Mechanisms of breathing vary among different groups of animals depending mainly on their habitats and levels of organisation. Identify the incorrect match between the animal group and its respiratory structure.

Step-by-step solution

Lower invertebrates like sponges, coelenterates, and flatworms exchange O₂ with CO₂ by simple diffusion over their entire body surface. They do not possess specialized respiratory structures like gills. Earthworms use their moist cuticle for respiration. Insects have a network of tubes called tracheal tubes to transport atmospheric air within the body. Special vascularised structures called gills are used by most aquatic arthropods and molluscs. Therefore, the match between flatworms and gills is incorrect. Answer: