What is true about RBCs in humans?
Correct answer: A. They carry about 20-25 percent of CO2
- A. They carry about 20-25 percent of CO2
- B. They transport 99.5 percent of O2
- C. They transport about 80 percent oxygen only and the rest 20 percent of it is transported in dissolved state in blood plasma
- D. They do not carry CO2 at all.
Explanation
All options are explained below: a)They carry about 20-25 percent of CO2 (Correct Option): Red blood cells (RBCs) play a significant role in carrying and transporting carbon dioxide (CO2) in the blood. About 20-25 percent of the CO2 produced in the body is transported by RBCs. This transport occurs in multiple forms, including the conversion of CO2 to bicarbonate ions (HCO3-) within RBCs and the binding of CO2 to hemoglobin as carbamino compounds. RBCs help facilitate the removal of CO2 from body tissues to be transported to the lungs for exhalation. B. They transport 99.5 percent of O2: This statement is not accurate. While RBCs are responsible for transporting oxygen (O2) in the blood, they do not transport 99.5 percent of it. The majority of oxygen in the blood is carried by hemoglobin within the RBCs, but there is also some dissolved oxygen in the blood plasma. C. They transport about 80 percent oxygen only, and the rest 20 percent of it is transported in dissolved state in blood plasma:This statement is more accurate. RBCs are responsible for transporting approximately 97-98 percent of oxygen, while the remaining 2-3 percent is carried in a dissolved state in the blood plasma. The majority of oxygen binds to hemoglobin within RBCs. D. They do not carry CO2 at all:This statement is not accurate. RBCs do carry carbon dioxide (CO2), primarily in the form of bicarbonate ions (HCO3-) and carbamino compounds. They play a crucial role in CO2 transport from body tissues to the lungs for exhalation. Summary: The correct option (A) accurately describes the role of RBCs in transporting CO2. They carry about 20-25 percent of the CO2 produced in the body. In addition to CO2, RBCs also play a significant role in transporting oxygen (O2), with approximately 97-98 percent of O2 being carried by hemoglobin within RBCs, while a small percentage is dissolved in the blood plasma. The other options either inaccurately represent percentages or claim that RBCs do not participate in CO2 transport.
Last updated
About Respiration
The human respiratory system includes the air passages, lungs, alveoli and breathing muscles, while gaseous exchange explains how oxygen enters blood and carbon dioxide leaves it by diffusion. The effects of smoking include damage to cilia and alveoli, reduced gas exchange, chronic bronchitis, emphysema and increased risk of lung cancer.
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
A cavity bounded by the ribs and diaphragm is called:
A disease caused by gradual breakdown of the thin walls of alveoli is:
A large proportion of oxygen remains unused in the human blood even after its uptake by the body tissues. This O2 _.
A large proportion of oxygen remains unused in the human blood even after its uptake by the body tissues. This O2 _.
A surfactant is essential for: