题干

你注意过这样的现象吗?有的人将舌头两侧向上翻卷成筒状或槽状,有的人舌头则不能翻卷,其实卷舌和非卷舌是一对相对性状. 某生物兴趣小组的同学学习了遗传变异的有关知识后,选择这相对性状的遗传进行了研究. 他们向全校同学发放问卷,回收后分类统计结果如表所示:

类别

家庭数目

父母性状

子女性状

卷舌

非卷舌

第一类

89

非卷舌

非卷舌

0

89

第二类

160

非卷舌

卷舌

104

56

第三类

120

卷舌

卷舌

97

23

上一题 下一题 0.0难度 选择题 更新时间:2018-10-16 08:01:19

答案(点此获取答案解析)

同类题5

任务型阅读

    If you want to keep fit, please refer to the following:

    Move More

    Make it a daily habit to find ways to move your body.____ Climb stairs instead of taking the lift. Walk your dog; play with your kids. It doesn't have to be an hour in the gym or a 45-minute dance class. But that's great when you're up to it. At the same time, move more.

    Give up Smoking

    Ever since 1960 when it was announced that smoking was harmful to health, Americans have been reducing their use of tobacco products. Just recently, we've seen more and more teens smoking. Could it be the Hollywood influence?____Take care! Warn your children against smoking.

    ____

    While recent studies show a glass of wine or one drink a day can help protect against heart disease, more than that can cause other health problems such as liver and kidney disease and cancer.

    Reduce Stress

    Easier said than done. Stress comes in many ways.____Spend 30 minutes a day doing something you like such as walking on the beach or in a park, reading a good book, visiting a friend, listening to relaxing music, and watching a funny movie.

    Protect Yourself from Pollution

    If you can't live in a smog-free environment, at least avoid smoke-filled rooms.____Exercise indoors in air conditioning when air quality is good.

A. Avoid Overdrinking

B. There are many things you can do to move your arms and legs.

C. Think carefully before doing something.

D. Exercise outside when the smog(雾霾)rating is low.

E. It seems that the stars in every movie smoke cigarettes.

G. It's important to reduce it.