1. Chapter 10 CLASSIFICATION Classification: an orderly grouping of organisms The study of classifying organisms is called taxonomy –Provides universal names for organisms –Provides a reference for identifying organisms There are tow approaches to classification

2. Convenience vs. Phylogenetic Classification THE CLASSIFICATION SCHEMES IN PLACE TODAY ARE MAINLY BASED ON THE CONVENIENCE METHOD. ANY PHYLOGENY IS ASSUMED AND NOT PROVED SCIENTIFICALLY.

3. History of Kingdom WHITTAKER’S FIVE KINGDOM CLASSIFICATION - A CONVENIENCE METHOD. THE HISTORY OF KINGDOM CLASSIFICATION SCHEMES THE FIRST CLASSIFICATION SCHEME WAS DEVELOPED BY ARISTOTLE 2000 YEARS AGO. PLANTS AND ANIMALS.

4. History of Kingdom (continue) IN THE LATE 1800’S, A THIRD KINGDOM WAS ADDED: PROTISTA IN THE 1950’S, A FORTH KINGDOM WAS ADDED: MONERA PROCARYOTIC AND EUCARYOTIC CELL STRUCTURE

7. History of Kingdom IN 1969, A FIFTH KINGDOM WAS ADDED: FUNGI

8. Taxonomy 1735Plant and Animal Kingdoms 1857Bacteria & fungi put in the Plant Kingdom 1866Kingdom Protista proposed for bacteria, protozoa, algae, & fungi 1937"Prokaryote" introduced for cells "without a nucleus" 1961Prokaryote defined as cells in which nucleoplasm is not surrounded by a nuclear membrane 1959Kingdom Fungi 1968Kingdom Prokaryotae proposed 1978Two types of prokaryotic cells found

9. The Basis of Five Kingdom WHITTAKER’S FIVE KIGNDOM CLASSIFICATION RELATED ALL ORGANISMS ON THE BASIS OF: 1. MODES OF NUTRITION 2. POSITION IN THE ECOLOGICAL FOOD CHAIN A. PRODUCER B. CONSUMER C. DECOMPOSER

10. The Basis of Five Kingdom (continue) 3. CELLULAR ORGANIZATION A. SINGLE CELL B. MULTICELLULAR C. PROCARYOTIC/EUCARYOTIC 4. EVOLUTIONARY TREND WITHIN THE INDIVIDUAL KINGDOMS, ORGANISMS ARE FURTHER GROUPED INTO SMALLER GROUPS AS FOLLOWS:

11. The Basis of Five Kingdom (continue) PHYLUM/DIVISION CLASS ORDER FAMILY GENUS SPECIES STRAIN/VARIANT/SUBSPESCIES

13. THE PHYLOGENETIC APPROACH ORGANISMS THAT ARE GENETICALLY RELATED WILL HAVE MORE CHARACTERISTICS IN COMMON THAN ORGANISMS THAT LOOK A LIKE. CARL WOESE AND FRIENDS HAVE BEEN WORKING SINCE 1970 TO PUT IN PLACE A PHYLOGENETIC CLASSIFICATION SCHEME.

14. THE PHYLOGENETIC APPROACH (continue) COMPARE HEREDITARY MOLECULES OF ORGANISMS. THEY SELECTED RIBOSOMAL RNA BECAUSE: ALL CELLS HAVE IT AND PLENTY OF IT. ITS FUNCTION IS THE SAME IN ALL CELLS. ITS NITROGEN BASE SEQUENCE IS MODERATELY CONSERVED FROM GENERATION TO GENERATION.

15. THE PHYLOGENETIC APPROACH (continue) WOESE SEPARATED ORGANISMS IN THE MONERA INTO TWO GROUPS: - ARCHAEABACTERIA - EUBACTERIA ARCHAEABCTERIA TEND TO THRIVE IN EXTREME ENVIRONMENTS, EUBACTERIA DO NOT. ALSO, THERE ARE STRUCTURAL DIFFERENCES BETWEEN THESE TWO GROUPS OF BACTERIA.

16. The Three-Domain System