Final answer:
Osmosis is the movement of water across a semi-permeable membrane from a low to a high solute concentration, aiming for equilibrium. The answer to the fill-in-the-blank question is A. semi-permeable, low, high.
Step-by-step explanation:
Osmosis is the net movement of water molecules across a semi-permeable membrane from a region of low solute concentration to a region of high solute concentration (until equilibrium is reached). The correct answer to the question is: A. semi-permeable, low, high. In physiological processes, osmosis facilitates the transport of water to maintain cellular integrity and adapt to changes in solute composition in the extracellular environment. Semi-permeable membranes are key to this selective movement, permitting the passage of water but restricting larger molecules like glucose or proteins, thus maintaining an optimal balance for normal cell function.