Which of the following structures does the given figure represent?

Respiratory exchange in earthworms takes place through __

How can we distinguish the ventral surface of the earthworm by their dorsal surface?

Earthworm consists of an open type of circulatory system.

In how many segments is the body of cockroach divided?

What are cuboidal or columnar cells called when they bear cilia?

Which of these structures do not help in excretion in cockroaches?

Which of these is characteristic of hindwings of a cockroach?