Mitosis, a need to know...
Mitosis, as the textbook would say, refers to the process of nuclear division where two genetically identical nuclei are formed from one parent cell nucleus. To help describe what is going on as one nucleus devides into two, Biologists split the sequence into four distinct, named phases.
1) Prophase -
In prophase, the chromosomes supercoil (shorten and thicken). The Nuclear envelope, which is the membrane that surrounds the nucleus holding it together, breaks down and disappears. An organelle called a centriole divides in two and each daughter centriole moves to opposite ends of the cell to form the spindle. This structure looks sort of like a globe with lines of latitude drawn on it.
2) Metaphase -
The chromosomes line up down on the equator (middle) of the cell. When the chromosomes are in the centre of the cell, they attach themselves to the spindle, ready for anaphase.
3) Anaphase -