Which process moves water across a semipermeable membrane to equalize solute concentrations on both sides?

Which process moves water across a semipermeable membrane to equalize solute concentrations on both sides?

• A. Diffusion
• B. Active transport
• C. Osmosis
• D. Filtration

Answer: (C)

Osmosis is the movement of water across a semipermeable membrane from the side with lower solute concentration to the side with higher solute concentration. Because the membrane lets water through but not many solutes, water flows to balance solute levels and water potential on both sides, and the process doesn’t require energy. This distinguishes it from diffusion (which moves solutes), active transport (which uses energy to move substances against their gradient), and filtration (which is driven by pressure). The outcome is a more balanced distribution of solute concentrations across the membrane.

Osmosis is the movement of water across a semipermeable membrane from the side with lower solute concentration to the side with higher solute concentration. Because the membrane lets water through but not many solutes, water flows to balance solute levels and water potential on both sides, and the process doesn’t require energy. This distinguishes it from diffusion (which moves solutes), active transport (which uses energy to move substances against their gradient), and filtration (which is driven by pressure). The outcome is a more balanced distribution of solute concentrations across the membrane.