Answers

2016-03-30T11:06:14+08:00
In a closed circulatory system the blood flows within blood vessels like arteries and veins wherein the blood is being pushed by the pressure exerted by the heart. while in an open circulatory system like the insects, the oxygen enters  through a tube that opens directly to the outside of the body and is delivered directly to the tissues and for blood that carries nutrients, it freely flows through the body of the insect
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