Animal Kingdom-X
Analysis of various PMTs from 2011-201520112012201320142015AIPMT/NEET43843AIIMS2316AMU25418Kerala4549K.CET4211J & K6412CLASS MAMMALIA
• Mammals are the highly evolved and most important group in animal kingdom.
• They belong to the class Mammalia (L. mamma, breast), and possesses mammary
glands for the production of milk with which they nourish their young ones.
• They are primarily terrestrial vertebrates, but some are aquatic, e.g., whales.
• They occur in all sorts of habitats from the polar regions to the tropics including
the dense forests and driest deserts.
• They are dominant animals today and have the capacity to learn because of their
better developed brain.
• The mammals have evolved from therapsids (mammal-like reptiles) like Dimetrodon
in triassic some 200 million years ago in the jurassic period, before the first birds.generAL ChArACterS
• Hair-clad, mostly terrestrial, air-breathing, warm-blooded, viviparous, tetrapod
vertebrates.
• The body is divisible into head, neck, trunk and tail.
• There are two pairs of pentadactyl limbs variously adapted for walking, running,
jumping, climbing, burrowing, swimming or flying. Hindlimbs are absent in
cetaceans and sirenians.
• Exoskeleton includes lifeless, horny, epidermal hair, spines, scales, claws, nails,
hoofs, horns, bony dermal plates, etc.
• Endoskeleton is bony. Skull is dicondylic, i.e., having two occipital condyles.
• Vertebrae are acoelous. Cervical vertebrae are seven in number with variation of
6-9 in sloth and manatee. Ribs are bicephalous.• Skin richly glandular containing sudoriparous (sweat), sebaceous (oil) and
sometimes scent glands in both the sexes.
Class XI