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): Total Lung Capacity (TLC) and Functional Residual Capacity (FRC) can be directly measured using a simple clinical spirometer. Reason (R): A simple spirometer cannot measure the Residual Volume (RV), which is a necessary component of both TLC and FRC. In the light of the above statements, choose the
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A)
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
- C(A) is true but (R) is false
- D(A) is false but (R) is true
Correct answer
D. (A) is false but (R) is true
Step-by-step solution
Assertion (A) is false because a simple clinical spirometer can only measure the volume of air that can be breathed in and out. It cannot measure the air that remains in the lungs after forceful expiration. Reason (R) is true. Residual Volume (RV) is the volume of air remaining in the lungs even after a forcible expiration, meaning it never enters the spirometer. Since Total Lung Capacity (TLC) and Functional Residual Capacity (FRC) both include RV in their composition (TLC = Vital Capacity + RV, and FRC = Expirato