2 Classification- putting things into groups based on shared characteristics There have been many different ideas about how to classify living things.Aristotle placed all organisms into 2 large groups-plants and animals
3 Linnaeus’ System Linnaeus founded modern taxonomy. Taxonomy- the science of describing , classifying , and naming living thingsBased on 7 hierarchical categoriesSimplified the naming of living things by giving each species a two-part specific name “Binomial nomenclature”
4 Binomial Nomenclature GenusSpeciesFelis domesticusIn a scientific name, the first part of the name is the organism’s genus. Similar species are grouped into one genus. Ex: FelisThe second part of the name identifies the species- a group of organisms that have similar traits and are able to produce fertile offspring.
5 Binomial Nomenclature Panthera tigrisPanthera leo
6 Classification TodayTaxonomists use an eight-level system to classify living things based on shared characteristics.The more characteristics the organisms share, the more closely related the organisms may be.
7 Levels Of Classification DomainKingdomPhylumClassOrderFamilyGenusSpecies
9 DOMAINS Every living thing is classified into one of the 3 Domains: ArcheaBacteriaEukarya
10 DOMAIN 1: ARCHAEA ARCHAEBACTERIA Unicellular prokaryotes Often live in harsh environmentssome produce food by chemosynthesis (energy obtained from places other than the sun)
11 DOMAIN 2: BACTERIA Unicellular prokaryotes Have a Cell wall and membraneMost abundant organisms
12 DOMAIN 3: EUKARYA EUKARYOTES Complex cells; nuclei and organelles in cellsSome are unicellularSome are multicellularThe domain Eukarya is divided into 4 Kingdoms:ProtistaFungiPlantaeAnimalia
13 Eukarya: ProtistaOne celled or Multicellular organisms that can either be plant-like, animal like, or bothAlgae, Amoebas, Paramecium , Euglena
14 Eukarya: Fungi Multicellular Cell wall Does not perform photosynthesis Absorbs nutrientsReproduce using spores.
15 Eukarya: Plantae Cell wall Perform photosynthesis Vascular vs. nonvascularFlowering vs. nonflowering
16 Eukarya: Animalia Multi-cellular organisms that lack cell walls Range from simple to complexInvertebrates- Do not have a backboneWormsSpongesJelly FishMollusksInsectsVertebrates – Have a backboneFishAmphibiansReptilesBirdsMammals
19 Dichotomous KeyA series of descriptions arranged in pairs that can be used to identify an unknown organismThe chosen descriptions leads to another pair of descriptions or to the identification of the organism