Which of the following procedures would best demonstrate cellular osmosis? a. a procedure that uses the skins of potato left overnight in oil b. a procedure that uses a banana that has been left overnight in milk c. a procedure that uses grapes left overnight in a high concentration of salt water d. a procedure that uses a 2-liter bottle filled with oil and water that is left overnight

The correct answer is: C. a procedure that uses grapes left overnight in a high concentration of salt water

Osmosis is the passive process (no energy required) of solvent molecules movement through a selectively permeable membrane. The process is passive because the solvent (water) moves from the region of low solute concentration into a region of high solute concentration. This happens in order to equalize the solute concentrations on the two sides.  

In the case of grapes, water will move from the grapes into the high salt surrounding water.