Vividly demonstrate selective permeability using colored solutions

Starting with a model cell and a mixture of special dye solutions, your students will observe how the cell's membrane allows one dye to pass, while the other remains within the cell. The resulting color change provides a vivid demonstration of selective permeability and how the cell absorbs nutrients an discharges wastes. The class will also learn how osmosis and diffusion permit the maintenence of equilibrium through the passive transport of water through the cell's semipermeable membrane.