When we close our nose and mouth we couldn't be able to breathe then how plants inhale CO2 and exhale O2 when leaves fall in autumn season?
Answers
Answer:Think of it this way:
The atmosphere contains several gasses. A fire burns due to an oxidation reaction, which required Oxygen. How does only Oxygen get separated here?
It doesn't! Oxygen is used up, and the rest just remains there.
A similar occurrence happens where breathing is concerned. When we inhale air, all the other gases present in it also enter our lungs. We have no selective mechanism to inhale only oxygen. In the terminal region of lungs, the alveoli, an exchange of gases takes place. The Haemoglobin in RBCs has an affinity for this oxygen present(Due to the iron contained in the Haemoglobin) in the inhaled air and it is immediately absorbed. The remaining gases are inert (with respect to the blood's constituents) which are sent out during exhalation.
Explanation: