Mitosis occurs in somatic, or body cells, while meiosis occurs in sex cells (eggs and sperm). Mitosis creates identical copies of cells, while meiosis creates cells with half the genetic material of the parent. If meiosis did not cut the chromosome number of the parent in half, the chromosome number would double each time fertilization occured.
Unlike meiosis, that can happen only in cells whose number of chromosomes is diploid or polypoid, mitosis can happen in both, haploid or diploid cells.
During the stages of process of mitosis specific cellular division , the cell is split in two, the result being two identical cells, called daughter cells.
These new daughter cells substitute the old, damaged cells, extending the life of the animals or plants.