Body Fluids and Circulation Question 69
69. 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.
