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

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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 Wilmut 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. "
Which of the following is true according to the text?

选项 A、The principle of gene therapy is applicable to that of cloning.
B、The isolation of stem cells is too difficult to be feasible.
C、It is reasonable for all body instructions to be activated.
D、Cloned animals will eventually take control of the world.

答案A

解析 细节题。文章第五段中第一句讲到”适用于克隆(the same applies to cloning)”,由上文可知“基因治疗的原理适用于克隆”。文章的第四段讲到干细胞的分离的确可以实施,尽管无法控制,B项”干细胞的分离太难而不可能实施”与文章矛盾。文章第二段第一句作者说不能把所有的身体干细胞都激活,而且这是很有道理的,C项”所有的身体指令都激活,这是相当有道理的”与文章不符。D项讲到”克隆动物将最终控制世界”,尽管原文讲到有大量克隆动物存在,但并没有提到这样的观点。
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