Life The Science of Biology, 9e.ppt

studyinglife 1studyinglife 1 1whatisbiology 1 2howisalllifeonearthrelated 1 3howdobiologistsinvestigatelife 1 4howdoesbiologyinfluencepublicpolicy 1 1whatisbiology biology thescientificstudyoflivingthings livingthings alltheorganismsdescendedfromasingle celledancestor 1 1whatisbiology characteristicsoflivingorganisms consistofoneormorecells livingcelltheory containgeneticinformation dna usegeneticinformationtoreproducethemselves replicate aregeneticallyrelatedandhaveevolvedcanconvertmoleculesfromtheirenvironmentintonewbiologicalmolecules metabolism extractenergyfromtheenvironmentanduseittodobiologicalwork metabolism regulatetheirinternalenvironment homeostasis 1 1whatisbiology evolution acentralthemeofbiology butwewon tcoverinthisclass butitcanbesummarizeasfollow livingsystemsevolvethroughdifferentialsurvivalandreproduction theprocessesofevolutionhavegeneratedtheenormousdiversityoflifeonearth 1 1whatisbiology consistofoneormorecells livingcelltheory unicellularorganisms asinglecellcarriesoutallthefunctionsoflife multicellularorganisms madeofmanycellsthatarespecializedfordifferentfunctions biology thescientificstudyoflivingthings livingthings alltheorganismsdescendedfromasingle celledancestor 1 1whatisbiology consistofoneormorecells livingcelltheory thestudyofcellswasmadepossiblebytheinventionofmicroscopes tomorrow slab roberthookeinthe1600sdescribedrepeatingunitsofplantmaterialascells 1 1whatisbiology celltheory schleidenandschwann1838 cellsarethebasicstructuralandphysiologicalunitsofalllivingorganisms cellsarebothdistinctentitiesandbuildingblocksofmorecomplexorganisms allcellscomefrompreexistingcells allcellsaresimilarinchemicalcomposition mostofthechemicalreactionsoflifeoccurwithincells completesetsofgeneticinformationarereplicatedandpassedonduringcelldivision 1 1whatisbiology evolution changeinthegeneticmakeupofbiologicalpopulationsthroughtime charlesdarwinproposedthatalllivingorganismsaredescendedfromacommonancestorbythemechanismofnaturalselection humansselectfordesiredtraitswhenbreedinganimals darwinpostulatedthatnaturalselectioncouldoccurthroughdifferentialsurvivalandreproductivesuccess traitsthatincreasetheprobabilitythattheorganismwillsurviveandreproducewillbecomemorecommoninthepopulation naturalselectionandotherevolutionaryprocesses e g sexualselectionandgeneticdrift leadtoadaptation 1 1whatisbiology containgeneticinformation dna genome sumtotalofallthednainacell dna theinformationthatispassedfromparenttodaughtercells allcellsinamulticellularorganismhavethesamegenome dnaconsistsofrepeatingsubunitscallednucleotides gene aspecificsegmentofdnathatcontainsinformationformakingaprotein mutationsarealterationsinthenucleotidesequence 1 1whatisbiology metabolism organismsacquirenutrientsfromtheirenvironment nutrientssupplyenergyandmaterialsforbiochemicalreactions somereactionsbreaknutrientmoleculesintosmallerunits releasingenergyforwork examplesofcellularwork movementofmolecules orthewholeorganismsynthesis buildingnewcomplexmoleculesfromsmallerchemicalunitselectricalworkofinformationprocessinginnervoussystems 1 1whatisbiology metabolism singlecell metabolism ormetabolicrate thesumtotalofallchemicaltransformationsandotherworkdoneinallthecellsofanorganism thereactionsareintegrallylinked theproductsofonearetherawmaterialsofthenext 1 1whatisbiology metabolism multicellular multicellularorganismshaveaninternalenvironmentthatisnotcellular theircellsarespecializedordifferentiated andorganizedintotissues tissuesareorganizedintoorgans organsystemsaregroupsoforganswithinterrelatedfunctions 1 1whatisbiology livingorganismsalsointeract populationsaregroupsofindividualsofthesamespeciesthatinteractwithoneanother acommunityconsistsofpopulationsofallthespeciesthatliveinthesameareaandinteract communitiesplustheirabioticenvironmentconstituteanecosystem figure1 6biologyisstudiedatmanylevelsoforganization part1 1 1whatisbiology individualsmaycompetewitheachotherforresources ortheymaycooperate e g inatermitecolony plantsalsocompeteforlightandwater andmanyformcomplexpartnershipswithfungi bacteria andanimals theinteractionsofplantandanimalspeciesaremajorevolutionaryforcesthatproducespecializedadaptations speciesinteractionswithoneanotherandwiththeirenvironmentisthesubjectofecology 1 2howisalllifeonearthrelated lifearosefromnonlifeabout3 8billionyearsagowheninteractingsystemsofmoleculesbecameenclosedinmembranestoformcells 1 2howisalllifeonearthrelated lifearosebychemicalevolution moleculesthatcouldreproducethemselveswerecritical biologicalmoleculeswerethenenclosedinmembranes formingcells for2billionyears lifeconsistedofsinglecellscalledprokaryotes thesecellswereintheoceans protectedfromuvradiation therewaslittleornooxygen o2 intheatmosphere andhencenoprotectiveozone o3 layer 1 2howisalllifeonearthrelated photosynthesisevolvedabout2 5billionyearsago thisprocesstransformssunlightenergyintobiologicalenergy earlyphotosyntheticcellswereprobablysimilartocyanobacteria 1 2howisalllifeonearthrelated consequencesofphotosynthesis o2accumulatedintheatmosphereaerobicmetabolismbegan ozonelayerformed whichallowedorganismstoliveonland eukaryoticcellsevolvedfromprokaryotes thesecellshaveintracellularcompartmentscalledorganelleswithspecializedcellularfunctions thenucleuscontainsthegeneticinformation 1 2howisalllifeonearthrelated someorganellesprobablyoriginatedbyendosymbiosis whencellsingestedsmallercells mitochondria generatecell senergy andchloroplasts conductphotosynthesis couldhaveoriginatedwhenprokaryoteswereingestedbylargereukaryotes multicellularorganismsaroseabout1billionyearsago cellularspecialization cellsbecamespecializedtoperformcertainfunctions 1 3howdobiologistsinvestigatelife biologistsusemanymethodstoexpandourunderstandingoflife observation improvedbynewtechnologiesexperimentation 1 3howdobiologistsinvestigatelife observationsquestionsh