meiosis

• Meiosis

  The process by which gametes (sperm and egg cells) are produced, with half the normal number of chromosomes
• Chromosomes in normal human cells

  • 23 pairs
• Chromosomes in gametes

  • Single, not paired
• Meiosis

  1. Chromosomes are copied

  2. Cell divides into two

  3. Both cells divide one more time forming gametes
• Meiosis produces four gametes from one original cell, and each gamete is genetically different
• Fertilization


  The joining of a male gamete (sperm) and a female gamete (egg) to form a new cell with the full number of chromosomes
• Meiosis


  Halves the number of chromosomes
• Fertilization

  Restores the full number of chromosomes
• Embryo


  The clump of identical cells that forms after fertilization, which then differentiates into different cell types
• You'll find plenty of questions on meiosis and fertilization in the revision workbook