MHT CET Medical202621 April 2026Evening ShiftBiologyHuman ReproductionActual
Identify the INCORRECT statement about zona pellucida.
Options
- AIt has fertilizin receptor proteins (ZP 3, ZP 2)
- BThe fertilizin binds to specific protein- antifertilizin of sperm.
- CIt brings about attraction of sperms to the egg to enhance fertilization.
- DIt stimulates acrosome to release Trypsin and Pepin
Correct answer
D. It stimulates acrosome to release Trypsin and Pepin
Step-by-step solution
The zona pellucida contains glycoproteins such as ZP1, ZP2, and ZP3. ZP3 acts as a primary sperm receptor and binds to specific proteins on the sperm head, which triggers the acrosome reaction. The fertilizin-antifertilizin interaction is a species-specific reaction where fertilizin (secreted by the egg) binds to antifertilizin (present on the sperm), facilitating the attraction and agglutination of sperms to enhance fertilization. During the acrosome reaction, the acrosome releases sperm lysins, which include hyal