问题 选择题

我国科学家袁隆平培育出产量很高的杂交水稻品种,主要是利用了(  )

A.生物基因的多样性

B.生物数量的多样性

C.生物种类的多样性

D.生态系统的多样性

答案

生物多样性通常有三个层次的含义,即生物种类的多样性、基因的多样性和生态系统的多样性.基因的多样性是指物种的种内个体或种群间的基因变化,不同物种(水稻和小麦)之间基因组成差别很大,同种生物如野生水稻和普通水稻之间基因也有差别,每个物种都是一个独特的基因库.我国动物、植物和野生亲缘种的基因多样性十分丰富,为动植物的遗传育种提供了宝贵的遗传资源.如我国科学家袁隆平用野生水稻与普通水稻杂交,培育出了高产的杂交水稻,表明生物基因的多样性是培育农作物新品种的基因库.

故选:A

阅读理解

阅读理解。

     Look at the first picture, where are the children now? They are in the zoo. They are looking at the

koalas. The koalas are in a large cage (笼子). Are the koalas walking or jumping (跳跃)? They are

jumping up and down in the cage. But one koalas is not jumping. It's sleeping. It is ill (生病的).    

     Look at the second picture. Where are the children now? They are standing next to a small cage.

What's in the small cage? There is a fox (狐狸) What is the fox doing?The fox is walking in the cage. It

is looking for something to eat. It wants to go out of the cage to play and walk.    

     Look at the third picture. The children are looking at the tiger. Is the tiger sleeping? No, it isn't. It

isn't sleeping at all. The tiger is eating. What is the tiger eating? It is eating meat. There is some meat in

its mouth.

1. The children in the pictures are in the ______.

A. museum     

B. school   

C. zoo  

D. garden

2. Why is the koala not jumping? Because it is ______.

A. ill        

B. tired     

C. cazy   

D. have a rest

3. The koalas live in ______.

A. a small cage        

B. a big cage  

C. a park              

D. a room

4. What's the fox doing? It is ______.

A. walking                       

B. eating something

C. looking for food               

D. jumping

5. The tiger is eating ______.

A. chicken.      

B. bread      

C. eggs       

D. meat    

多项选择题