17.4 Domains and Kingdoms KEY CONCEPT The current tree of life has three domains. 17.4 Domains and Kingdoms Classification is always a work in progress. • The tree of life shows our most current understanding. • New discoveries can lead to changes in classification. 17.4 Domains and Kingdoms The three domains in the tree of life are Bacteria, Archaea, and Eukarya. • Domains are above the kingdom level. – proposed by Carl Woese based on rRNA studies of prokaryotes – domain model more clearly shows prokaryotic diversity 17.4 Domains and Kingdoms • Domain Bacteria includes prokaryotes in the kingdom Bacteria. – one of largest groups on Earth – classified by shape, need for oxygen, and diseases caused – The kingdom bacteria includes single celled prokaryotes 17.4 Domains and Kingdoms • Domain Archaea includes prokaryotes in the kingdom Archaea. – cell walls chemically different from bacteria – differences discovered by studying RNA – known for living in extreme environments 17.4 Domains and Kingdoms • Domain Eukarya includes all eukaryotes. – Kingdom Protista – can be heterotrophic or autotrophic – most live in water (though some live in moist soil or even the human body) – A protist is any organism that is not a plant, animal or fungus 17.4 Domains and Kingdoms • Domain Eukarya includes all eukaryotes. – Kingdom Plantae – all land plants: mosses, ferns, conifers, flowering plants, and such 17.4 Domains and Kingdoms • Domain Eukarya includes all eukaryotes. – – – – Kingdom Fungi Eukaryotic Heterotrophic Instead of ingest then digest – they digest then ingest – Recent studies suggest they are more closely related to animals than plants. 17.4 Domains and Kingdoms • Domain Eukarya includes all eukaryotes. – Kingdom Animalia 17.4 Domains and Kingdoms Bell Ringer: • Interpret this quote…(5 sentences!!!) “If a man is called to be a streetsweeper, he should sweep streets even as Michelangelo painted, or Beethoven composed music, or Shakespeare wrote poetry. He should sweep streets so well that all the hosts of heaven and Earth will pause to say, Here lived a great streetsweeper who did his job well.” -Martin Luther King 17.4 Domains and Kingdoms KEY CONCEPT The current tree of life has three domains.