Question

double circulation and its necessary

Answer 1

Ans. During a single cycle blood goes twice in the heart which is known asdouble circulation. It is necessary in human being to separate oxygenated and de-oxygenated blood because this makes their circulatory system is more efficient and helps in maintaining constant body temperature.

Answer 2

hey..

If the blood reaches the heart twice in a single cycle then it is called double circulation

ex. humans

Double circulation is important because the blood should reach the heart as once the deoxygenated blood collected from all the parts of the body and then as the oxygenated blood should be transported to all the parts of the body