Module 1 Flashcards
Taxonomy
Science of classification
Classification
Arrangement of organisms into taxonomic groups on the basis of similarities
Nomenclature
Assignment of names
Identification
Determining which taxonomic group a new isolate belongs
Eucaryotic
eu=true caryotic=nucleus
organized nucleus with several chromosomes
nuclear membrane present
Procaryotic
pro=primitive
lack of organized nucleus
one singular chromosome
no nuclear membrane
Kingdom History
1700s Carlos Linnaeus made Plantae(bacteria) and Animalis
1866 Ernst Haeckel made Protista for all microorganisms
Current Kingdom
Procaryotae (AKA Monera) for all bacteria
Lab “Bible”
Bergeys Manual of Determinative Bacteriology
Large to small Kingdoms and groups
Kingdom - Procaryote Division/phylum - 4 divisions Class - 1-3 classes per division Order - Several orders per class Family - uses ending -aceae Tribe - Only used with large number of bacteria in one family (uses ending -eae) Genus Species (King David Came Over For The Great Spaghetti)
Species
Population of cells with similar characteristics
Type Strain
permanent example of the species or reference specimen for that name
Subspecies
Official taxonomic group, smaller than species, with minor but consistent differences than the type species
Biotype (Biovar)
Type of subspecies distinguishable by biochemical or physiological properties that differ from the type strain
Serotype (Serovar)
Type of subspecies distinguishable by distinctive antigenic or serological properties that differ from the type strain
Proper Nomenclature
Includes a genus name followed by a species name
Genus name is Capitalized (typically end is -us, -um, -a)
Species is not capitalized
Full nomenclature is typed in italics or written with an underline.
Classification Methods (4)
Key system
Base Composition of Nucleic Acid
Nucleic Acid Hybridization
Numerical Taxonomy
Key System
Bacterial shapes and gram stain were heavily weighted
Bacteria were placed into groups that were often genetically unrelated
Base Composition of Nucleic Acid
Base composition determines percentage guanine-cytosine (G+C) in nucleic acid
Bacteria with the same composition percentage are of the same species*
Close percentages=close species
*BUT, the same G+C% does not always mean the same species - they could be made from a different sequence
Nucleic Acid Hybridization
DS DNA separated into single strands when heated, if strands from different organisms are combined and they successfully hybridize when cooled, they are the same. Degree of hybridization determines how closely related the 2 organisms are.
Numerical Taxonomy
Characteristics weighted equally (ex. morphological, biochemical properties)
computer matches characteristics
>90% match indicates the same type of organism
