MAMMALS MAMMALS CHARACTERISTICS Warm blooded Hairfur Subcutaneous fat

MAMMALS MAMMAL’S CHARACTERISTICS Warm blooded Hair/fur Subcutaneous fat Sweat glands Viviparous- gives birth to live young who develop inside the female Feed young with milk produced in the mammary glands Teeth that fit their feeding/eating habits A well developed respiratory system and a four chamber heart EVOLUTION OF MAMMALS endothermic and ectothermic Monotremes: Egg laying mammals- duckbill platypus and spiny anteater Marsupials: Young develop inside a pouch- kangaroo, opossum Placental Mammals: Young develop inside female

FORM & FUNCTION FEEDING Teeth made to fit eating habits Sharp claws on feet Bodies built for sudden bursts of speed Produce bursts of sound waves to stun nearby fish Rumen: part of the digestive tract for animals to digest cellulose “Chewing their cud” fig. 33 -6 Cecum: dead-end sack of some herbivores (rabbits) to digest cellulose Vampire bats, Blue whale (baleen) RESPIRATION Use lungs powered by two sets of muscles; diaphragm INTERNAL TRANSPORT A circulatory system w/ a 4 -chambered heart & lungs to bring oxygen

FORMS & FUNCTION EXCRETION Highly developed kidneys to extract nitrogenous & other wastes Excrete or retain excess liquids, salts, sugars, & other compounds RESPONSE Brains developed w/3 parts: cerebrum, cerebellum, and medulla Cerebrum- complicated behaviors, thinking & learning Cerebellum- coordinates movement Medulla- regulates body functions such as breathing & heart rate Highly developed senses Eyes: color and black and white Ears set for different frequencies Smell and Taste Protection- Herbivores and Carnivores

FORM & FUNCTION REPRODUCTION Monotremes reproduce much like reptiles Oviparous: female lays eggs and incubated outside mom’s body, but after the young hatch, mom feeds milk produced by mammary glands Marsupials are viviparous and bear live young. But yolk sac inside mom isn’t enough to nourish through development, so young are born very premature and must finish development inside the pouch (marsupium) Placentals are nourished much longer inside the womb by a placenta. Nutrients, oxygen, co 2, and wasted are exchanged through the placenta. Gestation period is the time the embryo stays inside the uterus. Ranges from a few weeks (mice) to two years (elephant) The amount of time spent after birth with the parents vary from specie to specie. Why? ?