Question

Explain the movement of water cell to cell across the root from the soil to the xylem.

Answer 1

The cell sap contains a more concentrated solute than the soil water around the root. Water enters into the root hair cells as long as DPD of cell sap is more. The cell wall gets distended, water first gets imbibed on the cell wall surface and then it comes in contact with the semipermeable cell membrane. After this, water is absorbed by either active or passive absorption.

From root hair water passes radially inward from cell to cell osmotically through cortex and endodermis and ultimately dropped into the xylem elements of root under pressure. From the root xylem, water moves upward in the vessels and tracheids of root and stem and is brought about by forces like root pressure, capillary force, the cohesion of water and the pumping activity of the living cortical cells.