What is the purpose of mitosis and explain the stages

Mitosis is used for growth, repair and replacement of tissue or in the case of asexual organisms - reproduction. It results in the formation of daughter cells which are genetically identical to the original cell, in terms of the genetic content and also in terms of the number of chromosomes. There are 4 phases of mitosis - prophase, metaphase, anaphase and telophase. Prophase involves the DNA becoming visible due to the chromatin undergoing shortening and thickening (supercoiling), at this period of time each chromosome has 2 molecules of DNA as a result of replication. By the end of prophase - the chromosomes have become visible, nucleolus has disappeared and the nuclear membrane has broken down.Metaphase occurs occurs when the centrosomes move to the poles of the cell and begin to form the spindle, which forms the frame which drags the chromatids to the opposite poles. The centrosome of each chromosome attaches to the spindle at the centre (equator of the cell).Anaphase occurs when the centromeres divide and the separated chromatids are pulled by the centromeres to the poles of the cell which leads to the chromatids splitting into 2.During telophase - there is now double the genetic material in a single cell. So nuclear membranes are formed around each group of chromosomes, which being to uncoil forming the genetic material chromatin.