The important point is that the surface area to the volume ratio gets smaller as the cell gets larger. Thus, if the cell grows beyond a certain limit, not enough material will be able to cross the membrane fast enough to accommodate the increased cellular volume. ... That is why cells are so small.

Why is a cell size small compared to big?

Cell size is limited by a cell's surface area to volume ratio. A smaller cell is more effective and transporting materials, including waste products, than a larger cell.

Why are cells generally of small size class 9?

The smaller the size of the cell large is the surface area to volume ratio. ... Thus, to make the process of transport easier and perform metabolic processes more efficiently, cells are generally small in size.