b) Osmosis

Passive Transport Mechanism :

b) Osmosis :

Osmosis is defined as the net movement of the solvent molecules across the selectively permeable membrane from an area in which the solvents molecules are highly concentrated to an area of low concentration until it reach to the equilibrium.

Osmosis is the movement of a solvent across a semipermeable membrane toward a higher concentration of solute (lower concentration of solvent). In biological systems, the solvent is typically water, but osmosis can occur in other liquids, supercritical liquids, and even gases

Above is the figure which shows selectively permeable membrane  transport mechanism of living cell image cortessy : wikipedia

The figure showing chief solvent #Water in the living system these are categaries as they are normally found in
1.Hypertonic
2.Isotonic
3.Hypotonic

Hypertonic solution : A solution that contains more dissolved particles (such as salt and other electrolytes) than is found in normal cells and blood.

An isotonic solution is one that has the same osmolarity, or solute concentration, as another solution. If these two solutions are separated by a semipermeable membrane, water will flow in equal parts out of each solution and into the other.

A hypotonic solution has a lower concentration of solutes than another solution.  Means, a solution outside of a cell is called hypotonic if it has a lower concentration of solutes relative to the cytosol. Due to osmotic pressure, water diffuses into the cell, and the cell often appears turgid, or bloated.