PART - 2 - Unit V : CH - 14 Breathing and Exchange of Gases — BIOLOGY STD 11 Science — Question

Following are the five characteristics of the respiratory organs:
1. The surface of the respiratory organs being extremely thin so that they can exchange gases easily.
2. The respiratory surface always remains moist and a network of condensed blood cells is spread on the respiratory surface.
3. The respiratory surface is extremely wide and is involved in gaseous exchange.
4. Presence and carrying of pure air (oxygenated) to the respiratory surface.
5. Existence of respiratory tract for gaseous exchange and presence of respiratory pigment or haemoglobin as a carrier substance for carrying O₂.