Mitosis is important in growth, repair and asexual reproduction. Mitosis is the process where the nucleus of a cell divides into two daughter nuclei.The two daughter nuclei are genetically identical to each other and the parent nucleus that gave rise to them.There are four stages of mitosis:Prophase: The nuclear envelope breaks down and the nucleolus disappears. Chromosomes shorten and thicken and become visible. Each chromosome consists of two identical chromatids held together at the centromere.The centrioles move to opposite poles of the cell and spindle fibres grow from each centriole towards the middle of the cell. Plant cells develop spindles but do not have centrioles. The chromosomes start to move towards the middle of the cell.Metaphase: By metaphase, chromosomes have reached the metaphase plate (or equator) in the middle of the cell. They are attached to the spindles by their centromeres. The spindles are microtubules that are responsible for the movement of the chromosomes to the equator. The energy for this movement is provided by mitochondria and is in the form of the energy yielding bonds of ATP.Anaphase: The centromeres split into two as the spindle fibres attached to the centromeres shorten. This pulls the two chromatids apart and they move towards each pole centromere first. Each chromatid is now a chromosome.Telophase: Once the chromosome reaches the pole they unwind and become loosely coil chromatin. The spindle fibres disintegrate and the nuclear envelope and nucleolus reform.