O₂ and CO₂ Exchange in Tissues — NEET Biology
📚 Practice ConceptDiffusion of O₂ and CO₂ between blood and tissues.
Assertion (A): Gas exchange occurs only between alveoli and blood. Reason (R): The alveolar surface provides the primary site for oxygen and carbon dioxide diffusion.
View solution & NCERT explanation
Correct answer: D — If the assertion is false but the reason is true.
NCERT states “Exchange of gases also occur between blood and tissues” - the qualifier “also” indicates gas exchange occurs in MULTIPLE locations, not only at alveoli. Assertion is false by removing “also.” NCERT confirms alveoli are primary gas exchange sites - Reason is true. Tests whether students know gas exchange occurs at both alveolar and tissue levels.
What does NCERT say about Diffusion O and CO?
Has this concept appeared in NEET?
Which chapter is this from?
Through deep analysis of NEET and NTA, 176 of the 180 ReNEET 2026 (June 21) questions were already in the MedicNEET question bank before the exam.
176/180MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.