Answer:
Gas exchange
Step-by-step explanation:
Trachea and gills are part of the respiratory system in organisms. These structures serve in gas exchange. The process of gas exchange removes carbon dioxide and allows oxygen gas to enter the body.
Aerobic cellular respiration is the efficient process of ATP synthesis as it produces the maximum number of ATPs by complete oxidation of nutrients. The process of aerobic cellular respiration needs the presence of oxygen.
Hence, Animals have a variety of adaptations, including trachea and gills, which allow gas exchange to occur. Gas exchange provides the oxygen necessary for cellular respiration and efficient ATP synthesis.