Sexual Reproduction, Meiosis & Fertilisation

SEXUAL REPRODUCTION: - Gametes in: animals - sperm and eggs; flowering plants - pollen & eggs - Offspring in sexual reproduction are genetically different to each other and the parents, resulting in variation as genetic info mixes MEIOSIS: Sexual reproduction uses the process of meiosis, which creates gametes, it happens in the male and female reproductive organs. As a cell divides to form gametes: - copies of the genetic information is made - the cell divides twice to form four gametes, each with a single set of chromosomes (haploid) - all gametes are genetically different from each other FERTILISATION: - The fusion of the nucleus of a male gamete with the nucleus of a female gamete - 23 chromosomes in a gamete - a haploid. When 2 gametes combine, they merge the 2 sets of chromosomes to have 46 - a diploid - This produces a new cell called a zygote, which matures into an embryo, the no. of cells increase by mitosis & the cells begin to differentiate as the embryo develops