Question

what is sternum and tergum in cockroach

Answer 1

A given tergum may be divided into hardened plates or sclerites commonly referred to as tergites. ... In crustaceans, the tergum is known as a pleuron when it overhangs the insertion of the limb on each side as a free plate. In contrast to the tergum, the ventral portion of a segment is called the sternum.
The sternum or breastbone is a long flat bone located in the center of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Shaped roughly like a necktie, it is one of the largest and longest flat bones of the body. Its three regions are the manubrium, the body, and the xiphoid process.[1] The word "sternum" originates from the Greek στέρνον, meaning "chest".

Answer 2

Answer:

The body of an arthropods like cockroach is covered by exoskeleton called sclerites. The exoskeleton (sclerites) on the dorsal surface is known as Tergum plural Terga and the exoskeleton rings present on the ventral side is called Sternum plural sterna.