Question

Water will be absorbed by root hairs, when?

Answer 1

Hint: Root hairs also called as absorbent hairs are outgrowths of a trichoblast. It is a hair forming cell on the epidermis of a plant root. The lateral extends of a single cell are these structures and are rarely linked. They are found in the region of maturation. Also known as the zone of differentiation of the root. As we know, roots have a primary function to provide water which is obtained from soil and provide water to upper parts of plants. It also takes up nutrients from soil which helps in photosynthesis and other essential activities required for the growth of plants.

Complete answer:
As we knew about root hairs- water will be absorbed in the root hair when the concentration of solutes in the cell sap is high. The root cells are in contact with the ground, which actively absorbs ions and makes a difference between the root and soil concentration of these ions. Roots absorb active absorption of water. Active absorption refers to the absorption of water by roots with the help of adenosine triphosphate, generated by the root respiration.
As the root cells actively take part in the process hence it is termed as active absorption. Four percent total water is carried out in the process. The active absorption is carried out by two theories-active osmotic water absorption and active non-osmotic water absorption.
The root system is usually extensive and root hairs as we discussed absorb water as its surface helps in more water absorption. Water enters the root cells and then moves from cell to cell until it reaches the root cortex it goes on to xylem vessels to be transported to the leaves. Root hair contains cell sap of a higher concentration than that of surrounding soil water.

Note:
So, water absorption by root hairs occurs until the concentration of water in the cell sap is higher. As it distinguishes osmosis, water diffuses to the root hair. Root hair cells are adapted for taking up water and mineral ions by active transport, against the concentration gradient. Plants absorb water and mineral salt. They absorb it through osmosis.