In osmosis, which description correctly explains the effect of a higher solute concentration on water movement?

In osmosis, which description correctly explains the effect of a higher solute concentration on water movement?

• A. Water moves toward compartments with lower solute concentration.
• B. Higher solute concentration pulls water into that compartment.
• C. Water movement occurs independently of solute concentration.
• D. Solutes move across membranes to balance concentrations rather than water.

Answer: (B)

Osmosis is water moving across a semipermeable membrane in response to solute differences, from an area of higher water potential to lower water potential. When one compartment has a higher solute concentration, it lowers the water potential there and creates a stronger osmotic pull. Water will move into that compartment to dilute the solutes and approach equilibrium. That’s why saying that higher solute concentration pulls water into that compartment best captures the process. The other descriptions don’t fit osmosis: water would not preferentially move toward the less concentrated side, and claiming movement is independent of solute concentration ignores the driving force of the osmotic gradient. Also, solutes moving to balance concentrations describes diffusion rather than the water-specific phenomenon of osmosis.

Osmosis is water moving across a semipermeable membrane in response to solute differences, from an area of higher water potential to lower water potential. When one compartment has a higher solute concentration, it lowers the water potential there and creates a stronger osmotic pull. Water will move into that compartment to dilute the solutes and approach equilibrium. That’s why saying that higher solute concentration pulls water into that compartment best captures the process.

The other descriptions don’t fit osmosis: water would not preferentially move toward the less concentrated side, and claiming movement is independent of solute concentration ignores the driving force of the osmotic gradient. Also, solutes moving to balance concentrations describes diffusion rather than the water-specific phenomenon of osmosis.