Two parents are needed in sexual reproduction. During this process the nuclei of the male and female gametes are fused in order to create a zygote. This process is known as fertilisation. The gametes contain half the number of chromosomes (they are haploid). When the male and female gametes combine, they create the full complement of chromosomes (they are now diploid) in order to create a human embryo.
Gametes are formed by a type of cell division called meiosis.
The gametes in:
The cells formed in meiosis are all genetically different. This is because the chromosomes - and genes - separate and are reshuffled during the process.
|Produces genetically identical daughter cells||Produces genetically varied daughter cells|
|Daughter cells have a full set of chromosomes (diploid)||Daughter cells have half a set of chromosomes (haploid)|
|2 daughter cells are produced||4 daughter cells are produced|
|Occurs in all body cells except gamete forming cells||Only occurs in gamete forming cells|