Meiosis and Fertilisation

• Meiosis only takes place in reproductive organs (humans: testes and ovaries)
• In meiosis:

  • all chromosomes are copied
  • the cell now divides into 2
  • Now both of these cells divide 1 more time to form the gametes
  • chromosomes in the gametes are single not paired
• In fertilisation:

  • 1 male and 1 female gamete (not paired) join to form a cell with normal amount of chromosomes
• After fertilisation the new cell divides by mitosis, producing a clump of identical cells (embryo)
• As the embryo develops the cells differentiate forming different cell types. In animals this includes nerve and muscle cells