Explain the way how plants get water by osmosis through root hair.
- Root hair plays an important role in absorption of water by osmosis.
- Root hairs grow out into the spaces between the soil particles and that the hairs are surrounded by moisture.
- The soil water is more dilute than that of the cellsap in the root hair, therefore water will pass into the vacuole of the root hair by osmosis.
- The entry of water dilutes the contents of the root hair vacuole so that it becomes weaker than its neighbour.
- Therefore water passes into the neighbouring cell which in turn becomes diluted,
finally water enters the xylem vessels.
- As there are vast number of root hairs and root cells involved, a pressure in the xylem vessels develops which forces the water upwards.
- This total pressure is known as root pressure.
- Root pressure is not the main cause of movement of water in xylem but it is certainly one factor.