MammalsHave hairAbility to nourish their young with milkBreathe air4-chambered heartEndotherms

EnvironmentLive in a wide variety of ecosystems Land, water, and flying mammals

Food SourceMust eat 10 times as much food as a reptile to

maintain body heatUse jaws and teeth to eat (Specialized teeth)Digestive tract absorbs nutrients for the body to use

Maintaining Homeostasis - Internal(Circulation, Respiration, Excretion)

lungs to breatheHave a diaphragm- powerful muscle2 separate loops in circulatory system and a 4-

chamber heartKidneys help maintain homeostasis by filtering urea

from the blood as well as by excreting excess water or retaining needed water

Maintaining Homeostasis - External(Response)

Highest developed brainCerebral cortex- center of thinking and other

complex behaviorsHighly developed senses to detect and respond to

stimuli from their external environment

MovementBackbone that flexes both vertically and side to

side.Very flexibleMove in a variety of ways depending on their

lifestyleReproductionInternal fertilizationFeed on mother’s milkMost care for their youngDuration of care varies among species

Evolutionary MilestoneEndotherm, Hair, mammary glands, breathe air, 3

middle-ear bones

Picture and Vocabulary

Picture on page 827, Fig 32-7 – homologous structures

Vocabulary: mammary gland (821), cerebral cortex (825)