Question

A circulatory system is said to be closed when blood flows through tubes called blood vessels.

• A. True
• B. False

Answer 1

The correct option is A True

True. A circulatory system is said to be closed when the blood flows only through a network of blood vessels, like in humans. Open circulatory system is present in animals like cockroaches where blood flows through body cavity. No blood vessels are present in these animals.