The (nine) Characteristics of MAMMALS By Samara Nix

Hair…… Made out of an keratin, is thought to have evolved from scales Hair for mammals provide insulation and water proofing (conserves body heat) But also use a method of panting to cool down by using sweat glands Panting releases water from the lungs which results in loss of body heat

Nursing…. Mammals have organs called glands that secrete various substances needed by the animals Gland- is an organ that secretes substances inside or outside the body Mammals have several kinds of glands Including ones that produce saliva, sweat, digestive enzymes, and hormones The feed there young through mammary glands In females mammary glands secrete milk a liquid that is rich in fat, sugar, protein, minerals, and vitamins Mammals nurse their young until they are mature enough to find food

Teeth Although fish and most reptiles have teeth, their teeth are use for tearing, grasping, and holding prey Mammals have different kinds of teeth adapted to the type of food they eat >Pointed incisors- are used by predators to grasp and hold prey >Chisel-like incisors- are modified for gnawing >Canines- are used by predators such as lions and tigers to puncture and tear flesh >Premolars and Molars- are used for slicing, grinding, and crushing Many hoofed animals (cows, horses, etc) have an adaptation known as cud chewing that enables them to break down the cellulose of the plant cell wall into nutrients

Modified limbs This is an adaptation that enables mammals to meet there required energy levels needed Examples: food gathering, in some groug such as primates with the opposable thumb grasping and holding objects,

Learning Mammals intellegence is a result of a complex nervous system and highly developed brain Because they know survival skills mammals are able to guard their young very fiercefully Mammals can accomplish complex behaviors, such as learning and remembering what they have learned Primates such as humans are the most intteligent mammals Primates for example can use tools

The Diaphragm Mammals need a high level of energy for heating and cooling their bodies, as well as for locomotion This energy level is sustained when large amounts of oxygen enter the body and reach all the cells One thing that enables this in mammals is the diaphragm that expands and contrast the chest cavity Diaphragm-is the sheet of of muscle located beneath the lungs The diaphragm seperates the chest cavity from the abdominal cavity, where other organs are located

Four Chambered Hearts Mammals like birds have 4 chambered hearts So that oxygenated blood is keep away from the deoxygenated blood this ensures that mammals receive a good supply of oxygen to support their endothermic metabolism

Endothermic Mammals are endothermic They have the ability to maintain a fairly constant body temperature Which enables them to live in almost every possible environment