One of the following organisms exhibits a closed and single circulatory system ____________
A. Insect B. Earthworm C. Fishes D. Mammals
Correct Answer: C
Explanation
Closed circulatory system is a type of circulatory system whereby blood is contained within vessels while open circulatory system is the one when the heart pumps blood out into a blood vessel which branches into cavities called haemocoels. Closed circulatory system is found in higher animals while open system is found in insects.