In the context of cell processes, what does an increase in cell number due to division refer to?

An increase in cell number due to division is classified as cell proliferation. This process involves the multiplication of cells through the cell cycle, which encompasses stages such as interphase (where the cell grows and duplicates its DNA) and mitosis (where the actual division occurs). Proliferation is essential for growth, healing, and maintenance of tissues in multicellular organisms.

In this context, cell differentiation refers to the process by which cells become specialized for specific functions, rather than simply dividing. Cell growth indicates an increase in cell size rather than an increase in number. Lastly, cell aging involves the gradual deterioration of cell function and structure over time, which is different from the process of proliferation aimed at increasing cell number. Thus, the correct answer clearly identifies the specific process of cell division leading to an increase in cell numbers.