问题 解答题

如图是植物细胞模式图.请据图同答问题:

(1)图中哪些结构是动物细胞所没有的______、______、______;动物细胞也具有图中的______、______、______.

(2)细胞分裂时,在④所示的结构中,______的变化最明显.

(3)结构⑥中所含有的能量转换器,除图中的叶绿体外,还应该有______.

答案

答:由图可知:①细胞壁②细胞膜③叶绿体④细胞核⑤液泡⑥细胞质

(1)植物细胞的结构有:细胞壁、细胞膜、细胞质、细胞核、液泡、叶绿体和线粒体.动物细胞有细胞膜、细胞质和细胞核、线粒体,通过比较植物细胞具有而动物细胞没有的结构是①细胞壁、⑤液泡和③叶绿体.

(2)细胞分裂时,在④细胞核所示的结构中,首先是细胞核中的染色体进行复制加倍,变成和原来形态数目相同的两份,分裂后分别进入两个细胞.因此变化最明显的是染色体.

(3)能量转换器有叶绿体和线粒体.在叶绿体内植物能进行光合作用,把光能转化为化学能储存起来,在线粒体内进行呼吸作用,在氧的参与下把有机物分解释放能量.

故答案为:(1):①细胞壁、③叶绿体、⑤液泡;②细胞膜;④细胞核;⑥细胞质

(2)染色体(3)线粒体

单项选择题

I will never forget the year I was about twelve years old. My mother told us that we would not be (16) Christmas gifts because there was not enough money. I felt sad and thought, "What would I say when the other kids asked what I’ d (17) " Just when I started to (18) that there would not be a Christmas that year, three women (19) at our house with gifts for all of us. For me they brought a doll. I felt such a sense of (20) that I would no longer have to be embarrassed when I returned to school. I wasn’t (21) . Somebody had thought (22) of me to bring me a gift.

Years later, when I stood in the kitchen of my new house, thinking how I wanted to make my (23) Christmas there special and memorable, I (24) remembered the women’s visit. I decided that I wanted to create that same feeling of (25) for as many children as I could possibly reach.

So I (26) a plan and gathered forty people from my company to help. We gathered about 125 orphans (孤儿) at the Christmas party. For every child, we wrapped colorful packages filled with

toys, clothes, and school supplies, (27) with a child’ s name. We wanted all of them to know they were (28) Before I called out their names and handed them their gifts, I (29) them that they couldn’t open their presents (30) every child had come forward. Finally the (31) they had been waiting for came as I called out, "One, two, three. Open your presents!" As the children opened their packages, their faces beamed and their bright smiles (32) up the room. The (33) in the room was obvious, and (34) wasn’ t just about toys. It was a feeling, and the feeling I knew (35) that Christmas so long ago when the women came to visit. I wasn’t forgotten. Somebody thought of me. I matter.

29().

A. reminded

B. guaranteed

C. convinced

D. promised

填空题