Question

which process moves materials against a concentration gradient?
dialysis
osmosis
active transport
simple diffusion
facilitated diffusion

Explanation:

Dialysis, osmosis, simple diffusion, and facilitated diffusion are passive processes that move substances down their concentration gradient (from high to low concentration) without energy. Active transport requires energy (e.g., ATP) to move materials against the concentration gradient (from low to high concentration).

Answer:

active transport