题干

现用山核桃的甲(AABB)、乙(aabb)两品种作亲本杂交得F1,F1测交结果如下表,下列有关选项不正确的是(  )

测交类型

测交后代基因型种类及比值

父本

母本

AaBb

Aabb

aaBb

aabb

F1

乙

1

2

2

2

乙

F1

1

1

1

1

A:F1产生的AB花粉50%不能萌发,不能实现受精

B:F1自交得F2,F2的基因型有9种

C:F1花粉离体培养,将得到四种表现型不同的植株

D:正反交结果不同,说明该两对基因的遗传不遵循自由组合定律

上一题 下一题 0.0难度 选择题 更新时间:2019-02-23 05:34:34

答案(点此获取答案解析)

D

同类题2

 There are many colors in nature. But do you think that a color has weight? I think you'll say 6/no". But I'm afraid you are wrong. If you don't believe it, you may do a small experiment(实验).

  First, put two objects with the same weight into two boxes. Then cover the boxes.Third, wrap(包裹) one box with a red piece of paper, the other one with a white piece of paper. OK. Now hold the boxes with your hand one by one. It is certain that you will think the red one is a little heavier.

 Why do you think so? A scientist found that different colors have different weights in man's mind. That is to say, every color has its own weight in our mind.

 The scientist told us that colors also have smell. Can you smell the color? Of course not. Then why did the scientist say S07 That is because every color stands for (代表) a kind of light with a certain wavelength,(波长). It reaches our brain through sense organs

 According to this discovery, scientists say that people accept the colors they like, and refuse the colors they hate. So your body and mind will be healthy by using the colors you like. Or you'll be nervous or even get ill.  For example (例如) ,  you like blue and hate red.  If you stay in a room with red windows, wallpaper and furniture(家具) for two hours, you'll feel you have been there for four hours. But if the room is blue, you'll feel you have been there for only an hour.  And, if a person walks out of a blue room and into a red room, his temperature will rise.That means our body temperature will change with different colors.