Question

How is water absorbed by root hairs in plants?

Answer 1

Root hairs:

1. Because root hairs have an expanded structure, there is more surface area available for water absorption.
2. Since root hair is hydrophilic and porous, it actively and passively takes water from the gaps between soil particles.

Active absorption:

1. Water is absorbed actively using adenosine triphosphate, which is the metabolic energy produced during respiration.
2. This form of absorption, which can be either osmotic or non-osmotic, occurs in low transpiring, well-watered plants.
3. Atkins and Priestley presented the active osmotic absorption idea in 1916 and 1923, respectively.
4. This hypothesis postulates that the root cells act as atypical osmotic pressure systems, where water is absorbed by the root's xylem in the presence of a concentration gradient.
5. Thiemann and Kramer presented the non-osmotic active absorption theory in 1951 and 1959, respectively.
6. They contend that the xylem found in the root absorbs water from the soil in opposition to the concentration gradient.

Passive absorption:

1. When there is no metabolic energy available, dirt is absorbed passively by roots.
2. Rapidly respiring plants experience it.
3. Transpiration leads to passive absorption (It is the process of movement of water in the plant, following its evaporation from aerial parts like a leaf, etc.).
4. As the xylem elements at the root receive the transpiration force, the root hair functions as an organ and the absorption process proceeds.