Pathology Upon contact between the sperm head and the zona pellucida, penetration of the sperm into the egg is allowed because of A The acrosome reaction B The zona reaction C The perivitelline space D Pronuclei formation 💡 Explanation Upon contact between the sperm head and the zona pellucida, penetration of the sperm into the egg is allowed because of ✓ Correct Answer: A. The acrosome reaction