问题 阅读理解

根据短文内容,判断正(T)误(F)。

Last Sunday the Greens went to the movies. They got home very late. Father opened the front door and went into the house. It was very dark, so mother turned on the light. On the way to their bedroom, mother said, “Listen, John! I can hear someone in the bedroom. ” They all stood quietly outside the bedroom. They could hear some voices in the room.

“You are right. ” father said, “There are two men in it. They are talking. ” Then he shouted, “Who’s there?” But no one answered. Father opened the door quickly and turned on the light. The room was empty. Then father found something and laughed. “The TV is still on. I forgot to turn it off this morning!” father said.

小题1:The Greens got home very early.

小题2:On the way to their bedroom, mother heard someone in the bedroom.

小题3:They all stood quietly in the bedroom.

小题4:There were really two men talking in the room.

小题5:Father opened the door slowly and turned on the light.

答案

小题1:F

小题2:T

小题3:F

小题4:F

小题5:F

1. F                由第二句可知,格林一家很晚才到家。故此句表述错误。

2. T       在去卧室的过道上,妈妈听见有人在卧室里。此句与文意相符。

3. F        由第一段倒数第二句可知,他们都静静地站在卧室外面,而不是里面。故此句表述错误。

4. F        由第二段可知,他们听见有两人正在房间里谈话,结果发现不是真的有人在谈话,

而是电视机忘记关了。故此句表述错误。

5. F        由第二段可知,父亲迅速地打开门,然后打开灯。故此句表述错误。

实验题

就以下有关DNA研究的科学实验,回答问题:

(1)格里菲思的肺炎双球菌转化实验的结论是_________________。艾弗里实验的结论是______________。

(2)细菌转化的实质是____。

A.基因突变 B.基因重组 C.染色体结构变异 D.染色体数量变异

(3)1952年,赫尔希和蔡斯利用同位素标记法,完成了著名的噬菌体侵染细菌的实验,下图是实验的部分过程:

①.写出以上实验的部分操作过程:

第一步:用35S标记噬菌体的蛋白质外壳。如何实现对噬菌体的标记?请简要说明实验的设计方法:__________________。

第二步:用被35S标记的噬菌体与没有标记的细菌混合。

第三步:一定时间后,在搅拌器中搅拌,然后进行离心。

②.赫尔希和蔡斯用不同的放射性同位素分别标记噬菌体的DNA和蛋白质,而不是标记在同一种噬菌体上,这其中蕴涵着怎样的设计思想?______________________________。

③.噬菌体侵染细菌之后,合成新的噬菌体蛋白质外壳需要___________。

A.细菌的DNA及其氨基酸   B.噬菌体的DNA及其氨基酸

C.噬菌体的DNA和细菌的氨基酸   D.细菌的DNA及其噬菌体的氨基酸

(4)用紫外线处理大肠杆菌可诱导产生对T2噬菌体有抗性的大肠杆菌,这种抗性的产生与其细胞膜上的蛋白质发生变化有关。下图简要示意处理的方法:

①.在紫外线作用下,细菌的膜蛋白质发生改变的根本原因是______________________。

②.如何将图中的抗T2噬菌体菌株从混合菌株中筛选出来?________________________。

选择题