Question

Haemocoel is found in
(A) Hydra
(B) Cockroach
(C) Earthworm
(D) Snake

Answer 1

Hint: Haemocoel is found in the insect which is of the order Blattodea. These insects have compound eyes and long flexible antennae. They are usually present at our houses or offices as a pest.

Complete step by step answer:
Haemocoel is the body cavity of the cockroach. It is known as haemocoel as the body cavity of the cockroach is filled with the haemolymph. The blood of the insects is known as haemolymph. Haemolymph is mostly colorless i.e it is whitish in color or appears as a transparent solution.
In cockroaches, there are 13 segments in the heart out of which 10 chambers or units are arranged
dorsally, and the rest 3 units or chambers are in the thoracic region. The Periplaneta americana is the largest species of cockroach which is commonly found around us. Hemolymph contains blood cells which are Hemocytes, Plasmocytes, and Coagulocytes. The blood does not flow through the vessels. They come in direct contact with the tissue. The haemocoel is subdivided by a transverse pericardial membrane into two cavities. The dorsal cavity is called the pericardial cavity (sinus) , and the ventral cavity as the perivisceral cavity.
So, the correct answer is ‘Cockroach’.

Note: Circulatory system of cockroach is present on the dorsal side with 10 abdominal and 3 thoracic units of heart. The first chamber of the heart opens into the aorta. Oxygenated blood enters into each chamber through an Ostia. Once blood enters into each chamber, there are chances of backflow of blood which is guarded by auricular valves.