The gizzard of a cockroach is a part of which system?

The fat body in cockroach contains .........

Which secretion is responsible for the characteristic pungent odor in cockroaches?

What is the similarity between the trachea of a cockroach and a rabbit?

Which of the following statement$(s)$ is/are correct regarding the respiratory system of a cockroach?
$(i)$ It consists of a network of trachea that open through $12$ pairs of small holes called spiracles present on the lateral side of the body.
$(ii)$ Thin branching tubes carry oxygen from the air to all the parts.
$(iii)$ The opening of the spiracles is regulated by sphincters.
$(iv)$ Exchange of gases takes place at the tracheoles by diffusion.

Excretion in cockroach is performed by all,$EXCEPT$ :