Page 3 - 2.Lesson Notes -Animalia-vertebrata

Aves

• All birds belong to this class.
• They are warm-blooded, have a four-chambered heart and breathe through
lungs.
• They have their forelimbs modified into wings which help in flight.
• Jaws are modified into beaks.
• Bones are hollow and most of them are fused to reduce body weight.

• An exoskeleton is in the form of feathers.

Mammalia

• They are warm-blooded, breath through lungs and have a four-chambered
heart.
• Presence of hair on their body, sweat and oil glands are exclusive characters
of mammals.
• Presence of pinna i.e external ear is also seen only in mammals.
• They also have the mammary glands to feed their young ones.

• They usually give birth to live young ones.
• Examples: humans, cattle etc