Answer:
C
Explanation:
Osmosis is the spontaneous movement or diffusion of water or other solvent molecules through a selective-permeable membrane from a solution containing low solute concentration (high solvent) to a solution containing high solute concentration (low solvent). Osmosis is a passive transport i.e it does not require energy, since the movement is down a concentration gradient.
Solutes cannot pass through the semi-permeable membrane, hence, they must be present in solutions. However, the driving force of the solvent shift is the concentration difference/gradient of solutes in the solutions separated by the semi-permeable membrane. The process of osmosis occurs until the concentration gradient of water or solvent becomes zero(0).
The tonicity (which is the ability of an extracellular solution to make water move in or out of a cell) of a solution can exist in three forms:
1. Hypertonic; when the solute concentration of a solution is greater than that of a cell. Thus, allowing water to flow out of the cell.
2. Hypotonic; when the solute concentration of a solution is lesser than that of a cell. Thus, allowing water to flow into the cell.
3. Isotonic; when the solute concentration of a solution is equal to that of a cell. This causes osmosis to stop or not occur, as the concentration gradient is said to be 0.
