Question

The surface area/volume ratio is an important factor for one-celled organisms. As a cell's volume grows, its surface area/volume ratio __________, making it ______________ to acquire enough nutrients via diffusion. A) increases; harder B) decreases; more difficult C) decreases; less difficult D) increases; use active transport

Answer 1

The correct answer is B) decreases; more difficult.

Unicellular organisms such as Amoeba, Paramecium depend on diffusion to move substances into and out of the cell. The surface area of unicellular organisms is large compared to its volume. Therefore, nutrients and other substances can easily cross the membrane and around their body.

As a cell's volume grows, its surface area/volume ratio decreases, making it more difficult to acquire enough nutrients via diffusion.