Question

What is true about RBCs in humans?

• A. They do not carry CO2 at all
• B. They carry about 20-25 percent of CO2
• C. They transport 99.5 percent of O2
• D. They transport about 80 percent oxygen only and the rest 20 percent of it is transported in dissolved state in blood plasma

Answer 1

The correct option is B

They carry about 20-25 percent of CO2

About $97\%$ of O2 is transported by RBCs in the blood. The remaining $3\%$ of O2 is carried in the dissolved state through the plasma. Nearly $20-25\%$ of CO2 is transported by RBCs, whereas $70\%$ of it is carried as bicarbonate