下列有关基因突变的叙述中，正确的是_刷题宝

题干

下列有关基因突变的叙述中，正确的是（）

A：自然状态下的突变是不定向的，而人工诱变多是定向的

B：基因突变既可自发产生，也可由环境因素诱发

C：基因突变的普遍性是指基因突变可以发生在生物个体发育的任何时期

D：由于细菌的数量多、繁殖周期短，因此其基因突变率很高

上一题下一题 0.0难度选择题更新时间:2013-12-23 07:14:03

答案(点此获取答案解析）

B

同类题1

Hangzhou is distinguished its beautiful scenery.

同类题2

下列各组化合物中全是内环境成分的是（）

同类题3

阅读短文，选择最佳答案。

A

Look! This is a picture of my teacher's family. This is Mr. Smith. He is my English teacher. His wife is a doctor. She is nice. They have a son and a daughter. The boy's name is Sam and the girl's name is Kate. They are students. They are in the same school. They go to school on their bikes. Look! The son is like his mother. The daughter is like her father. Now they are all in China and can speak Chinese. They love China.

同类题4

同类题5

下列各组词语中划线字的读音，全都正确的一项是（）

小学学科试题库

初中学科试题库

高中学科试题库