Question

Which is the process that enables the passage of water from the soil into the root hair?

Answer 1

The main concept for the movement of water from the soil to the xylem vessels is the difference in the osmotic pressure. There are water molecules present in the spaces between the soil particles. This water is available for the plants. The root hair cells have thin walls. The first interaction of water and the root hair cells is due to imbibition of water. This is the process of adsorption of water. The water then enters the cells of the root hair through osmosis. The osmotic pressure of water in the soil is more than the osmotic pressure in the root hair. The water is transported from the root hair to the other cells in the root region by osmosis. The movement of water from the root hair to the cortical cells and then to the layer of endodermis is through the process of osmosis down the concentration gradient. The water enters the cortex mostly by both apoplasts and then crosses endodermis through symplast to reach xylem vessels.