1. Growth and Development: Mitosis is essential for the growth and development of multicellular organisms. It allows for the production of new cells to increase the size of an organism and to form tissues and organs.

2. Repair and Regeneration: Mitosis is crucial for the repair of damaged tissues and organs. For example, when you get a cut, mitosis creates new cells to replace the damaged ones. It also allows for the regeneration of lost tissues, such as after a burn or wound.

3. Asexual Reproduction: In some organisms, mitosis is the primary mechanism for asexual reproduction. This means that a single parent cell divides to produce two identical daughter cells, which can then develop into new individuals. This is common in single-celled organisms and some plants.