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题型:实验探究题 题类:常考题 难易度:普通

山东省滨州市五校2020-2021学年七年级上学期生物第一次月考试卷

某些媒体报道“转基因植物油对人类的健康不利”,也有专家说“转基因植物油是安全的”,到底是否安全呢?某学生针对这一问题进行了如下探究实验。

( 一 )实验器材:普通大豆油,转基因大豆油,稻谷若干,小白鼠若干,两个规格一样且空间足够大的铁笼等。

( 二 )该同学提出的问题:转基因大豆油对人类的健康是否有影响?

( 三 )实验过程:

( 1 )将两个铁笼分别贴上甲组和乙组标签,选取两只身体健康状况良好、大小一致、性别相同的小白鼠,分别置于甲、乙铁笼中。

( 2 )称取一定重量的同种稻谷平均分成两份,分别拌适量且等量的普通大豆油(A料)和转基因大豆油(B料)待用。

( 3 )甲组饲喂适量A料,乙组饲喂B料。 

( 4 )饲喂一段时间后,观察并记录甲、乙两组小白鼠的生长状况。

( 5 )预测实验结果和结论:

①若两组小白鼠的生长状况有明显差异,则说明转基因大豆油对人类健康(填“有”或“无”)影响。 

②若两组小白鼠的生长状况无明显差异,则说明转基因大豆油对人类健康(填“有”或“无”)影响。 

( 6 )请根据上述实验设计回答下列问题:

①探究实验中该同学未提出假设,请你为该同学写出假设,你的假设是:。 

②该同学设置甲组的目的是,该实验的实验变量是。 

③该实验选取小白鼠的数目过少,会增大实验的,导致实验结论可信度不高。

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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