Why are cells microscopic due to volume ratios?

Answer 1

The smaller a cell is, the greater the ration of Surface Area to Volume.

As the cell size increases, the ratio of surface area to volume decreases. Volume will increase rapidly while surface area increases slowly.

Cells must maintain a balance between surface area and volume because the amount of surface area determines how much food it can take in and how much waste it can remove. The greater the surface area, the longer it can survive.

Answer 2

Consider a cube measuring 1'x1'x1'. it has a surface are of 6 and a volume of 1 giving it a ration of 1:6. Now imagine doubling all those measurements making a cube 2'x2'x2'. This cube would have a surface area of 30 and a volume of 8 giving this larger cube a ratio of 1:3.75. As the cube gets bigger the volume increases faster then the surface are does. This same concept can be applied to cells which need a large surface area compared to their volume so that molecules and nutrients can be effectively diffused to all parts of the cell from outside.