2020-2021学年生物苏教版八年级下册随堂检测（8）人的性别决定
※题型：单选题※知识点：单选题※试题难度：中等<br>人的性别由性染色体决定,男性体细胞中的性染色体组成是( )<br>A.XY B.22对+XY C.X或Y D.XX<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/9/2020/d22612a0131b46b79119ad9095c0f2c3/E7F0EDF83F40244C8F0C84B97471AED6.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/9/2020/44440b88b6ee4d6891ce42a5d4b8bac5/3D9FCA8A83D96D73017D2CD32EFCF03E.png"><br><br>※题型：单选题※知识点：单选题※试题难度：中等<br>女性正常卵细胞的染色体组成为( )<br>A.23条+X B.22条+Y C.22对+XX D.22条+X<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/9/2020/62af21a96c734986bee3ed073a97865b/01A39E48B8A67989A23F6887F26FCC64.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/9/2020/d94e018d233545bf9044b9e428c3b5d9/B38FF8E27DE3605839FB282CC8F60C23.png"><br><br>※题型：单选题※知识点：单选题※试题难度：中等<br>在一个国家或地区的人口中,男女比例大致是1:1,其原因是( )<br>A.卵细胞数∶精子数≈1∶1<br>B.含X染色体的精子和卵细胞数∶含Y染色体的精子数≈1∶1<br>C.含X染色体的精子数∶含Y染色体的精子数≈1∶1<br>D.含X染色体的卵细胞数∶含Y染色体的卵细胞数≈1∶1<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/9/2020/c2fbba1a946f425883ad0489e2f72b79/D7C9A679F3C72D4F1064B7D0A0FD4AD8.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/9/2020/144e6d272d2c4a5ba1ea6c12ea6acbe0/D660F68D9D9D194ABFFCEA7081338A8A.png"><br><br>※题型：单选题※知识点：单选题※试题难度：中等<br>小明小红是亲兄妹,小明长得像父亲,小红长得像母亲,他俩染色体的正常来源是( )<br>A.一半来自父方,一半来自母方<br>B.来自父方的多,来自母方的少<br>C.来自母方的多,来自父方的少<br>D.小明主要来自父方,小红主要来自母方<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/9/2019/a4903763c93f40b0af19cbdfaf610c7b/E7F0EDF83F40244C8F0C84B97471AED6.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/9/2019/df08c0bcd86d49c39232e9586d2841ab/4BBDC9D31784BF7367E0C53A602A5230.png"><br><br>
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