Important definitions

Contains all important definitions

Imbibition

Imbibition is the phenomenon by which living or dead plant cells absorb water by surface attraction.

Diffusion

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

Osmosis

Osmosis is the movement of water molecules from their region of higher to lower concentration through a semi-permeable membrane.

Osmotic pressure

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

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.

Turgidity

It is the state of a cell in which the cell wall is rigid and stretched by an increase in the volume of vacuoles due to absorption of water.

Plasmolysis

It is the contraction of cytoplasm from the cell wall caused due to the withdrawal of water when placed in a strong (hypertonic) solution.

Flaccidity

It is the condition in which the cell content is shrunken and the cell is no more “tight”.

Root pressure

Root pressure is the pressure developed in roots due to continued inward movement of water through cell-to-cell osmosis which helps in the ascent of cell sap upward through the stem.

Tonicity

Tonicity is the relative concentration of the solutions that determines the direction and extent of diffusion.