题干

三联苯 的一氯代物有(   )

A:2种

B:3种

C:4种

D:5种

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答案(点此获取答案解析)

C

同类题4

研究人员依靠体细胞克隆技术进行反复“拷贝”,成功培育出第四代克隆猪.这个研究小组培育的第一代克隆猪于2004年4月诞生,此后,他们又从长大的克隆猪唾液腺中提取细胞,将细胞核植入未受精的卵细胞中,依次培育出第二代和第三代克隆猪.克隆猪可作为研究人类疾病的实验动物.根据材料回答下列问题:

(1)克隆的实质就是____;克隆技术是利用了动物____的全能性.

(2)在细胞核植入受体卵细胞之前,要用显微针去除卵细胞的细胞核,再将唾液腺细胞核注入.在体细胞核移植技术中人们往往以成熟卵细胞作为受体,原因是____

(3)获得的重组细胞需要体外培养,培养时不仅要有无机盐类、维生素、氨基酸、核苷酸等营养成分及激素、动物血清,而且还要适宜的温度、pH、气体环境以及无菌无毒的环境等.要用物理或化学方法去激活受体细胞,目的是使其完成____,当它发育到囊胚期时,将其移植到受体雌性动物的____ 内.

(4)利用克隆技术根本无法培育出完全相同的个体,究其原因,除了发育过程中的环境因素的影响外,还可能受____中遗传物质的影响,或发生基因突变.

(5)下列选项中____ 属于在分子水平上取得的生物学成果.

A.人类基因组草图    B.试管婴儿    C.克隆羊多利    D.杂交水稻.

同类题5

阅读下列短文,根据短文内容,从短文后各题所给的A、B、C、 D四个选项中,选择最佳选项。

SCENE I

One dollar a week

The doorway of the house where Chandler has a room. He is dressed in his best clothes, ready for his evening out. He is going out as his friend, Jeff White, comes in.

WHITE         What are you doing this evening, Towers?

CHANDLER      (Smiling) Tonight I'm going to live like a man with a million dollars!

WHITE         What are you talking about? You haven't got a million dollars!

CHANDLER      How much money are you and I paid each week, Jeff?

WHITE         Eighteen dollars. Why?

CHANDLER      And how much of that eighteen dollars do you spend each week?

WHITE         All of it, of course.

CHANDLER    Well, I don't. Each week I save one dollar out of my eighteen. Then, every ten weeks, I can buy myself an evening to remember.

WHITE         What do you do?

CHANDLER   I put on my finest clothes, go to one of the best restaurants in New York, eat the most expensive food on the menu, drink the best wine, and then take a taxi home!

WHITE          (Surprising) Why?

CHANDLER     Why? Because it makes me feel wonderful to sit with some of the richest people in America, and to make them think that I'm rich, too.

WHITE          You're crazy!

CHANDLER     (Laughing) Perhaps I am!

Mrs Black comes in.

MRS BLACK      Ah, Mr Chandler. I wanted to see you.

CHANDLER      Good evening, Mrs Black. What a lovely evening!

MRS BLACK   Lovely evening perhaps, but you haven't paid me for your room this month. When am I going to get the money?

CHANDLER     Soon, Mrs. Black. Very soon.

Mrs Black looks at Chandler's clothes.

MRS BLACK      You can spend money on expensive clothes, but you can't pay for your room. Is that right?

CHANDLER    (Hurrying away) Good night, Mrs Black!