Question

Open blood circulatory system is found in
A. Earthworm
B. Cockroach/ Prawn
C. Humans
D. Cows

Answer 1

Hint: Open blood circulatory system is that in which blood is pumped by heart into the body cavity that allows blood to bathe the tissue and then return back to the heart. In a closed circulatory system there is a system of vessels that works not directly the body cavities.

Complete answer: In this open blood circulatory system the blood flow is sluggish. In this blood is pumped directly into the cavities by the heart where tissue is surrounded by the blood. There is no role of blood vessels in the open blood circulatory system.

> Option A- Earthworm: Earthworm has a closed blood circulatory system. In an earthworm blood is circulated through blood vessels. The aortic arches, dorsal blood vessels, and ventral blood vessels are the three main blood vessels in the blood circulatory system of the earthworm.

> Option B- Cockroach/ Prawn: Cockroaches have an open blood circulatory system. In cockroaches blood is pumped by the heart directly into the cavity. There are organs floating in the blood that get the nutrition directly from the blood. There is a separate closed type respiratory system in the cockroaches that provide independent oxygen supply.

> Option C- Humans: In humans, the blood circulatory system is closed and is well managed by the heart. There is a proper blood vessel system that helps in the circulation of the blood to each organ and cell sufficiently and then brings back deoxygenated blood to the heart for oxygenation by the lungs.

> Option D- Cows: Cows have a closed circulatory system like that of humans.

Hence, the correct answer is option (B).

Note: Open circulatory system directly bathes tissue and organs. It is present in arthropods and mollusks. There is no capillary system and transport of gases doesn’t occur. There are no respiratory pigments present and blood flow is slow.