GWD23--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?

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.

     Answer: D

不明白，我首先就把D給排除了，覺得是削弱。最后選了C。麻煩給個解釋啊。完全糊涂中。

首先解釋老鼠透過產生抗體對抗殺死病毒，方法是用蛋白質包覆在病毒表面，

得病老鼠同時會發生一種疾病,因為在眼部細胞表面的蛋白質與病毒表面蛋白質

相當類似，所以科學家斷定眼部疾病是抗體對抗H病菌產生的後遺症

解題關鍵在於是否沒產生抗體就不會有這種後遺症，取反面的例證就形成支持。

一個簡單的例子：吃很多東西就會胖，一種支持這種說法就是不吃東西果然不會胖

恩。明白了。

antibodies+protein---------destroy virus(在這里就是herpes virus）---------keratitis，protein有了，還差antibodies,如果沒有antibodies,那么自然就沒有keratitis。

可是……我一看這題目我就暈了，考試的時候肯定反應不過來啊