The figure given below shows the male reproductive system of a cockroach. Identify $P$,$Q$,and $R$.

In cockroach,which of the following is the principal motor centre?

Which of the following structures originates from the ectoderm?

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

Which of the following does not participate in excretion in cockroach?

Which of the following statement$(s)$ is/are correct about the nervous system of a cockroach?
$(i)$ It consists of a series of fused segmentally arranged ganglia joined by paired longitudinal connectives on the ventral side.
$(ii)$ There are six ganglia lie in the thorax,and three in the abdomen.
$(iii)$ The sense organs are antennae,eyes,maxillary palps,labial palps,and anal cerci,etc.
$(iv)$ Each eye consists of about $5000$ hexagonal ommatidia.