本题目来源于试卷: Continuity and Change D.4 Cell & Nuclear Division,类别为 IB生物学
[单选题]
Which stage of meiosi -1i5on79bx evii8 unds is matched to the correc;dfwu g4/wz 8rt description?
A. Stage is Anaphase I;Description is Sister chromatids are pulled to either side of the cell.
B. Stage is Metaphase II;Description is Homologous chromosomes align at the equator of the cell.
C. Stage is Prophase I;Description is Crossing over between non-sister chromatids occurs.
D. Stage is Telophase I;Description is Four haploid nuclei are formed.
参考答案: C
本题详细解析:
During prophase I, homologous chromosomes pair up and crossing over can occur between non-sister chromatids at sites called chiasmata (chiasma singular) (Choice C). During Anaphase I, homologous chromosomes are pulled to either pole of the cell; thus, Choice A is incorrect. During Metaphase II, chromosomes align on the cell's equator; thus, Choice B is incorrect. During Telophase I, two nuclei are formed; thus, Choice D is incorrect.
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