Q. Which one of the following statements is incorrect?
A) The residual air in lungs slightly decreases the efficiency of respiration in mammals
B) The presence of non-respiratory air sacs, increases the efficiency of respiration in birds
C) In insects, circulating body fluids serve to distribute oxygen to tissues
D) The principle of countercurrent flow facilitates efficient respiration in gills of fishes
Explanation
Residual air is the air that remains in lungs after the most forceful expiration. It is about 1200 mL. As the residual air remains in the lungs, therefore, it has no effect on respiration efficiency.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.