是为了发现睡眠对人体基因变化的影响．而不是基因影响睡眠，故A项不正确。根据第三段的最后一句话“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．”可知，他并没有将志愿者进行分组，而是要求他们第一周每晚睡七个半到八个小时，第二周将睡眠时间调整为六个半到七个小时，故C项不正确。再结合第四段的前两句话，他将志愿者这两周的血液样本进行比对，观察基因运作情况的不同．实验结果令人大吃一惊。由此可推断出，这个实验进行了两周多才得出结论，故B项正确，D项不正确，采集血液样品是为了比较在不同睡眠时长下所用到的基因的不同，而不是多少基因被改变。
Which of the following may be concluded from the passage?（ ）
推断题。根据第五段内容可知，睡眠时间不足可能引起人体基因的变化，而这些基因变化可以导致人体某些病症的产生，如糖尿病、失眠症、心脏病等，故C项正确。文章第二段的第一句话中虽然提到了“In the first half of 2013”和“at the University of Surrey”．但这里指的是英国萨里大学睡眠研究中心的一项发现，而不是指后来Derk-Jan Dijk教授所进行的实验，故A项不正确。文中提到了body-clock genes(控制生物钟的基因)与糖尿病有关，并没有提到它们和其他疾病的关系，故B项不正确。根据倒数第二段“So changing sleep by tiny amounts Can upgrade or downgrade genes that Can influence our health…”及最后一段“The important message is that getting close to eight hours of sleep a night can make a dramatic difference to our health…”可知D项不正确。故本题选C。
Which of the following can be inferred from the findings of the sleep research?（ ）
推断题。根据文章最后一段 “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 ． ” 可知， 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我们的基因， D 项是此段话的同义表达，故选 D 。 A 项属于原文的直接信息，不用推断。 B 项说法错误，改变越多，并不一定意味着结果越差，要看这种改变是导致基因活性降低还是上升。文章第五段中提到，在下调程度最高的基因中，有一种负责控制胰岛素合成的基因与糖尿病和失眠密切相关，而上调程度最高的基因则与心脏病有关联，可见基因下调和上调均可能对健康有害，故 C 项说法错误。