MCQ
Respiration in insects is called direct because:
- ✓The cells exchange $O_2/ \ce{CO_2}$ directly with the air in the tubes.
- BThe tissues exchange $O_2/ \ce{CO_2}$ directly with coelomic fluid.
- CThe tissues exchange $O_2/ \ce{CO_2}$ directly with the air outside through body surface.
- DTracheal tubes exchange $O_2/ \ce{CO_2}$ directly with the haemocoel which then exchange with tissues.
