Give reasons for the following : (a) Echidna and Platypus lay eggs but are considered as mammals. (b) Crocodile has four chambered heart but still is a reptile. (c) Birds have pneumatic bones

CBSE Class 9 CBSE Class 9 Science
1

(a) Echidna and Platypus lay eggs but are warm-blooded and feed their young ones with milk.
(b) Crocodile is cold-blooded reptile.
© To make the body light for flight.