Question

Which one of the following has an open circulatory system
A. Octopus
B. Pheretima
C. Periplaneta
D. Hirudinaria

Answer 1

Hint: Open circulatory systems are a system of transport of blood without the blood vessels. In an open circulatory system, blood is not confined to the blood vessels and flows into spaces called sinuses in the tissues, it is termed as the open circulatory system.

Complete answer:
The circulatory patterns are two major types: open circulatory system and closed circulatory system. In open circulation, blood flows at low pressure, and the exchange of materials is direct between blood and body cells. It is less efficient as the volume of the blood flowing to different tissues and organs cannot be regulated according to the need. Periplaneta comes under the phylum Arthropoda. Arthropods have an open blood circulatory system, therefore Periplaneta also has an open circulatory system.
Octopus belongs to order Sepia. Organisms belonging to sepia are mollusks but they have a closed circulatory system. Therefore octopuses have a closed circulatory system.
Pheretima belongs to the phylum Annelids. Annelids have a closed circulatory system.
Hirudinaria is also known as Indian leech and belongs to the phylum Annelids. Hirundinaria also has a closed circulatory system.
So, the correct answer is (C).

Note: Closed circulatory system is a closed network of vessels in which blood circulates. When the blood pumped by the heart is circulated through a closed network of blood vessels, it is called a closed circulatory system. Blood flows at high pressure and the exchange of materials occurs through the tissue fluid. It is more efficient as the flow can be precisely regulated.