Question

Which of the following is true about facilitated diffusion?

a) Particles are usually too large (or have another characteristic) to pass directly through the cell membrane.
b) It is a passive process.
c) Particles have a net movement from low concentration to high concentration.
d) The particles use protein channels to pass through the cell membrane.

Answer 1

Facilitated diffusion is a passive process where particles move down their concentration gradient through specific protein channels in the cell membrane.The correct options are b) and d).

Step-by-step explanation:

Facilitated diffusion is a passive process, meaning it does not require energy. Option b) is correct. In facilitated diffusion, particles move down their concentration gradient through specific protein channels in the cell membrane.

These protein channels help large or charged particles that cannot pass freely through the lipid bilayer of the membrane. Therefore, option d) is also correct. Particles are usually too large or have another characteristic that prevents them from passing directly through the cell membrane.

Option a) is incorrect because facilitated diffusion allows particles that cannot freely pass through the membrane to cross with the help of protein channels. Option c) is also incorrect because facilitated diffusion occurs from an area of higher concentration to an area of lower concentration, following the concentration gradient.