Q. Which among the following has open circulatory system? I. Cockroach II. Human III. Prawn
Answer: I and III
Notes: Cockroach and prawns have open circulatory system in which the blood is not confined within blood vessels. The blood bathes the organs and tissues directly. Open circulatory systems pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells. Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood. The open circulatory system is common to molluscs and arthropods.