Question

Cockroach blood does not contain respiratory pigment. It means

• A. It does not respire
• B. Cockroach respires anaerobically
• C. Oxygen passes to all the tissues through diffusion
• D. Oxygen reaches tissue through tracheoles

Answer 1

Answer: (D)

Oxygen reaches tissue through tracheoles

The exchange of gases occur at the tissue level and so it is called as tissue or internal respiration. Fine terminal branches of the trachea, the tracheoles end blindly in the tissues. The cellular matrix of the trachea is filled with granules of pigments which store oxygen, as well as terminal part of tracheoles, contain a fluid having dissolved oxygen. The fluid in the tracheoles advances or retreats in relation to the changes in the osmotic pressure of the surrounding tissue fluid, hemolymph.
So, the correct answer is option D.