Question

which of the following models demonstrates simple diffusion through a selectively permeable membrane? image of model a (particles moving through lipid bilayer) and model b (particles moving through a transport protein) options: a) model a because particles are moving directly through the cell membrane with the use of atp. b) model b because particles are moving through a transport protein without the use of atp. c) model a because particles are moving directly through the cell membrane from high to low concentration. d) model b because particles are moving through a transport protein from high to low concentration.

Explanation:

To determine which model represents simple diffusion, we analyze each option:

• Option A: Mentions using ATP, but simple diffusion doesn't require ATP. Eliminate A.
• Option B: Mentions a transport protein and no ATP, but simple diffusion doesn't use transport proteins. Eliminate B.
• Option C: States particles move directly through the cell membrane from high to low concentration. Simple diffusion is the passive movement of particles down their concentration gradient (high to low) directly through the lipid bilayer, no ATP or transport proteins needed. This matches.
• Option D: Mentions a transport protein, but simple diffusion doesn't use them. Eliminate D.

Answer:

C. Model A because particles are moving directly through the cell membrane from high to low concentration.