NEET2026ZoologyBreathing and Exchange of GasesActual
In humans, respiration occurs in the following steps. Arrange these steps in the correct order. A. Diffusion of O ₂ and CO ₂ between blood and tissues. B. Diffusion of O ₂ and CO ₂ across alveolar membrane. C. Pulmonary ventilation by which atmospheric air is drawn in and CO ₂ rich alveolar air is released out. D. Cellular respiration. E. Transport of gases by the blood. Choose the correct answer from the options giv
Options
- AA, B, C, D, E
- BE, A, C, D, B
- CC, B, E, A, D
- DC, A, B, E, D
Correct answer
C. C, B, E, A, D
Step-by-step solution
The steps of respiration in humans occur in the following sequence: First, pulmonary ventilation (breathing) takes place, by which atmospheric air is drawn in and CO ₂ rich alveolar air is released out (C). Second, diffusion of gases ( O ₂ and CO ₂ ) occurs across the alveolar membrane (B). Third, transport of gases is carried out by the blood (E). Fourth, diffusion of O ₂ and CO ₂ takes place between the blood and tissues (A). Finally, cellular respiration occurs, where O ₂ is utilised by the cells for catabolic r