LABORATORY REVIEW
MITOSIS AND MEIOSIS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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interphase 1
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metaphase 1
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prophase 1
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prophase 2
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Detailed explanation-1: -Crossing over occurs during the pachytene stage of prophase in meiosis, however the chiasma are visible during. No worries!
Detailed explanation-2: -Crossing over occurs only during prophase I. The complex that temporarily forms between homologous chromosomes is only present in prophase I, making this the only opportunity the cell has to move DNA segments between the homologous pair.
Detailed explanation-3: -In prophase, I, two copies of each gene are present on homologous chromosomes but in prophase II copies of each gene are present on sister chromatids within a single chromosome. As a result, any crossing over in prophase II would produce two identical chromatids. So the crossing over does not take place in prophase II.