NEET BIOLOGY

Detailed explanation-1: -As the radius of a cell increases, its surface area increases as the square of its radius, but its volume increases as the cube of its radius (much more rapidly). Therefore, as a cell increases in size, its surface area-to-volume ratio decreases.

Detailed explanation-2: -As cells grow larger, the ratio of surface area to volume decreases dramatically, just like in your agar cubes. Larger cells must still transport materials across their membranes, but have a larger volume to supply and a proportionately smaller surface area through which to do so.

Detailed explanation-3: -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.

Detailed explanation-4: -(a) Cell rounding requires a decrease in the cell surface area-to-volume ratio.

Detailed explanation-5: -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.