CELL DIVISION
MEIOSIS AND GENETIC VARIATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Prophase I
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Metaphase I
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Anaphase I
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Telophase I
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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 is an enzyme-mediated process, where the exchange of genetic material between non-sister chromatids of homologous chromosomes takes place. It occurs at the pachytene stage of prophase I of meiosis.
Detailed explanation-3: -Explanation: During prophase I, homologous chromosomes pair with each other and exchange genetic material in a process called chromosomal crossover. The exchange occurs in segments over a small region of homology (similarity in sequence, ie., the same alleles).
Detailed explanation-4: -During meiosis, crossing-over occurs at the pachytene stage, when homologous chromosomes are completely paired. At diplotene, when homologs separate, the sites of crossing-over become visible as chiasmata, which hold the two homologs of a bivalent together until segregation at anaphase I.