问题 选择题

组织形成的过程大致是                 (    )

A.细胞分裂→细胞分化→细胞生长

B.细胞分裂→细胞生长→细胞分化

C.细胞生长→细胞分化→细胞分裂

D.细胞分化→细胞分裂→细胞生长

答案

答案:C

题目分析: 组织形成是细胞分化的结果。生物体内都有终生保持分裂能力的细胞,不断分裂使生物体长大,但分裂产生的新细胞中除一小部分保持分裂能力,大部分丧失了分裂能力,在生长过程中形态结构发生了不同的变化,而形态结构相似,功能相同的细胞联合在一起,组成的细胞群叫组织。如植物的保护组织,输导组织,人体的上皮组织,肌肉组织等。所以组织形成的过程是细胞分裂→细胞生长→细胞分化→组织。

考点: 细胞分化形成组织。

阅读理解

根据短文内容,判断对"√" "×"。

                                                                   A Letter

Dear Mother,

     I'm writing to you from our hotel at Golden Beach. Jim and I are on vacation with the children for

a week, we aren't happy. We are having some problems.

    The weather isn't good. It's cold and cloudy. Now I'm looking out of the window and it's raining

cats and dogs.

    Tony and Tommy aren't very happy. They are having a terrible time. They

can' t play outside. They are sitting on the bed. playing cards and watching TV.

     Jim is at the doctor's office . He has got a headache.

     We are going to be back on Thursday.

     See you soon.

                                                                                                                                             Love,

                                                                                                                                             Ethel   

( )1. Ethel and Jim are on their vacation.

(     )2. The children are very happy.

(     )3. There are many cats and dogs out of the window.

(     )4. Tom and Tommy are playing outside.

(     )5. Ethel has got a headache.

单项选择题