Osmosis is a process by which the molecules of a solvent pass from a solution of low concentration to a solution of high concentration through a semi-permeable membrane. It is a form of passive transport that happens without any expenditure of energy. In biology, osmosis is the movement of water molecules from a solution with a high concentration of water molecules to a solution with a lower concentration of water molecules through a semi-permeable membrane.

Osmosis is a crucial process in living organisms. For example, absorption of water through plant roots happens by the process of osmosis. The movement of water across cell membranes is also an example of osmosis.

Some key points about osmosis are:

• It is a passive process that happens without any expenditure of energy.
• It involves the movement of molecules from a region of higher concentration to lower concentration until the concentrations become equal on either side of the membrane.
• Any solvent can undergo the process of osmosis including gases and supercritical liquids.
• Osmosis is a form of passive transport.
• The movement of water across cell membranes is an example of osmosis.

In summary, osmosis is a process by which the molecules of a solvent pass from a solution of low concentration to a solution of high concentration through a semi-permeable membrane. It is a form of passive transport that happens without any expenditure of energy and is crucial for the survival of living organisms.