Q. Which one of the following has an open circulatory system ?
A) Pheretima
B) Periplaneta
C) Hirudinaria
D) Octopus
Explanation
[Solution from source] Periplaneta (cockroach), like other arthropods, has an open circulatory system with blood flowing through haemocoel sinuses. Pheretima, Hirudinaria and Octopus have closed systems. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.