How many spiracles are present in a cockroach (in $pairs$)?

Name the blood vessel that arises from the first chamber of the heart in a cockroach.

$A$: In cockroach,inspiration is a passive process.
$R$: Expansion of abdominal cavity allows the space for expansion of the tracheal trunk,as a result,air enters through the spiracle.

In the given diagram of the circulatory system of a cockroach,what does $P$ represent?

Which is correct for mosaic vision?

The blood of a cockroach contains no respiratory pigment. This means that: