Class 11 NEET Biology Structural Organisation in Animals

(b) : There are 10 pairs of spiracles in cockroach. Two pairs are thoracic in which first pair is known as mesothoracic, lying infront of the mesothorax between the bases of first and second pair of legs and are the largest. The second pair is called metathoracic. Abdominal spiracles are eight pairs. The first pair is dorsal in position and lies on the lateral margins of the first abdominal tergum. The remaining are situated on the sides of their corresponding segments on the pleura between the terga and sterna. Spiracles are meant for intake of fresh air and release of foul air.