Describe the important characters of mammals and birds. Give two examples of each.
Characters of birds:-
(i) Forelimbs are modified into wings.
(ii) The body is covered with feathers and scales.
(iii) Mammary glands are absent.
(iv) A toothless beak is present.
(v) Skin is dry only, a single preen gland is present.
(vi) A diaphragm is absent.
(vii) Bones of birds are hollow or pneumatic.
(viii) Larynx of birds is non-functional.
(ix) Lungs contain external air sacs.
(x) Birds are oviparous.
Example: Crow and peacock.
Characters of mammals-
(i) Wings are absent except in bats.
(ii) Feathers and scales are absent. Hair is present.
(iii) Females have mammary glands.
(iv) Teeth are present. Jaws do not form beak.
(v) Skin bears a number of sweat and oil glands.
(vi) Diaphragm is present.
(vii) Bones of mammals do not have air cavities.
(viii) Larynx of mammals is functional.
(ix) Lungs do not have external air sacs.
(x) Mammals are viviparous.
Example: Human beings and monkeys.