AIIMS 2018 Zoology Biology MCQ Question

The correct answer is A) Carbaminohaemoglobin because carbon dioxide (CO2) binds to hemoglobin (Hb) primarily at the amino groups of the protein, forming carbamino compounds. This process facilitates CO2 transport from tissues to the lungs, where it is released. In contrast, carboxyhaemoglobin (B) refers to hemoglobin bound to carbon monoxide (CO), while oxyhaemoglobin (C) is hemoglobin bound to oxygen, and methhaemoglobin (D) is an oxidized form of hemoglobin.