B13.2

• What is meiosis?


  Meiosis is a type of cell division that produces gametes (sex cells).
• How many times do cells divide in meiosis?

  They undergo 2 rounds of nucleur division.
• How many cells are produces in meiosis?

  Meiosis produces 4 genetically unique haploid daughter cells that will go on to develop into gametes.
• Where are male/female gametes made?

  Male - Testes

  Female - Ovaries
• Are the cells produced by meiosis genetically identical to each other, or genetically unique?

  Genetically unique
• Process of meiosis

  1. Replicate DNA

  2. Chromatids line up in the centre in their pairs randomly

  3. First Division - Meiotic Spindles pull chromosomes apart

  4. Second Division - Chromosomes line up along centre of the cell, Meiotic spindles pull apart the arms of the chromosomes to opposite poles of the cell, Cell divides again producing 4 cells
• How does sexual reproduction introduce variation?

  Gametes are required and are all different.

  When gametes fuse, one pair of each chromosomes from each parent is needed.

  Combination of genes in new pair of chromosomes will form alleles from each parent.