Question

The terga, sterna and pleura of cockroach body are joined by
A. Arthrodial membrane
B. Cartilage
C. Cementing glue
D. Muscular tissue

Answer 1

Hint: Cockroaches are among the most primitive living insects. It is characterized by a flattened oval body bearing a shining black or brown integument. The head is bent downwards and contains mouth parts, compound eye and long thread like antennae. The body is covered with a covering.

Complete answer:
The cockroaches are commonly called as insects and they bear a small, dorsoventrally flattened body. The head is small with large compound eyes and two ocelli and slender, long and flexible sensory antennae. The body is further divided into thorax, which is segmented and abdomen. THe thorax consists of three segments and the abdomen bears ten distinct segments.
The external surface is covered by a thick covering or known as the exoskeleton. The exoskeleton forms a protective covering over the body and protects the body from any external shocks. THe covering of the exoskeleton is made up of calcium carbonate and has a coating of wax like substances that repels water. The exoskeleton is made up of hardened plates that are known as the sclerites. The sclerites cover the complete body of the cockroaches.
Each segment of the exoskeleton contains four separate sclerites that are joined with the help of an arthrodial membrane. It is also called an articular membrane and is elastic in nature.
The dorsal sclerites are known as the tergite while the sclerites present on the ventral portion are known as sternite. The sclerites that are present on the lateral side of the body are known as pleuritis.

Hence, the correct answer is option (A).

Additional information:
The phylum Arthropoda is characterized by the joint legs and presence of an exoskeleton. The exoskeleton in Arthropods are tough and resilient. It is also known as integument. It is usually made up of chitin and calcium carbonates. The chitin becomes stiff and is reinforced in some parts of the body and finally gets hardened by materials such as minerals and proteins. The exoskeleton provides the body an additional elasticity and rigidity.

Note: In cockroaches, an outer covering of the body is present which is known as the exoskeleton. It is made up of four parts for each of the segments of the body. The tergite, sternite and the pleurite are the different types of sclerites that are joined together by an arthrodial membrane. The arthrodial membrane is elastic in nature.