DIFFUSION=It is the spontaneous movement of particles of a substance in a gas or liquid form from a region of its higher concentration to a region of its lower concentration.

FUNCTIONS

*It helps in exchange of respiratory gases.
*it helps in the distribution and spread of different substances in the cytoplasm.

OSMOSIS= the movement of water molecules through a selectively permeable membrane(plasma membrane) from a region of higher water concentration to a region of lower water concentration.

FUNCTIONS

* roots absorb water from soil by osmosis.
* cell to cell movement of water absorbed by roots also takes place by osmosis.

Diffusion:
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. It occurs in both liquids and gases, as well as across cell membranes. Diffusion does not require any energy input and is driven by the random motion of molecules.

Key Points:
- Movement of molecules from high to low concentration
- Occurs in liquids, gases, and across cell membranes
- No energy input required
- Driven by random motion of molecules

Osmosis:
Osmosis is a specific type of diffusion that involves the movement of water molecules across a semipermeable membrane. A semipermeable membrane allows the passage of water molecules but restricts the movement of solute particles. Osmosis occurs when there is a difference in solute concentration between two solutions separated by a semipermeable membrane.

Key Points:
- Movement of water molecules across a semipermeable membrane
- Involves a difference in solute concentration
- Semipermeable membrane allows water passage but restricts solute movement

Differences:
1. Movement of Molecules:
- Diffusion: In diffusion, molecules move from an area of higher concentration to an area of lower concentration, regardless of the type of molecule.
- Osmosis: Osmosis specifically involves the movement of water molecules across a semipermeable membrane.

2. Types of Membrane:
- Diffusion: Diffusion can occur in any type of membrane, including semipermeable membranes.
- Osmosis: Osmosis occurs across a semipermeable membrane, which allows the passage of water but restricts solute movement.

3. Concentration Gradient:
- Diffusion: The driving force behind diffusion is the concentration gradient, i.e., the difference in concentration between two regions.
- Osmosis: Osmosis occurs when there is a difference in solute concentration between two solutions separated by a semipermeable membrane.

4. Energy Requirement:
- Diffusion: Diffusion is a passive process and does not require any energy input.
- Osmosis: Osmosis is also a passive process and does not require energy.

5. Examples:
- Diffusion: Examples of diffusion include the spreading of perfume in a room, the mixing of gases in the atmosphere, or the movement of molecules across a cell membrane.
- Osmosis: Examples of osmosis include the absorption of water by plant roots, the rehydration of dried fruits when placed in water, or the movement of water across red blood cells.

In conclusion, diffusion and osmosis are both passive processes involving the movement of molecules. Diffusion refers to the movement of molecules from an area of higher concentration to an area of lower concentration, while osmosis specifically involves the movement of water molecules across a semipermeable membrane in response to a difference in solute concentration.