-Gametes are sex cells.
-At fertilisation sperm and egg join together to form a zygotes.
-Normal body cells have the diploid number of chromosomes, whereas gametes have a haploid number of chromosomes.
-Fertilisation is random, so is the combination of zygotes, resulting in genetic diversity within a species.
-Gametes are formed by meiosis.
-Before meiosis stars, the DNA unravels and replicates into two copies of chromosomes.
-Meiosis has two main stags:
-> Prophase I : - Duplicated chromosomes condense and thicken.