Question

Which of the following gases reduces the oxygen carrying capacity of blood?

• A. Carbon monoxide
• B. Carbon dioxide
• C. Sulphur trioxide
• D. Nitrogen dioxide

Answer 1

The correct option is A Carbon monoxide

When we breathe, oxygen present in the air combines with hemoglobin present in the blood to form oxyhemoglobin. This oxyhemoglobin is then transferred to various body parts where it again dissociates to release oxygen. If large amount of carbon monoxide is present in inhaled air, it forms carboxyhemoglobin as the affinity of carbon monoxide is 325 times greater than oxygen.