题干

右图是某校学生根据调査结果绘制的半乳糖血症的家系图(显、隐性基因用A、a表示),调查中同时发现仅II4患有红绿色盲(基因用b表示)。下列分析不正确的是(    )

A:半乳糖血症是常染色体隐性遗传病

B:II6为色盲基因携带者的概率为1/4

C:III9 的基因型为 AAXBY 或 AaXBY

D:若III9和III10近亲婚配,生下患病孩子的概率是3/8

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B

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    I've loved my mother's desk since I was just tall enough to see above the top of it when Mother sat doing letters. Looking at the ink bottle, pens and white paper, I decided that the act of writing must be the most wonderful thing in the world.

    Years later, during her final illness, Mother kept different things for my sister and brother, “But the desk,” she said again, “is for Elizabeth.”

    I never saw her get angry, and never saw her cry. I knew she loved me, and she showed it in action. But as a young girl, I wanted heart-to-heart talks between mother and daughter. They never happened and a gulf opened between us. I was “ too emotional (易动感情的) ”, but she lived “on the surface”.

    As years went by, I had my own family. I loved my mother and thanked her for our happy family. I wrote to her in careful words and asked her to let me know that she did forgive (原谅) me.

    I posted the letter and waited for her answer, but it didn't come. I wondered if the letter had even got to her. I only knew that I had written it, and I could stop trying to make her into someone she was not.

    Now the present of her desk told me that she was pleased that writing was my chosen work, though she had never been able to. I cleaned the desk carefully and found some papers inside … a photo of my father and a one-paper letter, folded (折叠) and refolded many times.

    Give me an answer, my letter asks, in any way you choose. Mother, you always chose the act that speaks louder than words.