问题 填空题 案例分析题

科学家研究发现一种树突状细胞(DC细胞),能参与人体的免疫的过程(如下图示意),请回答下列问题:

艾滋病病毒(HIV)通过T淋巴细胞表面的特异性CD4受体识别T淋巴细胞并侵染,从而破坏人类免疫系统。科学家正在研究将病毒引诱到能导致其死亡的人体“陷阱”细胞中,以防止病毒增殖。研究思路是:建构HIV可识别的带有CD4受体的人体()细胞,让HIV识别并侵染,侵染这种细胞后的HIV病毒却无法增殖。请简要说明HIV在这种“陷阱”细胞中无法增殖的原因()

答案

参考答案:成熟的红;成熟的红细胞无细胞核等结构,HIV病毒的遗传物质无法扩增,蛋白质也无法合成

解析:

(1)DC细胞处理抗原后,细胞外出现特定的结构能与T细胞有识别作用的受体相结合,激活信号分子(S1、S2)从而激发T细胞出现免疫效应,此过程体现细胞膜信息交流的功能。

(2)T细胞发生免疫效应时,它产生的淋巴因子可刺激B细胞增殖分化;效应T细胞也能直接作用于被抗原入侵的靶细胞,发生细胞免疫。

(3)由图知,DC细胞在免疫调节中的具体功能是吞噬、处理并呈递抗原。

(4)免疫调节不仅积极应对外来抗原的入侵,同时也随时应对体内的异常细胞,这体现了免疫系统的防卫、监控、清除功能。

(5)研究思路是:建构HIV可识别的带有CD4受体的人体成熟的红细胞,让HIV识别并侵染,侵染这种细胞后的HIV病毒却无法增殖。HIV在这种“陷阱”细胞中无法增殖的原因:成熟的红细胞无细胞核等结构,HIV病毒的遗传物质无法扩增,蛋白质也无法合成。

考点:本题考查免疫调节,意在考查考生能理解所学知识的要点,把握知识间的内在联系,形成知识的网络结构。

单项选择题
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     Sometimes children do not do what their parents tell them to do. When this happens, a parent tries to

help the child to do the right thing. When this does not work, the parent usually punishes the child.

     There are many things that a parent can do. One thing that people have done is to spank (打屁股) the child. When a parent spanks a child, they will use their hand or a hard object to strike them on their

bottom. This is meant to show the child that they have done something wrong.

     One parent remembers being spanked when he was a child. His parents used a wooden spoon. When he spanked his own children with his hand, he saw that he put a red mark on his child's leg. He never did

that again.

     One problem with spanking is that it teaches the child to hit someone when they do not like what the

other person is doing. Another problem with spanking is that the parent is usually angry and can hit the

child too hard. Sometimes parents will use spanking for everything and not try other ways to get the child

to do the right thing.

     Many parents are not sure of what to do instead of spanking. Some people think that their religion(宗教)tells them that spanking is okay. Some think that the law lets them do it. The courts (法院) say that

parents have the right to teach their children how to behave.

     Other things should be tried before a parent decides to spank a child. Telling the child exactly what is

wanted from them can be one thing. Giving a child more than one choice is another thing that can be tried. Getting down to the child's level and taking a more child-friendly approach (方法) can help as well.

1. According to the passage, when children do something wrong, one thing that parents usually do to

punish them is to ________.

A. strike them on the bottom

B. try to help them do the right thing

C. teach them what to do

D. take them to court

2. Which of the following is NOT the problem caused by spanking?

A. It teaches the child to hit others when they offend him or her.

B. The parent may get angry and hit the child too hard.

C. Sometimes parents may use spanking for everything.

D. It makes parents try other ways to make the child do right.

3. Which of the following can best describe the writer's attitude towards spanking?

A. favorable (赞同的)

B. indifferent (不关心)

C. interested

D. unfavorable

4. From this passage, we can conclude that ________.

A. Good children always do the right thing.

B. Parents should try their best to avoid spanking their children.

C. Parents have no choice but to spank their children when they do something wrong.

D. Children can have more than one choice to avoid being spanked.