1. 18-3 Kingdoms and Domains

2. The Tree of Life Evolves  Organisms originally grouped as either plant or animal  Scientists realized that bacteria, protists and fungi were quite different from plant and animal groupings

3. Tree of Life Evolves  Bacteria and protists were placed in the kingdom Protista  Fungus, yeasts and molds placed in kingdom Fungi

4. Tree of Life Evolves  Realized bacteria lacked nuclei and organelles  Regrouped into kingdom Monera

5. Tree of Life Evolves  This process lead to 5 kingdoms: –Monera –Protista –Fungi –Plantae –Animalia

6. Tree of Life Evolves  In recent years, it has been discovered that bacteria fit into 2 distinct categories  Monera has been broken into: –Archaebacteria (ancient bacteria) –Eubacteria (new bacteria

7. The Three Domain System  Domain is a more inclusive category than kingdom  Three domains: –Eukarya: includes protists, fungi, plants, and animals –Bacteria: includes kingdom Eubacteria –Archaea: includes kingdom Archaebacteria

8. Domain Bacteria  Members of domain bacteria are unicellular and prokaryotic  Have thick, rigid cell walls around cell membrane  Cell wall contains peptidoglycan

9. Domain Bacteria  Ecologically diverse – free-living soil organisms to deadly parasites  Some photosynthesize others don’t  Some need oxygen, others killed by it

10. Domain Archaea  Unicellular and prokaryotic  Live in most extreme environments –Hot springs, brine pools, and black organic mud  Many only live in anaerobic environments  Cell walls lack peptidoglycan

11. Domain Eukarya  Consists of all organisms that have a nucleus  Composed of kingdoms: –Protista –Fungi –Plantae –Animalia

12. Protista  Eukaryotic organisms that can’t be classified as plant, animal, or fungi  Members have great variety  Most are single-celled, multicellular algae

13. Protista  Photosynthetic or heterotrophic  Some have characteristics of fungi –Others characteristics of plants –Others characteristics of animals  Examples: amoeba, paramecium

14. Fungi  Heterotrophs  Feed on dead or decaying organic matter  Secrete digestive enzymes into food, and absorb molecules through bodies  Multicellular (mushrooms) and unicellular (yeasts)

15. Plantae  Multicellular  Photosynthetic autotrophs  Nonmotile (don’t move)  Cell walls that contain cellulose  Contains cone-bearing and flowering plants, mosses and ferns

16. Animalia  Multicellular and heterotrophic  Do not have cell walls  Most can move about for at least part of their life cycle  Great diversity, live in nearly every part of planet