下列有关基因重组的叙述，正确的是（） A.基因型为Aa的个体自交

搜题请搜索小程序“爱下问搜题”

问题单项选择题

下列有关基因重组的叙述，正确的是（）

A.基因型为Aa的个体自交，因基因重组而导致子代性状分离

B.基因A因替换、增添或缺失部分碱基而形成它的等位基因a，属于基因重组

C.同源染色体非姐妹染色单体间的互换可导致基因重组

D.造成同卵双生姐妹间性状上差异的主要原因是基因重组

答案

参考答案：C

填空题

根据首字母提示拼写单词，完成下列短文。

Dear Tony,

How was your day o______(1)? Did you have fun c______(2)? I didn't have a very fun day. I

visited my cousins. It rained all day. In the morning, I s______(3)in the house and watched TV;

______(4), played computer g______(5), and read. In the afternoon, Uncle Martin put some of his

old things out in the y______(6) and had a yard sale! Unfortunately, it was kind of b______(7). No

one came to the sale b______(8) the weather was so bad.

See you soon.

Nick

选择题

Great changes ______in his hometown in the last twenty years.

A．were taken place

B．have taken place

C．have been taken place

D．took place