BIOL 202 Practical 2: Phylum Chordata

Phylum Chordata

fish/amphibians/reptiles/mammals, 5 shared characteristics, 3 subphyums

Dorsal hollow nerve cord, notochord, pharyngeal gill slits, endostyle, postanal tail

5 shared Chordate characteristics

Dorsal hollow nerve cord

develops into central nervous system, brain, and spinal cord (Chordata)

Notochord

provides skeletal support to Chordates

Pharyngeal gill slits

strains food particles from water in Chordates

Endostyle

mucus secreting tissue in Chordates

Postanal tail

Mostly for propulsion in Chordates

Subphylum Cephalochordata

Chordata: lancelets where the adults have all 5 chordate features

Subphylum Tunicate

Chordata: lancelets where the larvae only have all 5 chordate features

Subphylum Vertebrata

Chordata: 5 chordata characteristics seen in ancestors, cranium/vertebral column/endoskeleton

Cranium

protective housing for brain (Subphylum Vertebrata)

Vertebral Column

protects nerve cord (Subphylum Vertebrata)

Vertebrate Endoskeleton

can be bone or cartilage and grouped depending on this

Class Myxini

Vertebrata: hagfish, jawless fish w/ slime defense

Class Chondrichthyes

Vertebrata: sharks/rays, boneless jawed fish, cartilaginous endoskeleton and no swim bladder

Class Actinopterygii

Vertebrata: jawed fish with bones, ray-finned fish

Class Sarcopterygii

Vertebrata: jawed fish with bones, lobe-finned fish

Class Amphibia

Vertebrata: frogs/salamanders, tetrapods, require water for moisture, ectothermic, respire through skin

Ectothermic

cannot control internal body temp (Amphibia and most Reptilia)

Class Reptilia

Vertebrata: turtles/lizards/birds, tetrapod amniotes, amniotic egg, desiccation skin, ectothermic (not birds)

Tetrapods

has four legs (Amphibia, Reptilia, Mammalia)

Tetrapod amniotes

has four legs and an egg that has an inner, outer, and fetal membrane (Reptilia and Mammalia)

Endothermic

Can control internal body temp (birds and Mammalia)

Amniotic eggs

egg with specialized membranes so it can develop the embryo away from water

Class Mammalia

Vertebrata: mammary glands, hair, endothermic

Hair/fur

provides insulation/camouflage/defense for mammals

Mammary glands

Produces milk in mammals