Answer:
The cell process that causes grow and repair of body cells including skin and nails is called mitosis.
The process of mitosis increases number of cells and enable them grow and also replaces the dead cells or lost cells with new cells for proper functioning of cells. Mitosis is important for the replacement of cells which constantly lost and grow.
In the mitosis process, parent cell split into twin daughter cell and carry identical DNA which helps in replacement of lost cells and growth of cell as in skin and nails.
Hence, mitosis helps in the renewal and growth of skin cells and nails.