Same chapter3 marksDifficulty: Medium
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3 marksDifficulty: Medium
What is crossing over, when does it occur and why does it matter?
Original Khojo Papers practice question — not from a past board paper.
Answer
Crossing over is the exchange of segments between the non-sister chromatids of a homologous pair. It occurs during the pachytene substage of prophase I of meiosis, at the chiasmata. It matters because it produces new combinations of alleles on a chromosome and is therefore a major source of genetic variation.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The enzyme recombinase carries out the exchange.
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