17 4 Domains and Kingdoms KEY CONCEPT The

17. 4 Domains and Kingdoms KEY CONCEPT The current Tree of Life has Three domains and Six Kingdoms.

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. – From 1753 -1866: Linnaeus created only two kingdoms, Animalia and Plantae Animalia

17. 4 Domains and Kingdoms Classification is always a work in progress. – Until 1866: only two kingdoms, Animalia and Plantae Animalia Protista *1866: all single-celled organisms moved to kingdom Protista

17. 4 Domains and Kingdoms Classification is always a work in progress. – Until 1866: only two kingdoms, Animalia and Plantae Animalia Protista – 1866: all single-celled organisms moved to Kingdom Protista *1938: prokaryotes moved to Kingdom Monera

17. 4 Domains and Kingdoms Classification is always a work in progress. • New discoveries can lead to changes in classification. – Until 1866: only two kingdoms, Animalia and Plantae Animalia Protista – 1866: all single-celled organisms moved to Kingdom Protista – 1938: prokaryotes moved to Kingdom Monera *1959: Fungi moved to own kingdom Plantae Monera Fungi

17. 4 Domains and Kingdoms Classification is always a work in progress. – Until 1866: only two kingdoms, Animalia and Plantae – 1866: all single-celled organisms moved to Kingdom Protista Plantae Animalia Protista – 1938: prokaryotes moved to Kingdom Monera – 1959: fungi moved to own kingdom Fungi *1977: Kingdom Monera split into Kingdoms Bacteria and Archaea Archea Bacteria

17. 4 Domains and Kingdoms The three domains in the tree of life are Bacteria, Archaea, and Eukarya. • Domains are above the kingdom level. (Larger category) – proposed by Carl Woese based on r. RNA 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 ex. Strep, E. coli, staph infection, food poisoning

17. 4 Domains and Kingdoms • Domain Archaea includes prokaryotes in the Kingdom Archaea. Ex. Halophiles , thermophiles – cell walls chemically different from bacteria -Peptidoglycan – differences discovered by studying RNA – known for living in extreme environments (hot, salty)

17. 4 Domains and Kingdoms • Domain Eukarya includes all eukaryotes. 1. Kingdom Protista (seaweed, diatoms, amoeba…)

17. 4 Domains and Kingdoms • Domain Eukarya includes all eukaryotes. 4 Kingdoms 2. Kingdom Plantae (mosses, ferns, conifers, flowering plants…)

17. 4 Domains and Kingdoms • Domain Eukarya includes all eukaryotes. 3. Kingdom Fungi (mushroom, athlete’s foot, mold, yeast…)

17. 4 Domains and Kingdoms • Domain Eukarya includes all eukaryotes. 4. Kingdom Animalia (sponges, jellyfish, roundworms, segmented worms, flatworms, echinoderms, mollusks, arthropods, Chordates – spinal cord such as reptiles, fishes, mammals, amphibians, birds)

17. 4 Domains and Kingdoms • Bacteria and archaea can be difficult to classify. – transfer genes among themselves outside of reproduction bridge to transfer DNA – blurs the line between “species” – more research needed to understand prokaryotes

17. 4 Domains and Kingdoms Section 18 -3 Figure 18 -12 Key Characteristics of Kingdoms and Domain DOMAIN KINGDOM CELL TYPE CELL STRUCTURES Bacteria Archaea Bacteria Archaebacteria EXAMPLES Protista Fungi Plantae Animalia Prokaryote Eukaryote Cell walls with peptidoglycan Cell walls without peptidoglycan Cell walls of cellulose in some; some have chloroplasts Cell walls of chitin Cell walls of cellulose; chloroplasts No cell walls or chloroplasts Unicellular Most unicellular; some colonial; some multicellular Most multicellular; some unicellular Multicellular Autotroph or heterotroph Heterotroph Autotroph Heterotroph Streptococcus, Escherichia coli Methanogens, halophiles Amoeba, Paramecium, slime molds, giant kelp Mushrooms, yeasts Mosses, ferns, flowering plants Sponges, worms, insects, fishes, mammals NUMBER OF CELLS MODE OF NUTRITION Eukarya