A Representative Study of Mammals
Mammals are the highly evolved animals. They form the most diversified group that can be found in almost all habitats, such as hilly areas, aquatic regions, deserts, forests, polar regions and swamps.
Characteristic features of mammals
The two most important features that separate mammals from other vertebrates are
1. Presence of hairs on the body
2. Presence of mammary glands
• Hairs: Hairs are out-growths from the skin. They help to prevent loss of body heat. The colour and pattern of hairs on various animals usually matches their background of their surroundings. Hairs serve various purposes in different animals. For example, porcupines and hedgehogs have spiny, stiff and long hairs, called quills, all over their body, which protect them from predators.
• The whiskers of cats and dogs are sensitive to touch. Hairs on the body of polar bears keep them warm and provide heat insulation.
• Hairs and nails are made up of the protein keratin. It is a protein that our digestive system cannot digest.
Mammary glands: Mammary glands are milk-producing glands that secrete milk to feed the young ones.
They are modified sweat glands that are present in both males and females but are functional and fully developed only in females.
• Warm-blooded animals or homeotherms: Animals whose body temperature remains constant even if their surrounding temperature fluctuates are called warm-blooded animals.
Examples: Mammals such as human beings, whales and polar bears.
• The body temperature of humans remains between 98.4°F and 98.6°F.
• Mammals are able to maintain a constant body temperature through the heat produced by the burning of food during digestion and throu…
To view the complete topic, please