Biology
Draw a magnified view of the root-hair, and describe how it helps in the absorption of water from the soil?
Answer
Given below is the magnified view of a root-hair. It is a long protuberance of an epidermal cell of the root. This cell contains a fluid sap which is more concentrated than the surrounding soil water. It has a outer cell wall and an inner cell membrane. Cell wall is freely permeable whereas cell membrane is semi-permeable. The cell membrane allows the water molecules to pass through it but prevents the other larger molecules. So, the water from the soil passes into the root hairs by Osmosis.
Related Questions
The set up shown alongside was kept in sunlight for an hour. It was observed that drops of water appeared on the inside surface of the polythene bag.
(a) Name the process which is being demonstrated.
(b) Why was the pot with its soil left uncovered by the polythene bag?
(c) Why was the pot left in sunlight?
(d) Suppose that the pot in this experiment was placed inside a dark room instead of placing it in sunlight for some time. What difference would be noticed?
Briefly explain, how transpiration helps in the upward conduction of water in plants?
How does temperature, light intensity and wind affect transpiration?
Draw a magnified view of the root hair and label all its parts neatly. From the parts labelled by you, name the parts matching the description given below:
(a) Outermost layer of the root
(b) Unicellular outgrowth
(c) Part that is freely permeable
(d) Part that is semi-permeable