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  3. Gene therapy and gene-based drugs are two ways we could benefit from our growing mastery of genetic science. But there will be o

Gene therapy and gene-based drugs are two ways we could benefit from our growing mastery of genetic science. But there will be o

admin2009-05-21  160
问题     Gene therapy and gene-based drugs are two ways we could benefit from our growing mastery of genetic science. But there will be others as well. Here is one of the remarkable therapies on the cutting edge of genetic research that could make their way into mainstream medicine in the coming years.
    While it’s true that just about every cell in the body has the instructions to make a complete human, most of those instructions are inactivated, and with good reason: the last thing you want for your brain cells is to start churning out stomach acid or your nose to turn into a kidney. The only time cells truly have the potential to turn into any and all body parts is very early in a pregnancy, when so-called stem cells haven’t begun to specialize.
    Yet this untapped potential could be a terrific boon to medicine. Most diseases involve the death of healthy cells--brain cells in Alzheimer’s, cardiac cells in heart disease, pancreatic cells in diabetes, to name a few. If doctors could isolate stem cells, then direct their growth, they might be able to furnish patients with healthy replacement tissue.
    It was incredibly difficult, but last fall scientists at the University of Wisconsin managed to isolate stem cells and get them to grow into neural, gut, muscle and bone cells. The process still can’t be controlled, and may have unforeseen limitations. But if efforts to understand and master stem-cell development prove successful, doctors will have a therapeutic tool of incredible power.
    The same applies to cloning, which is really just the other side of the coin; true cloning, as first shown with the sheep Dolly two years ago, involves taking a developed cell and reactivating the genome within, resetting its developmental instructions to a pristine state. Once that happens, the rejuvenated cell can develop into a full-fledged animal, genetically identical to its parent.
    For agriculture, in which purely physical characteristics like milk production in a cow or low fat in a hog have real market value, biological carbon copies could become routine within a few years. This past year scientists have done for mice and cows what Ian Wilmot did for Dolly, and other creatures are bound to join the cloned menagerie in the coming year.
    Human cloning, on the other hand, may be technically feasible but legally and emotionally more difficult. Still, one day it will happen. The ability to reset body cells to a pristine, undeveloped state could give doctors exactly the same advantages they would get from stem cells: the potential to make healthy body tissues of all sorts, and thus to cure disease. That could prove to be a true "miracle cure."
选项 A、there will inevitably be human cloning in the coming year
B、the potential to make healthy body tissues is undoubtedly a boon to human beings
C、it is illegal to clone any kind of creatures in the world
D、it is legal to clone any kind of creatures in the world except human
答案B
解析 这是一道细节题。文章第三段指出：对于医学来说，这种未被利用的潜能也许是一种极大的恩赐：大多数疾病与健康细胞的死亡有关，如果医生能够分离出主干细胞，然后令这些细胞发育，那么他们就可以为病人提供健康的移植器官。这说明：作者认为，对于医学来说，为病人提供健康的移置器官可能是一种福利。B说“对于人类来说，培育健康人体器官的能力无疑是一种福利”，这与作者的观点相符。文中提到human cloning时是说“克隆人可能在技术上可行，但是在法律和情感上却更加艰难；总有一天会克隆出人的”，并没有说明近年会出现克隆人，所以A不对；文中并没有提到非法之事，只是说“克隆人可能在技术上可行，但是在法律和情感方面却难以接受”，没有说克隆人是违法的，也没有说克隆任何生物是否违法，所以C和D也不对。
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