Botany - Animal Kingdom Question with Solution | TestHub

Class Pisces is divided into two groups: Chondrichthyes and Osteichthyes. Chondrichthyes are cartilaginous fishes. These have a ventral mouth, placoid scales while air bladder and operculum are absent. Thus they differ from Osteichthyes. These do not show 5-7 pairs of gill slits. Cyclostomatas are chordates with circular mouth but jaws are absent and hence are known as Agnathas. Class Aves belongs to tetrapods in which fore limbs are modified into wings. All mammals have mammary glands, hair on body and two pairs of limbs. All mammals have pinnae except aquatic mammals.