question_answer 15)

Respiration in Insects is called direct because (a) the cells exchange  directly with the air in the tubes (b) the tissues exchange  directly with coelomic fluid (c) the tissues exchange  directly with the air outside through body surface (d) tracheal tubes exchange  directly with the haemocoel which then exchange with tissues

Answer:

                (a) Insects have a network of tubes (tracheal tubes) to transport atmospheric air within the body. These openings lead to trachae. The cells exchange  directly with the air in the spiracles present on insects body