题目

 Have you ever hear a saying, “Never judge a book by its cover.”? This is a good rule to follow when trying to judge the intelligence of others. Some people have minds that shine only in certain situations. A young man with an unusual gift in writing may find himself speechless before a pretty girl when he speaks. He may not be able to find the right words. But don’t make the mistake of thinking him stupid. With a pen and paper, he can express himself better than anybody else.    Other people may fool you into overestimating their intelligence by putting up a good front. A st某生物兴趣小组的同学，对部分家庭的耳垂遗传情况进行调查．如表是他们的调查结果，请分析数据，并结合所学知识回答问题． 组别 父亲 母亲 家庭数目 子女有耳垂数 子女无耳垂数 A 有 无 342 271 106 B 有 有 527 397 167 C 无 无 201 0 233（1）表格中所涉及的有耳垂与无耳垂，在遗传学上称为 ．（2）根据表中第 组的调查结果可以推断无耳垂是隐形性状．如果控制显性性状的基因用D表示，控制隐性性状的基因用d表示，在第C组家庭中，母亲的基因组成是 （3）在第B组家庭中的一对夫妇，第1个孩子无耳垂，该夫妇再生一个孩子无耳垂的几率是 %，这个孩子是男孩的可能性是 %．