[Campbell Biology P.1114] Which of the following events is directly involved in preventing po... | Practice Question

Which of the following events is directly involved in preventing polyspermy after sperm-egg fusion in mammals?

  • option_a: Acrosomal reaction
  • option_b: Release of hydrolytic enzymes from the sperm head
  • option_c: Modification of the zona pellucida
  • option_d: Formation of blastomeres

Explanation

The text states, 'In mammalian fertilization, the cortical reaction modifies the zona pellucida as a slow block to polyspermy.' This is a direct mechanism to prevent multiple sperm from fertilizing the egg. The fast block is depolarization of the egg membrane. The acrosomal reaction and enzyme release are for sperm penetration. Blastomere formation is a subsequent event.