Question

water column is maintained inside xylem vessels give reasons

Answer 1

Answer: Water column in xylem vessels are constantly maintained due to cohesion and transportation pull theory.

As the xylem vessels are connected to each other, it allows water to stay in a continuous column to the mesophyll cells from the root hairs.

Lignin and cellulose of xylem have strongly adhered water.

Answer 2

The theory which is shown here is the transpiration pull theory and ascend of the sap. According to the theory when there is transpiration occouring in the plant leaf there is ascend of sap. It is because there is a pull which is created in the water column which is in the xylem cells and then due to this and cohesion theory there is a constant water column which is set up in the xylem vessel and thus the ascent of sap is explained.