Final answer:
The solvent in osmosis in living systems is water, which moves across a semipermeable membrane from an area of high water concentration to an area of low water concentration, facilitated by aquaporins, until equilibrium is reached.
Step-by-step explanation:
The solvent in osmosis in living systems is water. Osmosis is the movement of water across a semipermeable membrane from an area of higher water concentration to an area of lower water concentration. This process occurs due to the presence of solute concentrations that cannot cross the membrane, creating a gradient that drives the movement of water.
The goal is to achieve equilibrium in solute and water concentrations on both sides of the membrane. A critical component in this process is aquaporins, which are proteins that facilitate the movement of water across cell membranes. Water moves in response to a concentration gradient, which means it moves toward the area where the concentration of solutes is higher, since this is where the concentration of water is relatively lower.
This movement continues until the concentration gradient of water goes to zero or until the hydrostatic pressure of the water balances the osmotic pressure, at which point equilibrium is reached.