Question

The main function of the multiple cortical granules released from the oocyte into the perivitelline space is -

• A. Aid in the entry of 2 sperm into the ovum to form fraternal twins
• B. Prevent binding of additional sperm
• C. Activate special receptors to which sperm attaches
• D. None of the above

Answer 1

The correct option is B

Prevent binding of additional sperm

Soon after the first sperm penetrates the zona pellucida of the ovum, calcium ions diffuse inward through the oocyte membrane triggering multiple cortical granules to be released by exocytosis from the oocyte into the perivitelline space. These granules contain substances that permeate all portions of the zona pellucida and prevent binding of additional sperm.