Question

In mammals oxygenated and deoxygenated blood is kept on separate why

Answer 1

because they need large amount of oxygen for energy that's why

Answer 2

Explanation:

It is necessary to separate oxygenated and deoxygenated blood to maintain efficient supply of oxygen into the body. This system is essential in animals that have high energy need. For example, animals like mammals and birds which constantly use this energy to maintain their body temperature.