Root pressure only provides a moderate push in the overall movement of water or water transport. It does not play a major role in the movement of water up the tall trees.
The main contribution of the root pressure is to re-establish the continuous flow of water molecules in the xylem which often break under the enormous tensions created by transpiration.
Apoplast pathway |
Symplast pathway |
1. Apoplast is the system of adjacent walls and continuous through the plant except at casparian strips. 2. There is no role of plasmodesmata. 3. It occurs through cell wall and intercellular spaces. Cell membrane is not crossed. 4. It is fast. 5. It is not aided by streaming movement of cytoplasm. 6. It does not involve osmosis. |
1. It is the system of interconnected protoplasts. 2. Continuity of protoplasm from one cell to another cell is through plasmodesmata. 3. It occurs through cell membrane. 4. It is slow. 5. It is aided by streaming movements of cytoplasm. 6. It involves osmosis. |
Imbibition |
Diffusion |
1. It is the proces by which solid absorbs water and swells up without getting dissolved. 2. In this only water or liquid is absorbed. 3. Imbibant is required. 4. Due to imbibition pressure is increased.
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1. It is the diffusion of molecules from higher concentration to lower concentration. 2. This may occur in water, liquids, solids and gases. 3. Imbibant is not required . 4. The pressure is reduced after diffusion.
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