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标题: gwd-23-22 [打印本页]

作者: cournot 时间: 2006-7-3 11:13
标题: gwd-23-22

Q22:

In response to viral infection, the immune systems of mice typically produce antibodies that destroy the virus by binding to proteins on its surface. Mice infected with a herpesvirus generally develop keratitis, a degenerative disease affecting part of the eye. Since proteins on the surface of cells in this part of the eye closely resemble those on the herpesvirus surface, scientists hypothesize that these cases of keratitis are caused by antibodies to herpesvirus.

Which of the following, if true, gives the greatest additional support to the scientists’ hypothesis?

Other types of virus have surface proteins that closely resemble proteins found in various organs of mice.
There are mice that are unable to form antibodies in response to herpes infections, and these mice contract herpes at roughly the same rate as other mice.
Mice that are infected with a herpesvirus but do not develop keratitis produce as many antibodies as infected mice that do develop keratitis.
There are mice that are unable to form antibodies in response to herpes infections, and these mice survive these infections without ever developing keratitis.
Mice that have never been infected with a herpesvirus can sometimes develop keratitis.

这个题目哪位帮我分析一下？

作者: lismiles 时间: 2006-7-3 15:50

我选D

老鼠的免疫系统产生一种抗体，这种抗体能够附着在蛋白质上破坏病毒。感染了H的老鼠通常会得K，一种眼病。由于有K眼病的眼细胞表面上的蛋白质与H表面得蛋白质非常相似，科学家猜想K病是由于H的抗体引起的。问：那个加强？

D 确实有一些感染了H但没有产生抗体的老鼠，这些老鼠没有得K病而活了下来。

作者: gonghao 时间: 2006-7-3 15:53

C说发不发病都有那么多抗体，哪抗体就不是原因了，题目要求的是support，支持是抗体造成的。所以C不能选。

D：没有抗体不发病，结合题目说有抗体就发病

则说明就是抗体造成的发病，从而支持科学家的假说

作者: cournot 时间: 2006-7-4 07:03
谢谢两位！

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