3.2 understand that fertilisation involves the fusion of a male and female gamete to produce a zygote that undergoes cell division and developed into an embryo

When fertilisation occurs, a male gamete fuses with a female gamete to form a zygote (aka a fertilised egg). This zygote will then undergo cell division by mitosis (reproducing genetically identical cells), this develops into an embryo (effectively a ball of cells).

The embryo contains chromosomes from mum and dad and therefore receives characteristics from both parents. The process of fertilisation is random resulting in genetic variation.

NOTE: Gametes are haploid cells meaning they contain half the number of chromosomes (23) instead of the full 46 like in every other cell. This means that the zygote ends up with a full set of chromosomes (46) as the male gamete (of 23 chromosomes) will fuse with the female gamete (of 23 chromosomes) when fertilisation occurs.