Memory Anchor:

• Super Challenge:

  Stretch:

  Challenge:

Key Questions:

1. What happens to the number of chromosomes in gametes from meiosis? How is the full number of chromosomes restored?
   • Meiosis halves the number of chromosomes. The full number is restored during fertilisation.
2. How are gametes formed?
   • Cells in reproductive organs divide by meiosis to form gametes.
3. What happens when a cell divides to form gametes? Are the gametes genetically identical or different?
   • First copies of the genetic information are made. Then the Cell divides twice to form four gametes each with a single set of chromosomes. All gametes are genetically different from each other.
4. What happens during fertilisation? What happens to the cells as the embryo grows?
   • The gametes join and this restores the number of chromosomes. The new Cell then divdes by mitosis and the number of Cells increases. As the embryo develops Cells differentiate.