2Species of Organisms There are 13 billion known species of organisms This is only 5% of all organisms that ever lived!!!!!New organisms are still being found and identified
3What is Classification? Classification is the arrangement of organisms into orderly groups based on their similaritiesClassification is also known as taxonomyTaxonomists are scientists that identify & name organisms
4Benefits of Classifying Accurately & uniformly names organismsPrevents misnomers such as starfish & jellyfish that aren't really fishUses same language (Latin or some Greek) for all namesSea”horse”??
13Rules for Naming Organisms The International Code for Binomial Nomenclature contains the rules for naming organismsAll names must be approved by International Naming Congresses (International Zoological Congress)This prevents duplicated names
14Classification Groups Taxon ( taxa-plural) is a category into which related organisms are placedThere is a hierarchy of groups (taxa) from broadest to most specificDomain, Kingdom, Phylum, Class, Order, Family, Genus, species
15Hierarchy-Taxonomic Groups DomainKingdomPhylum (Division – used for plants)ClassOrderFamilyGenusSpeciesBROADEST TAXONGenus and species are the two names used to identify specific organisms in the binomial system of classification. Division is used for plants.
18Domains Broadest, most inclusive taxon Three domains Archaea and Eubacteria are unicellular prokaryotes (no nucleus or membrane-bound organelles)Eukarya are more complex and have a nucleus and membrane-bound organelles
19Sewage treatment plants, thermal vents, etc. Archaea live in harsh environments and may represent the first cells to have evolved.Sewage treatment plants, thermal vents, etc.
20Many bacteria are important environmentally and commercially. Eubacteria, some of which cause human diseases, are present in almost all habitats on earth.Live in the intestines of animalsMany bacteria are important environmentally and commercially.
21Domain Eukarya is Divided into Kingdoms Protista (protozoans, algae…)Fungi (mushrooms, yeasts …)Plantae (multicellular plants)Animalia (multicellular animals)
22Protista Most are unicellular Some are multicellular Some are autotrophic, while others are heterotrophic
23Fungi Multicellular, except yeast Absorptive heterotrophs (digest food outside their body & then absorb it)Cell walls made of chitin
24Plantae Multicellular Autotrophic Absorb sunlight to make glucose – PhotosynthesisCell walls made of celluloseGrowth, with increases in size and number of cells, is part of development.Development involves many stages from conception until death.
25Animalia Multicellular Ingestive heterotrophs (consume food & digest it inside their bodies)Feed on plants or animals
35Dichotomous Keying Used to identify organisms Characteristics given in pairsRead both characteristics and either go to another set of characteristics OR identify the organism
36Example of Dichotomous Key 1a Tentacles present – Go to 21b Tentacles absent – Go to 32a Eight Tentacles – Octopus2b More than 8 tentacles – 33a Tentacles hang down – go to 43b Tentacles upright–Sea Anemone4a Balloon-shaped body–Jellyfish4b Body NOT balloon-shaped - 5