Gaseous Exchange in Plants and Animals

Living organisms require energy to perform cellular activities. The energy comes from breakdown of food in respiration.

Carbon (IV) oxide is a by-product of respiration and its accumulation in cells is harmful which has to be removed. Most organisms use oxygen for respiration which is obtained from the environment.

Photosynthetic cells of green plants use carbon (Iv) oxide as a raw material for photosynthesis and produce oxygen as a byproduct. The movement of these gases between the cells of organisms and the environment comprises gaseous exchange. The process of moving oxygen into the body and carbon (Iv) oxide out of the body is called breathing or ventilation.

Gaseous exchange involves the passage of oxygen and carbon (IV) oxide through a respiratory surface. Diffusion is the main process involved in gaseous exchange.