Question

How many pairs of spiracles are found in a cockroach?
(A) 6 pairs
(B) 8 pairs
(C) 10 pairs
(D) 12 pairs

Answer 1

Hint: Spiracles are specialized parts that help in the Respiratory activity of cockroaches and are present on the sides of the organism’s body. They act as a valve that paves the way to the respiratory system.

Complete answer:
Cockroaches possess 10 pairs of spiracles which help in respiratory action. These are the small openings on the sides of the body which serve as muscular valves paving the way to the respiratory system. The actual respiration occurs by the trachea which is a system of tubes attached to the spiracles on all body segments. When the $CO_2$ level inside rises, valves on the spiracle open and the $CO_2$ diffuses out and oxygen diffuses in.

Additional Information:
Cockroaches are insects of the order Blattodea and they possess specialized body structures and are commonly studied in laboratories. There are 4,600 species of cockroaches found on Earth of which 5 species are well-known pests of the human household.
These insects are generally omnivores that commonly feed on a variety of foodstuff including bread, fruit, leather, paper, glue, hair, dead insects, wood, etc. As mentioned in the answer part, they breathe through the trachea and the finest tracheoles bring the air directly to each cell. They use pheromones to attract mates. They carry out mating by facing away from each other with their genitalia in contact and copulation can be prolonged.

So, the correct answer is "10 pairs".

Note:
Cockroaches are found almost everywhere in the world, especially in the tropics and subtropics. They are unique in the way that they do not possess lungs for respiration and continue to respire even if their head is removed. In some species, breathing may occur by the rhythmic movement of the body musculature to forcibly move air in and out of the spiracle.