题目

阅读下面短文，在空白处填入 1个适当的单词或括号内单词的正确形式。The giant panda 【1】 (love) by people throughout the world. Chinese scientists 【2】 (recent) had a chance to study a wild female panda with a newborn baby. She was a very 【3】(care) mother. For 25days, she never left her baby, not even to find something 【4】 (eat)! She would not let any other pandas come near. She licked the baby constantly to keep it clean. Any smell might attract natural 【5】(enemy) that would try to eat the little comforting pats. The mother held the baby in her fro下列说法正确的是（    ）       ①生物的性状是由基因控制的，生物的性别也是由性染色体上的基因控制的       ②属于XY型性别决定类型的生物，雄性体细胞中有杂合体的基因型XY，雌性体细胞中有纯合体的基因型XX       ③人类色盲基因b在X染色体上，Y染色体上既没有色盲基因b，也没有它的等位基因B       ④女孩是色盲基因携带者，则该色盲基因是由父方遗传来的       ⑤男人色盲不传儿子，只传女儿，但女儿不显色盲，却会生下患色盲的外孙，代与代之间出现了明显的不连续现象       ⑥色盲患者男性多于女性[来源:ZXXK]       A．①③⑤                B．②④⑥              C．①②④                D．③⑤⑥