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

• Sexual reproduction is when a male gamete (sperm) and a female gamete (ova) combine to form offspring genetically different to the parents. 
• Gametes (sex cells) are sperm cells and egg cells produced by the testes and the ovaries respectively. They are produced by meiosis.
• Gametes are haploid, meaning that they only have 23 chromosomes. A full cell has 46 chromosomes. 
• In fertilisation, the gametes fuse to form a zygote which is a diploid cell of 46 chromosomes. (23 from each gamete). The zygote will inherit characteristics of both parents, therefore, it will not be genetically identical to the parent. It will result in genetic variation. 
• The zygote will undergo mitosis cell division and develop into an embryo.