Q. Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
Mammals and birds are warm blooded animals. This means they can control their body temperature and don’t have to depend on environment for their body temperature regulation. Because of this birds and mammals require optimum oxidization of glucose which would be possible with good supply of oxygen. By developing four chambered heart they have made it possible to completely segregate the oxygenated and deoxygenated blood in their bodies which is their need because of their habit and habitat.