Which of the following statement(s) is/are correct regarding respiratory system of cockroach ?
- It consists of a network of trachea, that open through 12 pairs of small holes called spiracles present on the lateral side of the body.
- Thin branching tubes carry oxygen from the air to all the parts.
- The opening of the spiracles is regulated by sphincters.
- Exchange of gases take place at the tracheoles by diffusion.
Only (i)
(i), (ii) and (iii)
(ii), (iii) and (iv)
All of these
