问题 问答题 简答题

细胞核的结构及其主要生理机能是什么?与细胞质有何联系?

答案

参考答案:

细胞核的基本结构包括核膜、核液、核仁、染色质等。

核膜对控制内外物质的出入,维持核内环境的恒定有重要作用;核仁的主要机能是合成核蛋白体;而染色质可形成染色体,在染色体上具有大量控制遗传性状的基因。

那么细胞核的机能主要就是保存遗传物质,控制生化合成和细胞代谢,决定细胞或机体的性状表现,把遗传物质一代一代传下去。细胞核和细胞质是相互作用、相互依存而表现出细胞统一的生命过程。

细胞核控制细胞质;细胞质对细胞的分化、发育和遗传也有重要作用。

选择题
完形填空

It was a dark night. I saw bright light in my neighbor,Jack’s kitchen. I thought he could be having a midnight snack, so I went back to my bed. Soon, there was a burning smell and I thought something must be wrong. At once, I jumped out of bed and went downstairs to have a look. I saw a fire coming out of my neighbor’s kitchen. I shouted “Fire!” But there was no one nearby to hear my shouts for help. I ran quickly into my house and called the Fire Department and went back to my neighbor’s house. I knocked at the door and called my neighbor’s name, but there was no answer. I tried to break into the house and saved a cat and a rabbit. I tried to pour water through the kitchen window but it was no use. The fire was too big. Luckily, a fire engine arrived and the firemen put out the fire.

When my neighbor came back, he was sad because his kitchen was burnt down, but he thanked me for calling the Fire Department and for saving his pets.

Several weeks later, my neighbor invited me to his home for dinner. At his new kitchen, he took a photo for me. Later on, he gave me the photo as a present. It made me very happy.

根据文章内容,回答下列问题。(10分)

1. Where did the fire happen?  

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2. Why did the writer run quickly into his house?

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3. What did the writer save from the fire?

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4. Who put out the fire?  

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5. What did Jack do several weeks after the fire?

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