Produces two daughter nuclei that have the same number of chromosomes as the parent cell and each other.
Division of the nucleus of a cell that results in each of the daughter cells having an exact copy of the DNA of the parent cell.
Mitosis always preceeded by a period in which the cell is not dividing = Interphase.
Interphase is a period of considerable cellular activity including DNA replication.
1. Prophase = the chromosomes become visible and the nuclear envelope disappears
2. Metaphase = Chromosomes arrange themselves at the centre of the cell
3. Anaphase = Each chromatid migrates to opposite poles
4. Telophase = Nuclear envelope reforms
The importance of mitosis
Growth - when two haploid cells fuse together to form a diploid cell - has all the genetic information needed to form new organism. Cells must possess same genetic information if new organism is to resemble parents.
Differentiation - cells differentiate to give specialised cells. Each divide by mitosis to give tissues made of identical cells which perform a particular function. Essential because cell will only function if all its cells have the same structure and perform the same function.
Repair - important new cells have the identical structure and function as lost/dead ones - otherwise would not function effectively. Means by which new cells replace damaged / dead ones.