NEETZoologyBreathing and Exchange of Gases
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The diffusion of CO ₂ from tissues into the systemic blood is independent of the cellular utilisation of O ₂ . Reason (R): Catabolic reactions in the cells continuously consume O ₂ and release CO ₂ , creating a partial pressure gradient between tissues and systemic capillaries. In the light of the
Options
- ABoth Assertion and Reason are correct and Reason is the correct explanation of Assertion.
- BBoth Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
- CAssertion is correct but Reason is not correct.
- DAssertion is not correct but Reason is correct.
Correct answer
D. Assertion is not correct but Reason is correct.
Step-by-step solution
Assertion (A) is not correct because the diffusion of CO ₂ from tissues into the blood is directly driven by the cellular utilisation of O ₂ . Reason (R) is correct. During cellular respiration, catabolic reactions continuously consume O ₂ and release CO ₂ . This metabolic activity increases the partial pressure of CO ₂ ( p CO ₂ ) in the tissues compared to the systemic capillaries, creating the concentration gradient necessary for the passive diffusion of CO ₂ into the blood. Thus, Assertion is not correct but Rea