The nymph of a cockroach is known as:

In which of the following is the wings vestigial?

Spiracles found in cockroach are $:-$ (in $pairs$)

Mark the odd one in each series:
Maxilla; mandible; labrum; antennae

Which of the following statement$(s)$ is/are correct?
$(i)$ Cockroaches are brown or black bodied animals that are included in class $Insecta$ of phylum $Arthropoda$.
$(ii)$ Males bear a pair of short,thread-like anal styles which are absent in females.
$(iii)$ The heart of a cockroach consists of an elongated muscular tube lying along the mid-dorsal line of the thorax and abdomen.
$(iv)$ The nymph grows by moulting about $13$ times to reach the adult form.

The tongue-like structure present in $Periplaneta$ is known as: