Body Fluids And Circulation Ques 70
70. Which one of the following has an open circulatory system?
(a) Periplaneta
(b) Hirudinaria
(c) Octopus
(d) Pheretima
Show Answer
Answer : a
Hints & Solutions
(a) Periplaneta (P. americana, the Indian Cockroach) is an insect & insects do not have closed blood circulation. Their blood (called haemolymph) even does not serve for respiration. They do not possess blood vessels in this circulatory system and hence it is an open system.