General Characteristics of Mammals Flashcards
general characteristics of mammals
mother produces milk for young, mammary gland
in general, brain, parental care is greatly advanced
skin glands: sweat, sebaceous, mammary
quadruped: 4 limbs
presence of hair
exceptions of quadrupeds
whales, dolphins, manatees
are there any completely hairless mammal species?
no, even dolphins have hair when they are young
functions of hair
insulation
camouflage
protection form abrasion, sunburn
sensory organs (whiskers)
communication: announce presence, communicate social information, sexual differences (ex. white tailed dear, skunk markings, male vs female lion mane)
epiphyses
plates at top and bottom of bone, limit final growth
skeletal differences from lower vertebrates
epiphyses
attachment of skull and mandible (attached jaw)
mammals only animal with teeth set in sockets (except crocodiles)
diaphragm
important for breathing
separates abdomen from thoracic cavity to prevent mixing of microbiomes between digestive system and heart/lungs
mammalian anatomical characteristics
lungs hang freely in chest
4 chambered heart
homeothermic
most viviparous, ova small and nearly yolkless (similar to reptile/amphibian)
monotremes
3 species: platypus, 2 species of echidna
oviparous (lay eggs) but still produce milk for young, have hair
marsupials
approx 280 species (ex. opossum, kangaroo)
viviparous, young attached by primitive placenta
short gestation, continues in marsupium (pouch)
viviparous mammals
all other mammals (approx 4300 species)
true placental animals
importance of placenta (2)
mother can’t pass infection to developing baby
no reaction if different blood types
placenta
tissue developed from embryo
parallel to uterine wall
side-by-side vascular systems so nutrients and waste can transport across
eating habits of mammals
carnivores: cats, dogs, ferrets
herbivores: gerbils, rabbits
omnivores: mouse, rat
diurnal mammals
active during the day: dogs
