Which cell types remain in a non-dividing stage and do not complete the mitosis process?

Answer;

Muscle cells and nerve cells

Explanation;Mitosis is a type of cell division which occurs in the somatic cells or the body cells where cells divides to generate daughter cells that are identical to the parent cells.All the body cells undergo mitosis a process that enhances growth, however, the muscle cells and the nerve cells are specialized cells that remain in a non-dividing stage and do not complete the process of mitosis. Nerve cells for example they can never be created again once they die.These cells, nerve cells and muscle cells lack repair mechanisms for injuries. Since they are specialized cells they loose the ability to divide by mitosis.

That would be a working theory.