Carbon dioxide is transported in blood mainly as:

Ans. B. Bicarbonatea. The solubility of carbon dioxide in blood is about 20 times that of oxygen , so that there is considerably more carbon dioxide than oxygen in simple solution at equal partial pressures.b. The carbon dioxide that diffuses into RBCs is rapidly hydrated to H2 CO3 because of the presence of carbonic anhydrase.c. The H2 CO3 dissociates to H+ and H2 CO3 , and the AH+ is buffered, primarily by hemoglobin, while the HCO3 - enters the plasma 'Some' of the carbon dioxide in the ABCs reacts with the amino groups of proteins principally hemoglobin, to form carbamino compounds.