Question

what is the need of respiratory pigments in large multicellular animals

Answer 1

There is the need for respiratory pigment ( haemoglobin) in large multicellular animals because they pick up the oxygen in the lungs from the air we breathe in. the oxygenated blood is then circulated in the body and gets deoxigenated, and gives back carbon dioxide.

Answer 2

Answer:

In multicellular organism, the diffusion pressure alone cannot take care of oxygen delivery to all parts of the body, instead respiratory pigment present in blood take up oxygen from the air in the lungs and carry it to tissues which are deficient in oxygen.