Mammals Flashcards
What does heterodont teeth mean?
has multiple different types of teeth
What are guard hairs?
exterior protection, pigmentation
What are underhairs?
interior insulation
What are vibrissae?
- aka whiskers
- a type of stiff, functional hair used by mammals to sense their environment
what does monotreme mean?
mammals that lay eggs
what is a gestation period?
time before birth
what are the general characteristics of mammals?
- hair
- mammary glands nourish young
- placenta nourishes embryo
- advanced mental capabilities (learning + memory)
- heterodont teeth
- endothermic
How is hair growth different than feathers?
bird feathers grow and die while mammal hair continues to grow, dying only at the far end as it grows
How do horns and antlers differ?
horns: single + unbranched + extensions of the skull + not temporary
antlers: branched + grow from the skull + temporary
How is a rhinoceros horn different from other horns?
composed of compacted keratin fibers rather than having a core of bone + continually grow
what are the types of glands that characterize mammals?
exocrine glands
- sweat glands
- scent glands
- sebaceous glands
mammary glands
What are the types of teeth that characterize mammals?
- incisors
- canines
- premolars
- molars
what are incisors used for?
biting + severing
what are canines used for?
piercing + tearing
what are premolars used for?
shearing + crushing
what are molars used for?
grinding + crushing
what are deciduous or milk teeth?
temporary baby teeth
Which GI tract is longer and why (carnivore or herbivore)?
herbivore bc the cell wall of plant material makes it much harder to digest
why is a ruminant stomach different than ours?
able to make the enzyme cellulase
what is the gestation period of monotremes?
no gestation period
what is the gestation period of marsupials?
brief gestation period
what is the gestation period of placental mammals?
long gestation period
how are the young of monotremes nourished?
nursed
how are the young of marsupials nourished?
embryos absorb nutrients briefly from uterine wall
how are the young of placental mammals nourished?
embryo nourished in uterus via placenta
what animals are monotremes?
platypus + spiny anteaters
what animals are marsupials?
kangaroos + wallabies + apossums
