Question

Respiration in insects is called direct because

• A. the cells exchange $O_2/CO_2$ directly with the air in the tubes
• B. the tissues exchange $O_2/CO_2$ directly with coelomic fluid
• C. the tissues exchange $O_2/CO_2$ directly with the air outside through body surface
• D. tracheal tubes exchange $O_2/CO_2$ directly with the haemocoel which then exchange with tissues

Answer 1

Answer: (A)

the cells exchange $O_2/CO_2$ directly with the air in the tubes

Answer 2

Respiration in insects is independent of its coelomic fluid. They respire by a tracheal system and the cells exchange $O_2/CO_2$ directly with the air in the tubes. So, the correct answer is 'the cells exchange $O_2/CO_2$ directly with the air in the tubes'.