Biology
Answer
(a) Semi-permeable membrane — A semi-permeable membrane is a membrane which allows the passage of molecules selectively. It allows a solvent such as water molecules to pass through it freely but prevents the passage of the solute (sugar or salt molecules in solution).
(b) Osmosis — Osmosis is the movement of water molecules from their region of higher concentration (dilute solution or with a lower solute concentration) to their region of lower concentration (concentrated solution or with a higher solute concentration) through a semi permeable membrane.
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