Fertilisation

• Fertilisation

  1. Sperm head meets the protective jelly layer around the egg cell called the zona pellucida

  2. Acrosome reaction occurs - enzymes digest the zona pellucida

  3. Sperm head fuses with the cell membrane of the egg cell, allowing the sperm nucleus to enter the egg cell

  4. Cortical reaction occurs, causing the zona pellucida to harden and prevent polyspermy

  5. Nuclei fuse, restoring a full set of chromosomes and forming a diploid zygote