PhylumChordata

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Chordates

•  Characterizedby–  anotochord,–  ahollowdorsalnervecord,and–  pharyngeal(throat)slits

•  Somechordatespossesthesecharacteris=csasadults;othersasonlyembryos;butallhavethematsomestageoflife

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Organiza=on•  3Sub-phyla– SubphylumUrochordata•  Tunicates– smallmarinechordates– filterfeeders

•  notochordanddorsalnervecordpresentinthetadpole-shapedlarvaeonly

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Organiza=on•  SubphylumChephalochordata–  Lancelets–  smallfishlikecreatures–  LiveinsandyboHomsofshallowtropicaloceans

–  Adultlanceletshaveadefinitehead–  Filterfeeders

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Organiza=on•  SubphylumVertebrata– Fish,Amphibians,etc.–  Notochordreplacedbythevertebrae(backbone)

–  Twopairsofappendages–  Closedcirculatorysystemwithaventralheart

–  Vetebralcolumnsurroundsandprotectsthedorsalnervecord

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SubphylumVertebrata•  Advantagestohavingvertebrae:–  Providesbodywithstructureandsupportwhileallowingflexibility.

–  ProvidesaHachmentsitesformuscles

–  Protectsthenervecord

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Vertebrates•  Sevenclasses–  Fish

•  Agnatha•  Chondrichthyes•  Osteichthyes

– Amphibia–  Rep=lia– Aves– Mammalia

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Fish•  ClassAgnatha–  Jawlessfish

•  Longeel-likebody•  Circularmouth•  2-chamberedheart•  Noscales•  Nopairedfins•  Nobones•  Havenotochordsasadults•  Ectothermic

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Vertebrates•  ClassChondrichthyes–  Car=lagenousfish

•  Ex.Sharks,skates,etc.•  Jaw•  2-chamberedheart•  Tough,smallscales•  Pairedfins•  Car=lagenousendoskeleton•  Ectothermic

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Evolu=onaryAdvances•  Jaws– Madeitpossibleto

•  Eatlargerorganisms,and•  Defendthemselvesby“bi=ng”

•  Pairedfins–  pectoral(anterior)andpelvic(posterior)•  Allowsformorecontrolovertheirmovementinwater

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Vertebrates•  ClassOsteichthyes

–  Bonyfish•  Ex.Tuna,salmon,etc.•  Jaw•  2-chamberedheart•  Scales•  Pairedfins•  Bonyendoskeleton•  Gills•  Swimbladder•  Ectothermic

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Evolu=onaryAdvances•  Importantadapta=onsofbonyfishes–  Swimbladder

•  regulatesbuoyancy–  Laterallinesystem

•  assessesrateofmovementthroughwateraspressurewavesagainstthelateralline

– Operculum(Gillcover)•  flexingtheoperculumpermitsbonyfishtopumpwaterovertheirgills

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Amphibians•  Amphi=both;bio=life•  Larvaearefish-likeandaqua=c.•  Adultsareterrestrial.

–  Requiremoistenvironment•  Smallestgroupofliving

vertebrates.•  Havemoistslimyskinthat

containsmanyglands•  Noscalesandclaws.•  Webbedfeet.•  Ectothermic

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Evolu=onaryAdvances•  Movementontoland– Lungs

•  Madeitpossibletobreatheonland

– Limbswithstrongerbones•  Supportbodyweight

– 3-chamberedheart14

ClassRep=lia•  Dryskincoveredwithscales.•  Lungs•  3chamberedheart•  Toesandclaws•  Ectothermic•  LayAMNIOTICeggs

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Evolu=onaryAdvances•  Movementontoland– Dryskin–  Scales–  Respiratorymuscles– Amnio=cegg

•  Allowsfordryreproduc=on

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ClassAves•  Dryskincoveredwithfeathers.–  Scalesonfeet.

•  Wings•  Lungs•  4chamberedheart•  Bipedal–  Toesandclaws

•  Endothermic•  LayAMNIOTICeggs

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Evolu=onaryAdvances•  WingsandFeathers–  Flight

•  PorousBones–  Reducesweight

•  VeryefficientRespiratorysystem

•  Endothermic–  Ac=veinallclimatecondi=ons

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Feathers•  Threetypesoffeathers:– Contour•  Largefeathersthatcoverthebodyandwings•  Flightfeathers

– Down•  Growunderneathandbetweenthecontourfeathers•  Insulatethebird

– Powder•  Importantforwaterbirdsforwaterproofing.

•  Preeningiswhenbirdsgroomtheirfeathers.

•  Mol=ng(sheddingoffeathers)inlatesummer

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ClassMammalia•  Diversegroupoforganisms•  Sizevariesfrom=nybumblebeebattolargebluewhales

•  Endothermic–  Excellenttemperatureregula=on

•  Mostareviviparous

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Evolu=onaryAdvances•  Dryskincoveredwithfur.•  Mammaryglands•  Subcutaneousfatfor

insula=on.•  Diaphragm•  Sweatglands•  Specializedteeth

–  Incisors–  Canines–  Premolars–  Molars

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