1. Cell divide for many reasons. For instance: when a person skins their knee, cells divide to replace old, dead or damaged cells. Cells also divide so living things grow, organism grow because cells are divided to produce more and more cells.
2. The important point is that the surface area to the volume ratio gets smaller as the cell gets larger. When this happens, the cell must divide into smaller cells with favorable surface area and volume ratios or cease to function. This is why cells are so small.
