Describe the important characters of mammals and birds. Give two examples of each.

Characters of Mammals:

(i) Mammals are warm-blooded animals.

(ii) They have four-chambered heart.

(iii) They have mammary glands for the production of milk to nourish their young.

(iv) Their skin has hairs as well as sweat and oil glands.

(iv) They have two pairs of limbs, adapted for walking, running, climbing, burrowing, swimming or flying.

(v) Respiration is by lungs.

(vi) Sexes are separate and fertilisation is internal.

Examples- Whale and human beings.

Characters of birds:

1. These are warm-blooded animals and most of them can fly except flightless birds.

2. Forelimbs are modified into wings for flying.

3. The hind limbs generally have scales and are modified for walking, swimming or clasping the tree branches.

4. Body is light as they have hollow (pneumatic) bones.

5. Body is streamlined to reduce air resistance during flight.

6. Flights muscles are well developed.

7. Body is covered with exoskeleton of water-proof and light-weight feathers.

8. Heart is four-chambered.

9. Respiration is by lungs.

10. They have actue vision.

11. Sexes are separate. Fertilisation is internal.

12. They are oviparous.

Example- Pavo (Peacock), Columba (Pigeon), Corvus (Crow).