The colleterial glands in a cockroach help in .....

Identify the odd one out.

Each ovary in a cockroach is formed by a group of $8$ ovarian tubules or ovarioles,containing a chain of developing ova. Fill in the blank.

Consider the following statements regarding cockroach and mark the correct option.
$(i)$ Head is formed by the fusion of $6$ segments.
$(ii)$ Mouth parts are biting and chewing type.
$(iii)$ Crop is the part of midgut.

Describe the respiratory system of a cockroach.

Explain the nervous system of a cockroach.