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 the herpes virus 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 herpes virus surface, scientists hypothesize that these cases of keratitis are caused by antibodies to the herpes virus.
Which of the following, if true, most helps to support the scientists’ reasoning?


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

Mice that are infected with the herpes virus but do not develop keratitis produce as many antibodies as infected mice that do develop keratitis.

Mice infected with a new strain of the herpes virus that has different surface proteins did not develop keratitis.

Mice that have never been infected with the herpes virus can sometimes develop keratitis.

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.

考题讲解

情景:老鼠针对病毒感染会产生一种抗体,这种抗体会附着在病毒的蛋白质表明来摧毁病毒。感染herpes病毒的老鼠会生一种叫keratitis的病(症状是眼睛会被感染)。因为herpes病毒的蛋白质和眼睛细胞的蛋白质很相似,所以科学家推测是针对herpes抗体导致了keratitis(说白了就是抗体脸盲,本来要去干掉herpes,结果误伤了眼睛细胞)。

推理:题干让我们加强“长得像 导致 误伤”这一逻辑链。

选项分析:

A选项:其他类型的病毒有和老鼠其他器官上的蛋白质相似的蛋白质:这个选项在讨论其他病毒和蛋白质,与我们的推理无关。

B选项:感染了herpes但是没有生keratitis病的老鼠和感染了herpes且生keratitis病的老鼠产生了一样多的蛋白质:这个一定程度上切断了herpes和keratitis的联系,并不能起到加强效果。

C选项:正确。一种新型的herpes病毒有着不同的蛋白质表面,感染这种病毒的老鼠就没有生keratitis病:长得不像,就没有误伤。取非之后:感染了新型herpes病毒的老鼠依旧生keratitis病,此时就切断了长得像和keratitis的关系,起到了削弱效果。

D选项:
从来没有感染过herpes的老鼠有时候会生keratitis病:切断了herpes和keratitis的联系,无法起到加强作用。

E选项:
有无法针对herpes产生抗体的老鼠,这些老鼠感染herpes
的速度与其他老鼠大致相同:无关选项。

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