Question

How plants absorb water from the soil? Explain.

Answer 1

Hint: Soils can process and hold a considerable amount of water which is absorbed by the plants through various processes.

Complete answer:
-Plants absorb water from the soil with the help of roots. It also absorbs minerals in organic form through root hairs. The water and minerals get transported by xylem vessels.
-The carbon dioxide is taken from the atmosphere along with water and produces organic food. This food is transported through phloem and is called translocation.
-Osmosis plays a major role in the absorption of water and minerals by the root hair.
-When plants lose water in the form of water vapor, evaporation of water molecules creates a suction pull as transpiration causes a vacuum in the uppermost layer of the plant or aerial leaves.
-The intermediate cells lose water as a low concentration is created in the topmost layer. This process of osmosis continues and the suction pressure pulls the water in the xylem upwards creating a water column .
- Another pressure called root pressure is also important as it is exerted by the root due to its metabolic activities. It can move water through the xylem at night when transpiration is negligible and it can push the water in herbs till a certain distance/height.

Note: In smaller plants, through diffusion, the water moves from one cell to another while transpiration creates a pull(suction) to allow water to move through the xylem in bigger plants and trees.
Steel Rope means an unbroken and continuous water column.
The theory of absorption was given by Atkins (1916) and Preistley (1923)