Question

What is true about RBCs in humans?

• A. They carry about 20-25 per cent of ${CO}_2$
• B. They transport 99.5 per cent of $O_2$
• C. They transport about 80 per cent oxygen only and the remaining 20 per cent of it is transported in dissolved state in blood plasma
• D. They do not carry ${CO}_2$ at all

Answer 1

The correct option is A They carry about 20-25 per cent of ${CO}_2$

Oxygen and carbon dioxide are circulated across the body through the blood in different forms. Nearly 70% of carbon dioxide is carried by the blood as bicarbonate, 20-25% as bound to RBCs, and around 7% in a dissolves state through plasma. However, in the case of oxygen, nearly 97% is transported by RBCs (as bound to haemoglobin), while the remaining 3% is carried in a dissolved state through the plasma.