Question

Is there any difference between semi permeability and selectively permeability?

Answer 1

Definitions:

1. The semipermeable membranes permit the movement of solvent molecules through them but prevent the movement of solute particles.
2. The selectively permeable membrane is normally semipermeable but allows selective passage of solutes through them​.

Differences:

Semipermeable membrane	Selectively permeable membrane
1. It acts as a perfect partition between two osmotically active solutions or between a solution and its pure solvent.	1. It acts as an imperfect partition with the result that even plasmolyzed protoplasts get plasmolyzed automatically even kept in the same hypertonic solution.
2. It permits entry of only one solvent and solutes cannot pass through it.	2. It permits entry of both solvent and to a selected extent solutes.
3. This type of membrane is used in dialysis maintenance of turgidity and measurement of osmotic potential.	3. It is useful in maintaining turgidity while retaining the ability to absorb solutes.
4. Semi-permeable membranes are generally absent in biological system.	4. Biological system possess selectively permeable membrane.