The diffusion of water across a selective permeable membrane is called what

The diffusion of water across a selective permeable membrane is called osmosis.

Explanation:

Osmosis can be described as the movement of water molecules from an area of higher concentration to an area of lower concentration through a selectively permeable membrane. As the water molecules tend to move along the concentration gradient, hence the process of osmosis is a type of passive transport. Very little or no energy will be required for the process of osmosis to occur.

In contrast, during the process of active transport, molecules move against a concentration gradient and hence require energy.