The process of cell division whereby the chromosomes are duplicated and distributed equally to the daughter cells is called mitosis.
1) Growth of the organism
An adult human being is made up of billions of cells and all cells have the same genetic component. This genetic stability is achieved by mitosis. All these cells are formed from the first cell zygote by mitosis. Zygote divides by mitosis to form genetically identical daughter cells.
In the case of wound healing; that should be replaced with the same type of cells with the same genetic quality. This is achieved by mitosis.
Take blood cells as example. RBC has a life span of 120 days. After that it should be replaced by new cells. This is achieved by mitosis. Similarly skin cells are replaced continuously
4) In plants, vegetative multiplication is by mitosis (asexual reproduction)