Introduction to Taxonomy Differential Biology 6th Period April 11, 2005

Taxonomy Definition: The discipline of describing and classifying an organism.

7 levels of Taxonomy Kingdom Phylum Class Order Family Genus Species Philip Came Over For Green Spaghetti

5 Kingdoms Monera (bacteria) Protista Fungi Plantae Animalia

Cladograms These are organized according to shared, specialized characteristics. Example: In this sense birds are reptiles because the two groups have many similar derived characteristics.

Example of a Cladogram Source: http://www.amnh.org/exhibitions/hall_tour/spectrum/non_flash_index.html

Three Domains There is much debate about how many domains there should be and what they should include. Science has argued over this for years. For our class we will use the three most commonly accepted domains.

Three Domains Con’t Archaea – bacteria that lives in extreme habitats, possibly from primitive earth. Eubacteria – All other prokaryotic organisms. Eukarya – All eukaryotic life.

Comparison of Domains Characteristic Eubacteria ArchaeBacteria Eukaryotes Nuclear envelope absent present Organelles Peptidoglycan cell wall Type of membrane lipids Unbranched hydrocarbons Some branched hydrocarbons Source: http://www.cas.vanderbilt.edu/bsci100/bacteria.viruses.htm

Response to chloroamphenicol (antibiotic that inhibits protein Characteristic Eubacteria ArchaeBacteria Eukaryotes RNA polymerases One several Initiator amino acid formyl-methionine methionine Introns Absent present in some genes present Response to chloroamphenicol (antibiotic that inhibits protein synthesis) Sensitive insensitive Source: http://www.cas.vanderbilt.edu/bsci100/bacteria.viruses.htm

A Brief Summary What is taxonomy? What was the acronym for the 7 levels of taxa? Who can list the 7 levels? Why is there such a controversy over the domains?

Something To Look Forward To Tomorrow we are going to begin working on what is called a dichotomous key. It’s sort of like creating a map for identifying organisms.