Transport system in Plants

How the xylem vessel carries water

ROOT PRESSURE

Water that is present in the soil, is absorbed by osmosis into the root hairs of plants.

The water then travels through the cortex of the root, from cell to cell.

A root pressure is therefore created, and this forces water from the cortex into the xylem vessel

CAPILLARITY

Through capillarity, water moves up the xylem in a continuous stream. The water molecules are attracted to the walls of the vessels (adhesion) and they are also attracted to each other (cohesion). This cause an upward movement of water in the xylem, against gravity

TRANSPIRATION PULL

Transpiration occurs in leaves of plants. This loss of water causes a vacuum to be created in the xylem. There is therefore a high water pressure at the bottom, and a lower water pressure at the top of the xylem. Therefore, there is an upward pull of water.