Why don't humans and other mammals have tracheal respiration because they possess trachea?
Is it because the final gas exchange occurs at the alveoli? So humans and other mammals are said to have pulmonary or alveolar respiration? Please explain.
Respiration through tracheae is called tracheal respiration. It is seen in insects centipedes, ticks, some mites and spiders. The respiratory pigments are absent in blood because the tracheal system distributes O2 or air directly to the cells.