Define the following terms:

(a) Imbibition

(b) Diffusion

(c) Osmosis

(d) Osmotic pressure

(e) Active transport

(f) Tonicity

(g) Root pressure

(a) Imbibition — Imbibition is a phenomenon by which the living or dead plant cells absorb water by surface attraction. Its the passive absorption of water by substances such as cellulose (in cell wall) and starch.

(b) Diffusion — Diffusion is the free movement of molecules of a substance (solute or solvent, gas, liquid) from the region of their higher concentration to the region of their lower concentration when the two are in a direct contact.

(c) Osmosis — Osmosis is the movement of water molecules from their region of higher concentration (dilute solution or with a lower solute concentration) to their region of lower concentration (concentrated solution or with a higher solute concentration) through a semi permeable membrane.

(d) Osmotic pressure — Osmotic pressure is the minimum pressure that must be exerted to prevent the passage of the pure solvent into the solution when the two are separated by a semi-permeable membrane.

(e) Active transport — Active transport is the passage of a substance from its lower to higher concentration through a living cell membrane using energy from the cell.

(f) Tonicity — Relative concentration of the solutions that determine the direction and extent of diffusion is called tonicity.

(g) Root pressure — The upward flow of water due to heavy pressure from the roots is called root pressure. Thus, it is one of the forces to raise water up through the stem into the leaves.