NEET BIOLOGY

Detailed explanation-1: -Mammals are warm-blooded animals with four-chambered heart. They derive their name from the presence of mammary glands. They have hair on their body along with sweat and oil glands.

Detailed explanation-2: -Hair is present in differing degrees on all mammals. On adult whales, elephants, sirenians, and rhinoceroses body hair is limited to scattered bristles. In most other mammals the hair is abundant enough to form a thick coat, while humans are among the most hairless of all mammals.

Detailed explanation-3: -Warm-blooded animals with hair or fur are called mammals. Humans are mammals, as are dogs, horses, elephants, and tigers.

Detailed explanation-4: -The Taxonomy System. Kingdom Animalia is the largest of the five existing kingdoms on Planet Earth. The scientific classification system is divided into seven major groups, (1) kingdom, (2) phylum or division, (3) class, (4) order, (5) family, (6) genus, and (7) species.

Detailed explanation-5: -All mammals have hair. It is one of their defining biological characteristics. However, there are a few species with hair so reduced by evolution that they actually appear to be naked.