AP BIOLOGY

Detailed explanation-1: -If a cell grows larger, then the volume increases much more rapidly than the surface area, causing the ratio of surface area to volume to decrease. The problem is that the cell would not be able to get enough oxygen and nutrients in and get the waste products out.

Detailed explanation-2: -When the cell increases in size, the volume increases faster than the surface area, because the volume is cubed where surface area is squared. For a single-celled organism (or a cell in a multicellular organism’s body, for that matter), the surface is a critical interface between the organism.

Detailed explanation-3: -As a cell grows bigger, the internal volume increases and thereby expands the cell membrane. In turn, the volume increases more rapidly than does the surface area. Thus, the relative amount of surface area available to pass materials to a unit volume of the cell decreases.

Detailed explanation-4: -Graphs of surface area, A against volume, V of the Platonic solids and a sphere, showing that the surface area decreases for rounder shapes, and the surface-area-to-volume ratio decreases with increasing volume.