How can surface area to volume ratio be decreased?
Cell growth causes the surface area to volume ratio to decrease. This is because, as a cell grows, the volume of the cell (its internal contents) increases faster than its surface area (its cell membrane). This is a problem for cells because the cell membrane has to have enough surface area for the transport of materials into and out of the cell. If the volume of the cell increases to the point that not enough materials can be transported into and out of the cell, it must either undergo mitotic cell division or no longer function. This is why cells are so small.