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26 terms

Bio Chapter 34, part 1

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Notochord
flexible, sturdy rod along length of animal, between nerve cord and gut
Nerve cord
nervous tissue (a.k.a. spinal cord)
Pharyngeal slits
the pharynx portion of the gut opens to the outside
Muscular tail
the body extends beyond the anus
urochordata
subphylum, do not have a true backbone, but they have the characteristics of other chordates (ex. tunicates, sea squirts)
vertebrates
do have a true backbone (vertebrae), spinal cord is enlarged at one end (brain)
fish
oldest vertebrate fossils, lacked a jaw
agnatha
jawless vertebrates, could not chew food, used pharyngeal slits, gills, 500 mil years ago (ex. lamprey)
fish jaw
major evolutionary step for fish, gills became hardened with cartilage, could eat big pieces of food
cartilaginous fish
fish that used cartilage as the hard substance for skeleton
fish bones
second big step for fish, cartilage became hardened due to presence of calcium salts (calcium phosphate)
vertebrae, jaws, lungs, limbs
what fish gave us
amphibians
first vertebrates to move on land (evolved from lungfish), increased use of limbs, dependence on oxygen
amphibians
first tetrapods, mostly carnivorous, cold-blooded (ectoderms), longer snout, mobile neck, highly flexible
buccal pumping
no operculum, large gular plates, breathes air (ex. frogs do this when their throats get big and small)
frog development
eggs laid in water, then tadpoles develop and breathe with gills, skin of adults must be moist at all times (limited habitats)
amniotes
reptiles, birds, and mammals, amniotic sac allows them to be fully terrestrial
eggs
amnion membrane (protection), chorion membrane (gas exchange), allantois sac (waste disposal), yolk sac (nutrients)
amniotes
evolved from amphibians, live in drier habitats, skin covered in keratin protein for protection, ectothermic but they regulate temp
dinosaurs
large terrestrial reptiles from 300-65 mil years ago, diverse lifestyles, very agile/fast, mass extinction at end of cretaceous period
birds
evolved from dinosaurs, scales on legs only, honeycomb bones, very good eyesight, endothermic
social characteristics of birds
controlled flight, complex courtship rituals, social bonding/ extended parenting, amazing navigation skills using sun/moon/stars
Tiktaalik
genus of extinct sarcopterygian (lobe-finned "fish")
Panderichthys
exhibits transitional features between lobe-finned fishes and early tetrapods
Chondrichthyes
jawed fish, paired fins (ex. sharks, sting rays)
cephalochordata
subphylum of chordata, presence of a notochord (ex. lancelets)