英語版動(dòng)物世界introductiontoanimals

IntroductiontoAnimalsCharacteristicsMulticellularOrganizationHeterotrophicSexualreproductionanddevelopmentMovementAnimalClassesMammalsPeoplearemammals..Soaredogs,cats,horses,duckbillplatypuses,kangaroos,,dolphinsandwhales..Whatdoalltheseanimalshaveincommon,youask?Theansweris–MILK!Ifananimaldrinksmilkwhenitisababyandhashaironitsbody,,itbelongstothemammalclassMammalsareoneofthe6mainclassesofanimals..Animalclassesaregroupsofanimalsthatscientistsconsidertobealikeinsomeimportantways..Mammalsaretheanimalclassthatpeoplebelongto.Thereareonlyabout4,000kindsofmammals.Warm-bloodedBirdsBirdsareanimalsthathavefeathersandthatarebornoutofhard--shelledeggs.Somepeoplethinkthatwhatmakesananimalabirdisitswings..Batshavewings..Flieshavewings.Batsandfliesarenotbirds.Sowhatmakesananimalabird?Theanswerisfeathers!Allbirdshavefeathersandbirdsaretheonlyanimalsthatdo.Thefeathersonabird’’swingsandtailoverlap.Becausetheyoverlap,,thefeatherscatchandholdtheair.Thishelpsthebirdtofly,,steeritselfandland.FishFisharevertebratesthatliveinwaterandhavegills,,scalesandfinsontheirbody.Therearealotofdifferentfishandmanyofthemlookveryoddindeed..Thereareblindfish,fishwithnoseslikeelephants,fishthatshootdownpassingbugswithastreamofwaterandevenfishthatcrawlontolandandhopabout!!ReptilesReptilesareaclassofanimalwithscalyskin.Theyarecoldbloodedandarebornonland.Snakes,,lizards,,crocodiles,,alligatorsandturtlesallbelongtothereptileclass.AmphibiansAmphibiansareborninthewater.Whentheyareborn,theybreathwithgillslikeafish.Butwhentheygrowup,theydeveloplungsandcanliveonland.ArthropodsArthropodsisahugephylumofanimals---itincludeselevenanimalclasses::Merostomata,Pycnogonida,Arachnida,,Remipedia,Cephalocarida,Branchiopoda,Maxillopoda,Malacostraca,Chilopoda,,Diplopoda,andInsecta..Anyanimalsthathavemorethanfour,,jointedlegsarearthropods.Insects,,spidersandcrustaceansallbelongtothisclassofanimals.ZoologistArachnologistCarcinologistConchologistEntomologistHerptologistIchthyologistMalacologistMammalogistOrnithologistPaleozoologistMarinebiologistbotanistMulticellularOrganizationMostanimalscontainlargenumbersofcells.Humanscontain50trillioncells.Inmostanimals,,thereisadivisionoflabor..Specializationistheadaptationofacellforaparticularfunction.Tissuesaretheorganizationofcells.Cellareabletoorganizebythejoiningofcellsbycelljunctions.Cellspecializationhasallowedorganismstoevolveandadapttomanyenvironments.AnimalsareHeterotrophicTheymustobtaincomplexorganicmaterialfromothersources..Mostaccomplishthisthroughingestion.Digestionisaccomplishedwithintheanimal.Thisprocessextractsthecarbohydrates,proteinandlipidsfromthefoodeaten.SexualReproductionandDevelopmentSexualreproductionrestoresthediploidnumberandincreasesgeneticvariation.Duringthedevelopmentalprocess,thezygoteundergoesmanymitoticdivisions.Theseidenticalcellsmustundergodifferentiation.Differentiationisprocessofcellbecomingdifferentfromeachotherandbeingspecialized.MovementMostanimalareabletomove.Theabilitytomoveresultsfromtheinterrelationsoftwotypesoftissuesfoundonlyinanimals:nervoustissueandmusculartissue.Thereareafewanimalsthataresessile.OriginandClassificationThefirstanimalsprobablyarosefromthesea..Taxonomistshavegroupedanimalsintoseveralphylabasedonevolutionaryrelationships..Manytaxonomistrecognize30ormoreanimalphyla.Wewillinvestigate11phyla.TenofthephylaincludeinvertebratesandonlyChordataincludesthevertebrates.AnimalBodyStructureSymmetryGermlayersBodyCavitiesSymmetryAsymmetryreferstotheconsistentoverallpatternofstructureofananimal.Animalshavethreepatternsofsymmetry..Asymmetry––nosymmetryRadialSymmetry––similarpartsbranchinalldirectionsfromacentralpointBilateralSymmetry--similarhalvesoneithersideofacentralplane.PatternsofSymmetryIdentifytheTypeofSymmetryMostanimalshaveadorsal,ventral,anteriorandposteriorsideororientation.Dorsal––topVentral–bottomAnterior––headPosterior--tailMostanimalsexhibitcephalization,theconcentrationofsensoryandbrainstructuresintheanterior.Animalswithcephalizationhaveahead!GermLayersGermlayersarefundamentaltissuetypesfoundinallanimalsexceptsponges(notruetissues)).EctodermMesodermEndodermBodyCavitiesMostanimalshaveafluidfilledspacethatformsbetweenthedigestivetractandtheouterwallofthebodyduringdevelopment.ThisspaceisknownasaCOELOM.Acoelomate(withoutacoelom)2germlayersectodermandendodermnotseparatedbyacavityleastcomplexbodyplanspongesandcnidarians3layeracoelomate3germlayersendoderm,mesodermandectodermnotseparatedbyacavityflatwormsPseudocoelomatepseudocoelomcavityformedbetweenmesodermandendodermroundwormsandrotifersCoelomatecavitydevelopedwithinthemesodermmostcomplexbodyplanmollusks,annelids,,arthropods,,echinoderms,andchordatesAnimalDiversityInvertebrates10phyla95%ofanimalsChordatesNotochordDorsalnervecordPharyngealpouchesPostanaltailVertebratesIncludefishes,birdsandmammalsKingdomAnimaliaInvertebratesChordatesVertebratesWhatisthedifferenceinavertebrateand