[Campbell Biology P.182] Which of the following statements accurately describes the process ... | Practice Question
Which of the following statements accurately describes the process of diffusion as explained in the text?
A: Diffusion is an active transport process that requires direct input of cellular energy.
B: Each substance diffuses down the total concentration gradient of all solutes combined.
C: Once dynamic equilibrium is reached, solute molecules stop moving across the membrane.
D: Diffusion is a spontaneous process where substances move from an area of higher concentration to an area of lower concentration.
Explanation
The text defines diffusion as a 'spontaneous process' where a substance 'diffuses down its concentration gradient,' moving from a more concentrated area to a less concentrated area without needing energy input.