'श्वसन' (Respiration) में कौन सी गैस ली जाती है?

उत्तर: (D) ऑक्सीजन — Respiration: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy. O₂ is inhaled, CO₂ is exhaled. Photosynthesis is the reverse process. Aerobic respiration needs O₂; anaerobic (fermentation) doesn't.