Question

Number of spiracles found in Cockroach are
(A) 5 thoracic, 3 abdominal
(B) 3 thoracic, 5 abdominal
(C) 8 thoracic, 2 abdominal
(D) 2 thoracic, 8 abdominal

Answer 1

Hint: Spiracles are the small opening on the lateral side of the body thru which air enters the tracheal system. It is similar to nostrils in function.

Complete answer:
In cockroaches and different insects, the respiratory system consists of a community of trachea. The respiration takes place through the spiracles. These are the excellent openings existing in the physique of cockroaches. The exchange of gaseous takes location through spiracles.

It enters the tracheal gadget via. Spiracles and diffuses thru the tissues and the cells. These spiracles are existing in numerous pairs. Like in the case of cockroaches, 10 pairs of spiracles are existing in the lateral side of the exoskeleton. Out of this 10 pairs 2 are present in the thoracic region and 8 are existing in the abdomen. These spiracles help in the respirations. These are sensory organs present in the cockroach.
Several aquatic animals have spiracles which are guarded by means of hairs. This closure or hairs stop water and dirt from entering the tracheal system.

Hence the correct answer is option ‘D’.

Note: In the respiratory device of cockroach, spiracles are comparable to nostrils, trachea is similar to Human trachea and alveolus are similar to tracheoles in cockroaches. In the cockroach 10 pairs of spiracles are present. Out of which two are present in thorax and eight are current in the stomach region.