Question

Number of spiracles in cockroach is
A. 6 pairs
B. 8 pairs
C. 10 pairs
D. 12 pairs

Answer 1

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

Complete step by step answer:
In cockroaches and other insects, the respiratory system consists of a network of trachea. The
respiration occurs through the spiracles. These are the fine openings present in the body of
cockroach. The exchange of gaseous takes place through spiracles. It enters the tracheal system via.
Spiracles and diffuses through the tissues and the cells.
These spiracles are present in numerous pairs. Like in case of cockroach, 10 pairs of spiracles are
present in the lateral side of the exoskeleton. Out of this 10 pairs 2 are present in the thoracic region
and 8 are present in the abdomen.

Thus the correct answer is C. 10 pair of spiracles is present in cockroach.

Additional Information: Several aquatic animals have spiracles which are guarded by hairs. This
closure or hairs prevent water and dust from entering the tracheal system.

Note:
In the respiratory system of cockroach, spiracles are similar to nostrils, trachea is similar to
Human trachea and alveolus are similar to tracheoles in cockroaches. In cockroach 10 pair of spiracles is
present. Out of which two are present in thorax and 8 are present in the abdomen region.