the characteristic features of class-Aves are  I. they are warm-blodded and oviparous.
Channel: Doubtnut
Date: 2020-05-03

the characteristic features of class-Aves are  I. they are warm-blodded and oviparous. ltb rgt II.they have pneumatic bones.  III. Syrinx is not present.  IV. Fertilisation is external.  Choose the correct option.