Question

Diffusion of water through selectively permeable membrane is:
A. Diffusion
B. Imbibition
C. Osmosis
D. Translocation

Answer 1

Hint: It is a process in which water molecules diffuse through a selectively permeable membrane from a region of high water concentration to a region of low water concentration.

Complete Answer:
- Osmosis is a type of simple diffusion. Osmosis may be defined as a process of spontaneous net movement of solvent molecules from a selectively permeable membrane into a region of high solute concentration.
- Osmosis is a vital process in biological systems. In the biological systems, the solvent is water. But osmosis can also occur in other liquids.
- The water molecules pass through the cell membrane from an area of low solute concentration to the area of high solute concentration, when the cell is submerged in water.
- Osmosis helps the plant roots to draw water from the soil. The plants concentrate solute in their roots by active transport. Thus, water enters the roots by osmosis.
- The movement of guard cells is controlled by osmosis.

So the correct answer is C Osmosis.

Note: If plant or animal cell is placed in solution of sugar or salt in water:
• Hypotonic – if the medium is hypotonic relative to cell cytoplasm, the cell will gain water through osmosis.
• Hypertonic – if the medium is hypertonic relative to cell cytoplasm, the cell will lose water by osmosis.
• Isotonic – if the medium is isotonic there will be no net movement of water.
• Selectively permeability is the property of cellular membranes to allow only certain molecules to enter or exit the cell.