Which one of the following classes is incorrectly matched with its two general characters? Class Characteristics (i) Amphibia Urinary bladder present, fertilization external (ii) Chondrichthyes Air bladder, operculum (iii) Cyclostomata Closed circulation, 6-15 pairs of gill slits (iv) Reptiles Cornified skin, direct development

Step-by-step solution

Chondrichthyes are cartilaginous fish. They include shark, rays etc. These Chondrichthyes lack operculum, which is external covering on the gills and they also lack air bladder because of which they have to swim constantly to avoid sinking. Operculum and air bladder are found in all of the Osteichthyes (bony fish).