• Surface area?and?volume?are both very important factors in the?exchange of materials?in organisms
• The surface area refers to the?total area of the organism that is exposed to the external environment
• The volume refers to the?total internal volume of the organism?(total amount of space inside the organism)
• As the surface area and volume of an organism increase (and therefore the overall ‘size’ of the organism increases), the surface area : volume ratio?decreases
• This is because?volume increases much more rapidly than surface area as size increases

As size increases, the surface area : volume ratio decreases

The surface area:volume ratio calculation differs for different shapes (these shapes can reflect different cells or organisms)