Gametes and fertilisation

Humans typically reproduce through sexual reproduction. Sexual reproduction produces offspring that are unique individuals. Half of their genes come from each parent.


Gametes are the sex cells:

  • eggs are female gametes
  • sperm are male gametes

Gametes have adaptations to increase the chances of fertilisation and successful development of an embryo. For example, sperm cells are produced in large numbers to increase the chance of fertilisation. Sperm cells have these adaptations:

  • a tail to move them towards an egg cell
  • many mitochondria to provide energy
  • an acrosome (part of the tip of the head) that releases enzymes to digest the egg membrane


In sexual reproduction, a male gamete and a female gamete join together. This is fertilisation.