1_GBIntroductionPart1

LectureOutlinesbyGregoryAhearn,UniversityofNorthFloridaChapter1AnIntroductionToLifeOnEarthCopyright©2011PearsonEducationInc.Biology:LifeonEarth,9eGoalsoflearningAnavigationallearningofwhatislife,andwhatislifescience.(Trynottothinkthecontentsaretoosimple!)Developacohesiveknowledgeofthecharacteristicsoflivingthings,whichwouldenablepeopletodiscovernewcodes---logicsoflife.Fosteringanattitudeofinquiryandappreciationoftheknowledgegainedthroughscience.Tobeinspiredaboutlifescience,studentsmustappreciatethatlifescienceisaboutourownbody-howitworks,andmaintainshealth,etc.Copyright©2011PearsonEducationInc.Biology:LifeonEarth,9eHowtostudyTheflowwillbebasedontheassignedtextbook.EmphasiswillbecoveredinlecturePowerPointslides.Toperformwell,studentsareadvisedtoreadtheentirechaptersandrevisethoroughlyovertheslides.Copyright©2011PearsonEducationInc.Biology:LifeonEarth,9eChapter11.1Whatarethecharacteristicsoflivingthings?1.2Howdoscientistsstudylife?1.3Howdoscientistscategorizethediversityoflife?Copyright©2011PearsonEducationInc.Biology:LifeonEarth,9eDefininglifeThedictionarydefinitionoflifeis“thequalitythatdistinguishesavitalandfunctioningbeingfromadeadbody”.Livingthingsaremorethanthesumoftheirparts;livingorganismsarenotamerecollectionofinanimatematerials.Thecomplexityandorderedinteractionsofpartsinlivingthingsgiverisetocertainproperties.Whatislife?Copyright©2011PearsonEducationInc.Biology:LifeonEarth,9eOrganismsarecomplex,organized,andcomposedofcellsOrganismsacquireandusematerialsandenergyOrganismsmaintainrelativelyconstantinternalconditionsthroughhomeostasisOrganismsperceiveandrespondtostimuliOrganismsgrowandreproduceOrganismscanevolve1.1Whatarethecharacteristicsoflivingthings?Copyright©2011PearsonEducationInc.Biology:LifeonEarth,9eOrganizationLivingthingsarecomposedofcells(continued)Allcellscontain:GenesthatprovideinformationtocontrolthelifeofthecellOrganelles,whicharesmall,specializedstructuresthatperformspecificfunctionsAplasmamembranethatenclosesthefluidcytoplasmandorganellesfromtheoutsideworldCopyright©2011PearsonEducationInc.Biology:LifeonEarth,9eLivingthingsarecomposedofcellsLivingthingsarebothcomplexandorganizedCopyright©2011PearsonEducationInc.Biology:LifeonEarth,9eatomsmoleculesOrganelles/cellstissuesorganssystemsorganismsorganizedcomplexityCopyright©2011PearsonEducationInc.Biology:LifeonEarth,9eUseofmaterialsLivingthingsacquirematerials(continued)Importantmaterials(nutrients)areacquiredfromair,water,soil,orotherlivingthingsNutrientsareincorporatedintothebodiesoforganismsNutrientsarecontinuouslyrecycledamonglivingandnonlivingthingsCopyright©2011PearsonEducationInc.Biology:LifeonEarth,9eAcquisitionofenergyLivingthingsobtainenergyintwowaysPlantsandsomesingle-celledorganismscapturesunlightinphotosynthesisOtherorganismsconsumeenergy-richmoleculesinthebodiesofotherorganismsAllenergythatsustainslifecomesdirectlyorindirectlyfromthesunCopyright©2011PearsonEducationInc.Biology:LifeonEarth,9eOrganismsuseenergy1.buildpartsofcells2.movearound(work)3.generateheat4.maintainhomeostasis5.grow,develop,andreproduce•LivingthingsacquirematerialsMaterialsandenergyarerequiredfortheorganismtomaintainorganization,togrow,andtoreproduceCopyright©2011PearsonEducationInc.Biology:LifeonEarth,9eOrganismsabsorbenergyCopyright©2011PearsonEducationInc.Biology:LifeonEarth,9eTheFlowofEnergyandtheRecyclingofNutrientsCopyright©2011PearsonEducationInc.Biology:LifeonEarth,9eHomeostasisOrganismsmustmaintainrelativelyconstantinternalconditions,orhomeostasisbodytemperature,energylevelHomeostaticmechanismsinclude:SweatinginhotweatherordousingoneselfwithcoolwaterMetabolizingmorefood,baskinginthesun,orturningupthethermostatincoldweatherWhenAMP/ATPisincreased,cellsincreasecatabolic(分解)processes(fattyacidoxidation),whiledecreasinganabolic（合成）rates(suchasfatsynthesis)Organismsmaintainhomeostasis(稳态)Copyright©2011PearsonEducationInc.Biology:LifeonEarth,9eLivingthingsrespondtostimuliOrganismssenseandrespondtointernalandexternalenvironmentalstimuli（刺激物，信号）Sensoryorgansinanimalscandetectandrespondtoexternalstimulilikelight,sound,chemicals,etc.Internalstimuliinanimalsareperceivedbystretch(伸展),temperature,pain,andchemicalreceptorsPlantsandbacteriarespondtostimuliaswell(e.g.,plantsgrowtowardthelight,andbacteriamovetowardavailablenutrientsinamedium)Copyright©2011PearsonEducationInc.Biology:LifeonEarth,9eOrganismsrespondtostimuliSunlight,chemicals,hormones,heat,touchIlovethislightsunWhenindangerPhototaxis:趋光性glucoseInsulin•CellsdependonexternalfactorsfornutrientuptakeCopyright©2011PearsonEducationInc.Biology:LifeonEarth,9eGrowthLivingthingsgrowEveryorganismbecomeslargerovertimePlants,birds,andmammalsgrowbyproducingmorecellstoincreasetheirmassBacteriagrowbyenlargingtheircells;theyalsodividetomakemoreindividualsGrowthinvolvestheconversionofacquiredmaterialstomoleculesoftheorganism’sbodyCopyright©2011PearsonEducationInc.Biology:LifeonEarth,9eLivingthingsreproducethemselvesOrganismsgiverisetooffspringofthesametypeThepare