Question

As a cell grows, what happens to its surface area: volume ratio?

a) Decreases
b) Increases
c) Remains constant
d) Fluctuates randomly

Answer 1

As a cell grows, its surface area-to-volume ratio decreases because surface area increases by the square of the radius while volume increases by the cube of the radius, making large cells inefficient.

Step-by-step explanation:

As a cell increases in size, what happens to its surface area-to-volume ratio? The correct answer is a) Decreases. This happens because the surface area increases by the square of the radius, while the volume increases by the cube of the radius. For example, a cell that grows from a volume of 1 mm³ with a surface area of 6 mm², to a volume of 8 mm³ with a surface area of 24 mm², will see its surface area-to-volume ratio decrease from 6:1 to 3:1. If a cell grows too large, it becomes inefficient due to insufficient surface area to support the needs of the increased volume, particularly in regards to the rate of diffusion required.