- Ampullary Isthmic junction in fallopian tube.
- The perms come in contact with zona pellucida.
- Induces change in the membrane.
- blocks entry of other sperms/ensures only one sperm fertilizes the ovum prevents polyspermy.
- The secretion of acrosome helps the sperm to enter the cytoplasm.
- Entry of sperm induces completion of second meiotic division forming ovum and 2nd polar body.
- The haplaoid nucleus of sperm and that of ovum fuses.
- Formation of diploid Zygote, fertilization completed.