Respiration in Animals and Plants — BIOLOGY STD 7 — Question

Amphiiians like adult frogs can breathe through their moist skin, lungs and mouth cavity. When a frog is in water, oxygen enters through the skin and passes into blood capillaries underneath the skin. This exchange of gases through the skin is called cutaneous respiration. On land, adult frogs breathe through their mouth cavity and lungs. Lungs are small balloon-like organs into which oxygen-rich air is forced through mouth cavity and the nostrils. Oxygen is absorbed from the air by the lining of the mouth and lungs and carbon dioxide is given out. Tadpoles live in water and hence breathe through their gills until they grow into adult frogs.