题干

某同学在实验室中做“植物细胞的吸水和失水”实验时,在实验室老师的帮助下,进行了一系列的创新实验,实验步骤和现象如下表,对上表的推断或解释不正确的是(  )

实验组

5分钟的现象

再过5分钟

滴加清水5分钟

0.3g•mL1蔗糖溶液

x

无变化

质壁分离复原

0.5g•mL1蔗糖溶液

质壁分离

y

无变化

1mol•L1KNO3溶液

质壁分离

质壁分离复原

z

1mol•L1醋酸溶液

无变化

细胞大小无变化

细胞大小无变化

A:x为质壁分离,因为细胞壁伸缩性高于原生质层

B:y为质壁分离,可能导致细胞失水过多而死亡

C:z为细胞稍增大,细胞液颜色变浅

D:④组无变化是因为细胞吸水量等于失水量

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答案(点此获取答案解析)

A,D

同类题4

根据短文内容,从短文后的A—G选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

    Many of us deal with the rush every morning in preparation for work or school, but it doesn't have to be this way. With a little time management, these steps can help you cut down on your morning stress.

Create an evening preparation routine

    ____ These simple tasks will take you less than 30 minutes to complete each evening and will save you a huge headache every morning.

Get a good night's sleep

    Make sure you go to bed at a reasonable hour to allow enough time for a healthy night's sleep. Most people require between seven and eight hours' sleep each night. If needed, set a bedtime reminder alarm on your alarm clock.____

Wake up 30 minutes earlier

    An extra 30 minutes in the morning will make a difference. As long as you get to bed on time, waking up 30 minutes earlier should seem natural after just a few days.____

Plan a realistic day

    Writing things down means you don't have to worry about forgetting to do them.____ Write down anything that cannot be put off to following day.

____

    Getting up to face a new day is far more satisfying when you have something to look forward to. Make sure you manage your time better so that you have time to do something you love on a daily basis.

A.Morning stress is very common.

B.Schedule something you love daily.

C.Never fill your mind with unnecessary worries.

D.Make a summary of what you did in the daytime.

E.Use this time to think, shower and eat breakfast.

F.Iron your clothes, locate your keys, plan a nutritious breakfast, etc.

G.Always keep the temperature in your bedroom comfortably cool.