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  3. How can one person enjoy good health, while another person looks old before her time? Humans have been asking this question for

How can one person enjoy good health, while another person looks old before her time? Humans have been asking this question for

admin2023-01-31  5
问题     How can one person enjoy good health, while another person looks old before her time? Humans have been asking this question for thousands of years, and recently, it’s becoming clearer and clearer to scientists that the differences between people’s rates of aging lie in the complex interactions among genes, social relationships, environments and lifestyles. Even though you were born with a particular set of genes, the way you live can influence how they express themselves. Some lifestyle factors may even turn genes on or shut them off.
    Deep within the genetic heart of all our cells are telomeres, or repeating segments of noncoding DNA that live at the ends of the chromosomes (染色体). They form caps at the ends of the chromosomes and keep the genetic material together. Shortening with each cell division, they help determine how fast a cell ages. When they become too short, the cell stops dividing altogether. This isn’t the only reason a cell can age—there are other stresses on cells we don’t yet understand very well—but short telomeres are one of the major reasons human cells grow old. We’ve devoted most of our careers to studying telomeres, and one extraordinary discovery from our labs is that telomeres can actually lengthen.
    Scientists have learned that several thought patterns appear to be unhealthy for telomeres, and one of them is cynical hostility. Cynical hostility is defined by high anger and frequent thoughts that other people cannot be trusted. Someone with hostility doesn’t just think, "I hate to stand in long lines"; they think, "Others deliberately sped up and beat me to my rightful position in the line!"—and then get violently agitated. People who score high on measures of cynical hostility tend to get more heart disease, metabolic disease and often die at younger ages. They also have shorter telomeres. In a study of British civil servants, men who scored high on measures of cynical hostility had shorter telomeres than men whose hostility scores were low. The most hostile men were 30％ more likely to have short telomeres.
    What this means: aging is a dynamic process that could possibly be accelerated or slowed—and, in some aspects, even reversed. To an extent, it has surprised us and the rest of the scientific community that telomeres do not simply carry out the commands issued by your genetic code. Your telomeres are listening to you. The foods you eat, your response to challenges, the amount of exercise you get, and many other factors appear to influence your telomeres and can prevent premature aging at the cellular level. One of the keys to enjoying good health is simply doing your part to foster healthy cell renewal.
What have scientists come to know better today?
选项 A、Why people age at different rates.
B、How genes influence the aging process.
C、How various genes express themselves in aging.
D、Why people have long been concerned about aging.
答案A
解析 根据题干中的scientists和know better today定位到第1段第2句。题目询问当今科学家对什么有了更深入的了解。第1段第2句中的clearer and clearer to scientists对应题干中的scientists come to know better。该句提到，最近，科学家越来越清楚地认识到人们衰老速度的差异(the differences between people’s rates of aging)受到一系列因素相互作用的影响。由此可见，当今科学家对造成人们衰老速度差异的原因有了更深入的了解。A项“为什么人们衰老的速度不同”符合题意。第1段第2句提到人们衰老速度的差异在于基因、社会关系、环境和生活方式之间复杂的相互作用，这句话没有特别说明基因对衰老过程的影响，故排除B项。第1段第3句提到生活方式会影响基因的表达，并没有说具体如何表达，故排除C项“不同基因在衰老过程中如何表现”。D项“为什么人们一直关注衰老”不是当今科学家研究的方向。
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