Differentiate the nature of skin in four classes of tetrapoda.

The nafure of skin in four classes of tetrapoda are:

(i) Class Amphibia –moist skin without scales.

(ii) Class Reptilia – Dry and cornified skin having epidermal scales or scutes.

(iii) Class Aves – Dry skin without glands.

(iv) Class Mammalia - Glandular skin with hairs.