Question

What are differences between the following:
(a) Cartilaginous fishes and bony fishes
(b) Amphibia and Reptilia;
​(c) Aves and mammals.

Answer 1

(a)

Cartilaginous fishes	Bony fishes
Their skeleton is made entirely of cartilage.	Their skeleton is composed partly or wholly of bones.
E.g., torpedo, shark, etc.	E.g., tuna, sea horse, etc.

(b)

Amphibia	Reptilia
They have dual mode of life − larva is aquatic, while the adult is terrestrial.	They can be terrestrial or aquatic. The aquatic forms return to land in order to lay eggs.
Scales are absent.	Body is covered with scales.
They lay eggs on water.	They lay eggs on land.

(c)

Aves	Mammals
They lay eggs.	They give birth to young ones.
They have feathers.	They have fur or hair.
They feed their young ones by regurgitating partially digested food.	They feed their young ones through mammary glands.