VPY-0042
QUESTION
The mean thickness of respiratory membrane in bird is?
OPTIONS
(A) More than that in mammals
(B) Equal to that in mammals
(C) Less than that in mammals
(D) Thinner at corner points and thicker at another
ANSWER
(C) Less than that in mammals
EXPLANATION
Less than that in mammals is the correct option because the avian respiratory membrane is exceptionally thin, facilitating rapid diffusion of gases across the parabronchial blood-air barrier. A greater thickness would hinder diffusion, equality with mammals would not reflect the highly efficient avian exchange system, and the final option is not the standard physiological description.