The given diagram shows air sacs and associated blood vessels in the human lung. The concentration of carbon dioxide is the highest in the part labelled as
Correct answer: B. B
- A. A
- B. B
- C. C
- D. D
Explanation
The only artery with greater CO₂ concentration is the pulmonary artery, as it carries deoxygenated blood, so B is correct. The pulmonary vein has a greater O₂ concentration. Capillary beds facilitate gaseous exchange. So A, C, and D are incorrect.
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: