During Fertilization Polyspermy Is Prevented by?

To prevent polyspermy, the zona pellucida

, a structure that surrounds mammalian eggs, becomes impermeable upon fertilization, preventing the entry of further sperm. The structural changes in the zona upon fertilization are driven by the exocytosis of cortical granules

cortical granules

Cortical granules are regulatory secretory organelles (ranging from 0.2 um to 0.6 um in diameter) found within oocytes and are most associated with polyspermy prevention after the event of fertilization. ... Within the oocyte, cortical granules are located along the cortex, the region furthest from the cell's center.

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Cortical granule - Wikipedia

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How is polyspermy prevented during fertilization quizlet?

Polyspermy is the double fertilization of an ovum by two sperm. It is prevented by 3 methods during fertilization: 1) The intracellular wave of Ca2+ that travels across the oocyte membrane and causes hyper polarization after fusion of the sperm and oocyte membranes. ... This forms a barrier to outside sperm.

How can polyspermy be prevented?

When a sperm comes in contact with the zona pellucida layer of the ovum, it induces changes in the membrane of the ovum to block the entry of additional sperms. This, thus, prevents the polyspermy and ensures that only one sperm can fertilise an ovum.