The amount of oxygen in exhaled air is _.
Correct answer: B. 16%
- A. 21%
- B. 16%
- C. 79%
- D. 4%
Explanation
The amount of oxygen in exhaled air is 16% whereas in inhaled air it is 21% as the body absorbs oxygen for aerobic respiration to occur.
Last updated
About Gaseous Exchange in Lungs
Gaseous exchange in the lungs occurs across the thin, moist alveolar and capillary surfaces, where oxygen and carbon dioxide diffuse down partial pressure gradients. The topic covers alveolar adaptations, ventilation, the role of haemoglobin in oxygen transport, carbon dioxide carriage, and the difference between external gas exchange and cellular respiration.
Practise Respiration
446 free Respiration MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Biology questions like this
Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
About 70% of the carbon dioxide is carried in blood as:
All characteristics of Hemoglobin EXCEPT:
An increase in carbon dioxide concentration makes haemoglobin release oxygen more readily. This is known as
Approximately seventy percent of carbon dioxide absorbed by the blood will be transported to the lungs
As the pH of blood decreases, H+ ions increase, which combine with the protein part of hemoglobin to reduce its ability to bind with: