Posted in Biology


Cell division is an important function for example growth and repair. We call this process mitosis.

You need to know what happens during this process including how the amount of DNA changes.

You should already know that the human cells contain 23 pairs of chromosomes, 23 from mum and 23 from dad. New cells that are created by mitosis should be genetically identical (clones). This will not be the case when you look at making sperm and egg cells (ovum).


  1. The cell needs to grow and copy all of its DNA
  2. The chromosomes line up in the centre of the cell
  3. Special fibres pull the chromosomes to opposite ends of the cell
  4. The cell starts to pinch in the centre as it starts to split 
  5. The cell divides and we now have 2 genetically identicaldaughter” cells


n – Is the normal amount of DNA found in the cell

2n – Is twice as much DNA as normal