如果……CGUUUUCUUACGCCU……是某基因产生的mRNA中一个片段,如果在该

题型:单项选择题

问题:

如果……CGUUUUCUUACGCCU……是某基因产生的mRNA中一个片段,如果在该RNA序列中某一位置增添了一个碱基,则表达时可能发生:()

①没有变化

②肽链中氨基酸序列全部改变

③肽链延长

④肽链提前中断

⑤不能表达出肽链

A.①②③④⑤

B.①②③④

C.①③⑤

D.②④⑤

考点:高中生物基因重组与基因突变基因重组与基因突变题库
题型:单项选择题

如图所示的四种粒子的结构示意图中,说法正确的是(  )

A.它们表示四种不同的元素

B.②表示的元素在化合物中通常显+2价

C.①③④表示的元素都是非金属元素

D.①④表示的是阳离子

题型:单项选择题

阅读理解。

     Do people in your country hug and kiss on the street? In some countries, it is common for people to

show affection (喜爱) in public places. In the United States, for example, we often see couples hold hands,

hug or kiss on the street, in the park, in restaurants, and even on trains and buses! However, in some other

countries, people never show affection in public places because their customs don't allow this. For example,

in China and Korea, custom doesn't allow people to do so in public. So, when Chinese and Korean people

visit the United States, they often feel very surprised and shocked when they see Americans hug and kiss on

the street. In some countries friends show physical affection to each other.

     In some South American countries, female (女性) friends walk arm in arm when they walk along the

street together. In Italy and Russia, male friends often kiss each other on both cheeks when they greet. In

most countries, men don't kiss or hug when they greet another. They usually shake hands or pat each other

on the back.

    People around the world are different in amount, manner, and situations in which they touch each other.

1. How do Korean people feel when they see people kiss and hug on the street?

A. Worried and sad.

B. Happy and interested.

C. Relaxed and enjoyable.

D. Surprised and shocked.

2. What's the Chinese meaning of  'hug' in the passage?

A. 拥抱

B. 摔跤

C. 嬉戏

D. 鞠躬

3. According to the passage, which of the following is NOT true?

A. Social customs are different in different countries.

B. Customs in the United States allow public affection.

C. Women in South America never touch each other.

D. People around the world are different in some ways in which they touch each other.

4. From the passage we can know that ________.

A. it is not polite to hug and kiss in public

B. male friends in Russia often kiss each other on both cheeks

C. Chinese and Korean people don't hug and kiss each other

D. all Americans like to kiss

5. The main idea of this passage is that _________.

A. Chinese people are quite different from American people

B. Koreans and Americans can never understand each other

C. different culture allows different ways to show affection

D. people in some countries are more affectionate than those in some other countries

题型:单项选择题

锌的核电荷数为30,其最外电子层上只有2个电子,常显+2价。据此,请画出锌离子的结构示意图。

题型:单项选择题

患儿男性,7个月,因“腹泻3天”来诊。患儿每天排粪5~6次,稀水便,夹有不消化奶瓣,无黏液及脓血,无发热,稍有烦躁哭闹,尿量轻微减少。查体:意识清,反应稍差,眼窝稍凹陷,皮肤弹性尚可,肢端尚温暖,脉搏、血压正常。粪常规:稀水便,无红细胞、白细胞。

该患儿的诊断是()

A.急性肠炎

B.消化不良性腹泻伴轻度脱水

C.消化不良性腹泻伴中度脱水

D.消化不良性腹泻伴重度脱水

E.消化不良性腹泻

题型:单项选择题

国际工程投标报价工作在投标者通过资格预审并获得招标文件后开始,其工作程序为组织投标报价班子、研究招标文件、进行各项调查研究、参加标前会议和现场勘察、工程量复核、生产要素与分包工程询价等环节。

( )是投标获得成功的基本保证。

A.进行各项调查研究

B.研究招标文件

C.组织一个水平高的投标报价班子

D.核算工程量

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