Final answer:
The statement is false because osmosis requires a difference in solute concentration, not necessarily large differences in water concentration, to drive the movement of water across a membrane.
Step-by-step explanation:
The statement 'Large differences in water concentration are required to drive water across a membrane' is false. Osmosis, the movement of water across a semipermeable membrane, is driven by the desire to equalize solute concentrations on both sides of the membrane. It does not require large differences in water concentration; rather, it requires a difference in solute concentration. When a semipermeable membrane separates two solutions with different concentrations of solutes, the water will naturally move from the side with the higher water concentration (lower solute concentration) to the side with the lower water concentration (higher solute concentration). This process is facilitated by aquaporins, which are specialized channels that allow water molecules to pass through the membrane more efficiently.