LIFE SCIENCE

Detailed explanation-1: -Passive transport requires no energy input, as compounds are able to move freely across the membrane based only on a favourable concentration gradient (Figure 1.11).

Detailed explanation-2: -Diffusion is a passive process which means it does not require energy. Small particles diffuse faster than large ones. Eg substances like oxygen, carbon dioxide and glucose move in and out of cells by diffusion. The greater the difference in concentration, the faster the rate of diffusion.

Detailed explanation-3: -Passive diffusion, therefore, requires no energy expenditure by the cell; it is not saturable or subject to competition between molecules.