The main features of sperm and eggs are -
Sperm are smaller, can swim using own tail and are produced in large numbers.
Eggs are larger, cannot swim on their own and are produced in small numbers.
In fish the female lays her eggs in the nest and swims away. The male then enters and deposits his sperm.
In mammals the male releases his sperm during sexual intercourse.
Internal fertilisation is when a sperm reaches and egg, the sperms nucleus enters the egg and fuses with the nucleus of the egg. This produces a single cell called a zygote.
External fertilisation is when the male and female come together and release their gametes into the same area.
Sperm cells are produced in the testes, the sperm is then carried away by the sperm duct.
Eggs are produced in the ovary and released into the oviduct, where fertilisation takes place.
Internal fertilisation is very important to land-living animals because land animals do not live in a watery environment, therefore there is no liquid to bring the sperm into contact with eggs. So this…