问题 填空题 案例分析题

人的耳朵有的有耳垂,有的无耳垂。某医学小组调查了人群中有耳垂性状和无耳垂性状的遗传情况,统计情况如下表:(控制耳垂的基因用A、a表示)

在第一组的抽样家庭中,双亲的基因型组合方式可能是什么?

答案

参考答案:AA×AAAA×AaAa×Aa

解析:分析表格,可根据第一组的情况推出显隐性。因双亲均为有耳垂,后代出现了无耳垂的情况,可知有耳垂为显性,无耳垂是隐性。婚配方式有6种,分别是AA×AAAA×AaAa×Aaaa×aaaa×AaAA×aa。第二组中类似测交,所以父亲的基因型是Aa。考点:基因的分离定律点评:本题综合考查学生对基因分离定律的掌握和理解,培养学生理论联系实际的能力,帮助学生深化理解该定律。

阅读理解

For many people of Norway(挪威),skiing(滑雪) is the best way to have fun in winter. Almost everyone can ski. Children learn to ski after they learn to walk. Long long ago in Norway, there were no buses, trains or cars. People had to find a way to walk over the deep snow. Skis were the right answer!

Although they love winter, the people of Norway are also happy to see summer come. They enjoy the out-door activities at any time of the year. In summer they swim and sunbathe near the beach. Some people go cycling and go mountain climbing. Sail-boating is also very popular during the warm sunny summer months.

The Norwegians(挪威人), like people everywhere, find many in-door ways to have a good time. During the long winter they also enjoy movies. They like to read books from the libraries in all seasons. Family life is very important to the people of Norway.

小题1:In winter, _______ is the most popular sport for Norwegians to have a good time.

A. skiing                  B. skating             C. climbing

小题2: Long long time ago, Norwegians skied to ________.

A. have fun                B. keep fit           C. cross the deep snow

小题3:We can find _________ kinds of outdoor activities in the passage.

A. 5                       B. 6                    C. 7

小题4:From the passage we know __________.

A. Norwegians like winter, but they don’t like summer.

B. Norwegians don’t think family life is very important.

C. Norwegians also like indoor activities.

小题5: The writer wants to tell us about Norwegians’ _________.

A. sports                  B. life                    C. habits

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