What is osmosis?

Osmosis is defined as the movement of water molecules across a selectively permeable membrane. This process occurs when there is a difference in the concentration of solutes on either side of the membrane, leading water to move towards the area of higher solute concentration to achieve equilibrium. The selectively permeable nature of the membrane allows water to pass through while preventing certain solute particles from crossing, which is a key aspect of osmosis.

Understanding osmosis is crucial in biological contexts, as it plays a vital role in maintaining cell turgor pressure, regulating fluid balance in biological systems, and facilitating nutrient absorption in both plant and animal cells. This fundamental process not only affects how cells interact with their environment but also how they maintain homeostasis.

Other options, while related to different biological or physical processes, do not accurately describe osmosis. Active transport involves the energy-dependent movement of ions or molecules against a concentration gradient, photosynthesis involves the conversion of light energy into chemical energy in plants, and gas diffusion deals with the spread of gas particles in the atmosphere, which are distinct from the water movement described in osmosis.