Question

question 17
what characteristic is shared by diffusion and facilitated diffusion?
a both require a special carrier molecule to move substances across the membrane
b both involve movement from higher particle concentration to lower particle concentration
c both involve the movement of water across a semipermeable membrane
d both require cellular energy for the transport of substances from low concentrations to high concentrations

Explanation:

• Option A: Only facilitated diffusion requires a carrier molecule; simple diffusion does not.
• Option B: Both diffusion and facilitated diffusion are passive transport processes. Passive transport moves substances down their concentration gradient (from higher to lower particle concentration).
• Option C: Movement of water across a semi - permeable membrane is specifically called osmosis (a type of diffusion for water). But the general diffusion can involve other substances too, not just water.
• Option D: Both diffusion and facilitated diffusion are passive and do not require cellular energy (ATP). Active transport is the one that requires energy to move substances against the concentration gradient.

Answer:

B. Both involve movement from higher particle concentration to lower particle concentration