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题型:实验探究题 题类:常考题 难易度:普通

安徽省滁州市南谯区2020-2021学年八年级下学期生物期中考试试卷

小山发现年糕很容易发霉,为了探究年糕发霉的原因,他设计了实验:他先将一块年糕切成大 小相同的三块,分别放入甲、乙、丙三个大小相同的玻璃瓶里,然后将瓶口用软木塞塞住,用蒸 汽灭菌锅进行处理。最后,他把甲瓶的塞子打开,放置在室温下;乙瓶的塞子不动,放置在甲 瓶附近;将丙瓶的软木塞打开,放在甲瓶附近但设法使丙瓶的温度维持在4C左右。几天以 后,他发现,甲瓶里的年糕出现大量霉斑,乙瓶里的年糕没有发霉,丙瓶里的年糕少许发霉。 请根据实验回答下列问题:
(1)、实验中,进行高温处理的目的是
(2)、该实验共设置了组对照实验,当瓶和瓶作为对照时,变量为瓶子是否封闭;当甲瓶和丙瓶作为对照时,变量是。乙瓶和丙瓶(选填“是”或“不是”)对照实验,因为
(3)、分析甲瓶和乙瓶的现象可知,年糕发霉变质的原因是中的微生物在年糕上生长繁殖引起的。
举一反三
选取三枝同一植物的长势相同的枝条分别标记为A、B、C, 作如下表的处理后,分别插入相同大小的、盛有等量蒸馏水的量筒中,并以石蜡油覆盖密封水面,置于适宜环境条件下。2小时后观察记录各组量筒中蒸馏水的减少量(说明:涂抹凡士林能堵塞叶片相应部位气体进出的通道)。请回答下列问题:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 

枝条编号

枝条处理

蒸馏水减少量

A

不作任何处理

2mL

B

凡士林涂抹所有叶片下表面

0.5 mL

C

除去枝条上的所有叶片

0 mL

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