NEETZoologyBreathing and Exchange of Gases
Given below are the physiological steps involved in the elimination of carbon dioxide from the human body: (A) Transport of CO ₂ by the blood. (B) Release of CO ₂ by the cells resulting from catabolic reactions. (C) Diffusion of CO ₂ across the alveolar membrane into the alveolar cavity. (D) Diffusion of CO ₂ from the tissues into the blood. (E) Pulmonary ventilation by which CO ₂ rich alveolar air is released out. S
Options
- A(E), (C), (A), (D), (B)
- B(B), (D), (A), (C), (E)
- C(B), (C), (A), (D), (E)
- D(B), (A), (D), (C), (E)
Correct answer
B. (B), (D), (A), (C), (E)
Step-by-step solution
The elimination of carbon dioxide follows the reverse path of oxygen uptake. The correct chronological sequence begins with the production of CO ₂ during cellular catabolism (B). This CO ₂ then diffuses from the tissues into the bloodstream (D). The blood transports the CO ₂ to the lungs (A). At the lungs, CO ₂ diffuses across the alveolar membrane into the alveolar cavity (C). Finally, pulmonary ventilation expels the CO ₂ -rich alveolar air to the exterior (E). Thus, the correct sequence is (B), (D), (A), (C), (E