Question

Why and how does water enter continuously into the root xylem?

Answer 1

There is a high tension and low pressure created in the root hair epidermis. This is because of the transpiration pull exerted by loss of waterby transpiration. This low pressure favors osmotic uptake of water and minerals from the soil into the root.

Answer 2

Answer:

Xylem transports water and minerals to the plant body. The roots of a plant have hair called root hairs. The root hairs are directly in contact with the film of water in between the soil particles. Water and minerals get into the root hair by the process of diffusion. The water and minerals absorbed by the root hair form the soil pass from cell to cell by osmosis through the epidermis root cortex, endodermis and reaches the root xylem. The xylem vessels of the root the plant are connected to the xylem vessels into stem.

Therefore, the water containing dissolved minerals enter the root xylem vessels into stem xylem vessels. The xylem vessels of the stem branch into the leaves of the plants. So the water & minerals carried by the xylem vessels in the stem reach the leaves through the branched xylem vessels which enter from the petiole into the each part of the leaf. Thus the water and minerals form the soil reach through the root and stem to the leaves of the plants.

Evaporation of water molecules from the cells of a leaf creates a suction which pulls water form the xylem cells of roots. The loss of water in the form of vapour from the aerial parts of the plants is known as transpiration.