Solved UPSC CDS/OTA Question
A solved UPSC CDS/OTA PYQ - decoded step-by-step.
Solve it the standard way once - then learn the shortcut.
Q · Respiratory System medium · 45s
The largest surface area for gas exchange in the lungs is provided by:
TopicRespiratory System
Question Typemultiple choice
Difficultymedium
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
Every step explained - no skipped algebra.
Alveolar ducts and saccules lead to alveolar clusters where most gas exchange occurs. Their walls are lined with alveoli, providing the extensive surface (~70 m²) needed for efficient O₂/CO₂ diffusion.
Final Answer: Option B - Alveolar ducts and saccules