Question

The body cavity of cockroach is called as
A) Pseudocoel
B) Coelom
C) Haemocoel
D) Hydrocoel

Answer 1

Hint: Body cavity is the space inside the body of the animal which is filled with fluid. The body cavity is formed in between the intestinal canal and the body wall which is lined with mesodermal cells. Cockroaches are true coelomates. Their body is filled with fluid that serves as a blood vascular system.

Complete answer:
To solve this question, we must first understand the structure and function of body cavity in cockroaches.
The body of the cockroach is long, elongated and compressed dorsoventrally. The body is covered by a hard exoskeleton which protects the delicate organs inside the cockroach. The body is divided into the head thorax and abdomen.
The body of the cockroach consists of true coelom. It means that the body contains a cavity which is present in between the digestive system and the body wall. In the case of cockroaches, the cavity is filled with a blood-like fluid. This cavity is known as haemocoel. The blood vascular system of cockroaches is not well developed. The blood vessels do not open into capillaries rather they are in direct contact with the tissues. As a result of this the circulation rate is lowered.
Pseudocoel- This kind of cavity is found in the invertebrates or nematodes. The body cavity lacks the epithelial lining of the mesodermal cells.

The correct answer is option A.

Note:
Haemolymph is a blood like fluid which functions in transporting hormones, nutrients and metabolites. It does not flow in the vessels rather it comes in direct contact with the tissues. It is not red in colour as it does not contain RBCs so does not function in transport of oxygen.