Every newborn baby is dealt a genetic hand of cards which helps to determin

游客2023-11-18  20

问题      Every newborn baby is dealt a genetic hand of cards which helps to determine how long he or she will be allowed to play the game of life. There are good cards, which predispose those who have them to a long and healthy existence, and there are bad cards, which predispose people to high blood pressure, say, or heart disease. Occasionally, cards are dealt out that doom their holders to an early death. In the past, people never knew exactly which cards — in other words, which genes — they had been dealt. They could guess at the future only by looking at the kind of health problems experienced by their parents or grandparents.
     Genetic testing, which makes it possible to probe for dangerous genes, has changed all this. But, until recently, if you tested positive for a bad gene, you were not obliged to reveal this to anyone else except in a few extreme circumstances. This month, however, Britain became the first country in the world to allow life insurers to ask for test results.
     So far, approval has been given only for a test for a fatal brain disorder known as Huntington’s disease. But ten other tests (for seven diseases) are already in use and are awaiting similar approval.
     The independent body that gives approval, the Department of Health’s Genetics and Insurance Committee does not have to decide whether the use of genetic information in insurance is ethical. It must judge only whether the tests are believable to insurers. In the case of Huntington’s disease the answer is clear-cut. People unlucky enough to have this gene will die early, and cost life insurers dearly.
    This is only the start.  Clear-cut genetic answers, where a gene is simply and directly related to a person’s risk of death, are uncommon.  More usually, a group of genes is associated with the risk of developing a common disease, dependent on the presence of other genetic or environmental factors. But, as tests improve, it will become possible to predict whether or not a particular individual is at risk. In the next few years researchers will discover more and more about the functions of individual genes and what health risks or benefits — are associated with them. [br] What is the author’s purpose of writing the passage?

选项 A、To show the way genetic testing works.
B、To indicate the relation between genes and Huntington’s disease.
C、To reveal the influence of environmental factors on genes.
D、To introduce genetic testing and its functions.

答案 D

解析 主旨题。根据文章所阐述的内容,文章主要介绍了基因测试及其作用,因而正确答案是 D  A  “表明基因测试是如何进行的”只是文章内容的一个方面;B  “显示基因和亨廷顿疾病之间的关系”,这只是在第三段提到,不是主要内容;C  “揭示环境因素对基因的影响”,这部分的内容只是在最后一段提到,也不是主要内容。
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