GWD13-40

cll0503

Q40:

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?

 

1. Other types of virus have surface proteins that closely resemble proteins found in various organs of mice.

2. 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.

3. Mice that are infected with a herpesvirus but do not develop keratitis produce as many antibodies as infected mice that do develop keratitis.

4. There are mice that are unable to form antibodies in response to herpes infections, and these mice survive these infections without ever developing keratitis.

5. Mice that have never been infected with a herpesvirus can sometimes develop keratitis.

这道题答案是D，俺咋觉得是C，哪位大侠解答下，谢啦。

pc123

D：有一些老鼠无法对herpes形成抗体。当这些老鼠存活下来时，他们并没有得keratitis.

C: 那些感染了herpes但是没有形成k的老鼠产生了与得了k病的老鼠一样多的抗体

实际上，C中的抗体数量与题中的论断没有任何关系。不是数量决定，而是抗体与蛋白质之间的关系决定了是否会产生k。

D提供了这么一个现象，证明如果没有抗体，就不会产生k这种病。

cll0503

为了应对病毒感染，老鼠的免疫系统通常会产生一种抗体，这种抗体通过和病毒表面的蛋白质结合而破坏病毒的生长。当老鼠感染了一种herpesvirus 的时候通常会生keratitis，一种破坏眼睛功能的疾病。由于眼球表面这种蛋白质和herpesvirus 病毒表面的很相似，因此科学家推测这些keratitis 的病例是由对抗herpesvirus的抗体引起的。

D说没有这种抗体的老鼠就不会生这种病，因此加强原文观点。

看来还是要翻译出来才明白。

Brilliance

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