Through the process of _______, materials move across a cell membrane from an area of higher concentration to an area of lower concentration.
A.
diffusion
B.
photosynthesis
C.
friction
D.
cellular respiration
The answer is A.
Remember that diffusion is the spontaneous process of solutes moving from areas of higher concentration to areas of lower concentration (spontaneous just means the process doesn't require an input of energy to occur).
