Breathing and Exchange of Gases Question 29
29. The exchange of gases in the alveoli of the lungs takes place by
(a) simple diffusion
(b) osmosis
(c) active transport
(d) passive transport
Show Answer
Answer : a
Hints & Solution
(a) Gaseous exchange between blood (dissolved phase) and alveolar air (gaseous phase) across respiratory membrane occurs by simple diffusion. Obviously, it depends upon the concentration gradient (=partial pressure) of the concerned gases in blood and alveolar air.
