1. Classification and Nomenclature Chap 3 1

2. Classification Systems: Taxonomy 2

3. Early Classification Systems Carolus Linnaeus (1750s) – Established a uniform naming system based on shared characteristics – Two Kingdom System 1.Plant 2.Animal – Binomial nomenclature 3

4. Early Classification Systems Ernst Haeckel—1860s – Too many characteristics not accounted for in Linnaeus’ system – Three Kingdom System 1.Plant 2.Animal 3.Protista  Prokaryote – No nucleus (“pro” – before)  Eukaryote – Nucleus (“eu” – true) 4

5. Modern Classification Systems Robert Whittaker (1969) – Five-Kingdom System 1.Monera - bacteria 2.Protista – unicellular algae & protozoa 3.Fungi – molds, yeasts & mushrooms 4.Plantae – plants, mosses & multicellular algae 5.Animalia – worms to vertebrates 5

6. The Five-Kingdom System 6 Fig 3.6 Still based primarily on external characteristics

7. Five-Kingdom System Breakout Kingdom Phylum Class Order Family Genus Species 7 Knowing Phil can often find good surf.

8. Modern Classifications Systems Carl Woese (late 1970s) >> Classification based on rRNA, sensitivity to antibiotics and lipid structure of the membrane – Three-domain system 1.Archea 2.Eubacteria 3.Eukarya – Domain grouping does not override the KPCOFGS taxonomic groupings 8 Prokaryotes Eukaryotes

9. The Three-Domain System 9 Classification based on rRNA, sensitivity to antibiotics and lipid structure of the membrane Fig 3.7

10. Wider Acceptance of Three-Domain System Craig Venter (1996) – Celera Genomics Sequenced the human genome – Showed that a species of archeabacteria was very different from bacteria 10 http://student.ccbcmd.edu/courses/bio141/lecguide/unit1/3domain/3domain.html

11. Classifying Prokaryotes- Bacterial Taxonomy Bergey’s Manual (1924) – Criteria for classification and identification Morphology and other physical characteristics Growth in culture Metabolism Antigenicity Genetics Pathogenicity Ecology 11

12. Bacterial Taxonomy Morphology – Cell size – Cell shape and arrangement – Staining reactions Indicates chemical components of cell walls 12

13. Bacterial Taxonomy Growth in culture – Temperature, gas, light, nutrient requirements – Living host?

14. Bacterial Taxonomy Metabolism – Fermentation of carbohydrates – Utilization of specific substrates Determines if specific enzymes are present – Production of specific products or waste products 14

15. Bacterial Taxonomy Antigenicity – Serological test determine the immune response elicited by the microorganism

16. Bacterial Taxonomy Pathogenicity – Causes disease? – Host – plant or animal? Ecology – Habitat Thermophile Halophile 16

17. Bacterial Taxonomy Genetics – RNA or DNA – Check the G-C ratio – Plasmids This becomes very important very quickly in the scientific world

18. Molecular Taxonomy Basis for the three-domain system of classification Based on the presence of ribosomes in all living organisms Will become more complex as techniques evolve 18

19. Nomenclature 19 http://student.ccbcmd.edu/courses/bio141/lecguide/unit1/3domain/3domain.html

20. Accepted Nomenclature Binomial system that identifies each organism by a universally-accepted scientific name First word – Genus Second word – Species 20

21. Accepted Nomenclature Genus sometimes from – Latin root: Bacillus – “small rod” – Greek root: Clostrdium – “small spindle” – People: Escherichia – Theodore Escherich who isolated the cells in 1895 21

22. Accepted Nomenclature Species names – Albus - white – Aureus - gold – Lutea – yellow – Meningitidis – inflammation of the meningies 22

23. Proper Written Form Genus is Capitalized and italicized – May be abbreviated Species is lower case and italicized Ex. Bacillus subtilis B. subtilis 23

24. 24 Unknown Bacterium PositiveNegative Positive Negative PositiveNegative Citrobacter Escherichia Citrobacter Enterobacter intermedius coli freudii aerogenes Gram Stain Lactose fermentation Indole production Use of citrate as sole carbon source Methyl red reaction MicroFocus 3.4 pg 85 – Dichotomous Key