Question

The process by which a solvent passes through a selectively or differentially permeable membrane in an opposite direction, when subjected to a pressure greater than the osmotic pressure is

• A. simple diffusion
• B. osmosis
• C. reverse osmosis
• D. facilitated diffusion

Answer 1

The correct option is C reverse osmosis

The process by which a solvent passes through a selectively or differentially permeable membrane in a direction opposite to that of natural osmosis, when subjected to a pressure greater than the osmotic pressure is known as reverse osmosis.
Simple diffusion is the random movement of molecules from their higher concentration to their lower concentration (along the concentration gradient) until equilibrium is attained. It is a slow process. Substances that are being transported across the plasma membrane must be lipid soluble. It is independent of the living system. It occurs only for short distances. It is a passive process, i.e. there is no consumption of ATP. Movement of gases in plants occurs through simple diffusion.
Osmosis is a type of simple diffusion of water molecules. The diffusion of water molecules occurs across a selectively or differentially permeable membrane. At equilibrium, both sides of the semi permeable membrane have equal water potential and solute potential (if the membrane allows the solute to pass).
Facilitated diffusion is the passive (there is no consumption of ATP) transport of molecules across a concentration gradient that is performed with the help of specialized proteins. Movement of lipid insoluble substances across the plasma membrane occurs through facilitated diffusion. It is highly specific to the molecules being transported. The specialized proteins transport a few molecules at a time across the membrane rather than a bulk transport. It is sensitive to inhibition.