Same chapter3 marksDifficulty: Medium
Describe the structure of a mature human sperm.
Human Reproduction
3 marksDifficulty: Medium
What is the acrosomal reaction, and why does only one sperm fertilise the ovum?
Original Khojo Papers practice question — not from a past board paper.
Answer
When a sperm contacts the zona pellucida the acrosome releases enzymes that digest a path through it. As soon as the first sperm fuses with the plasma membrane of the ovum, the cortical granules release their contents and alter the zona pellucida so that no further sperm can bind or enter.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
This block to polyspermy is what keeps the zygote diploid.
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