The absorption of nutrients by simple diffusion requires:

Question

Quizplus · Accepted Answer

Simple diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration, down a concentration gradient. Therefore, the absorption of nutrients by simple diffusion requires a concentration gradient. Choice A is incorrect because carrier molecules are used in facilitated diffusion, not simple diffusion. Choice B is incorrect because simple diffusion does not require energy. Choice D is incorrect because only a concentration gradient is required for simple diffusion.

The Absorption of Nutrients by Simple Diffusion Requires