In cockroach,nephrocytes are concerned with

Malpighian tubules remove excretory products from:

In female cockroach,the $7^{th}$,$8^{th}$,and $9^{th}$ sterna form a genital pouch. Which of the following pairs of sterna are primarily involved in forming the brood or genital pouch?

Which of the following organisms has "ommatidia" as the unit of its eye?

Which of the following statement$(s)$ is/are correct regarding the digestive system of cockroach?
$(i)$ Mouth opens into a short tubular pharynx,leading to a narrow tubular passage called oesophagus.
$(ii)$ Gizzard helps in grinding the food particles.
$(iii)$ $A$ ring of $6-8$ blind tubules called hepatic or gastric caecae is present at the junction of foregut and midgut,which secrete digestive juice.
$(iv)$ At the junction of midgut and hindgut is present another ring of $100-150$ yellow coloured thin filamentous Malpighian tubules which help in removal of excretory products from haemolymph.

Give scientific reasons: In cockroach,a well-developed respiratory system is seen.