Question

for osmosis to occur, ____. pure water must be on one side of the membrane only solutes can pass through the membrane a concentration gradient cannot exist a selectively permeable membrane must be present cellular energy must be expended

Explanation:

Osmosis is the movement of solvent (usually water) across a selectively permeable membrane from an area of lower solute concentration to higher solute concentration. Key requirements include a selectively permeable membrane (allows solvent but not solute passage) and a concentration gradient. Pure water is not required, solutes cannot pass through the membrane, a concentration gradient must exist, and no cellular energy is needed (passive transport).

Answer:

a selectively permeable membrane must be present