C2 - Taxonomy Flashcards
area of biologic science comprising three distinct but highly interrelated disciplines
Taxonomy
What are the three distinct but highly interrelated disciplines associated with taxonomy?
- Classification
- nomenclature
- identification of organisms
→ orderly classification and grouping of organisms into taxa (categories)
→based on similarities and differences in genotype and phenotype
Taxonomy
laid down the basic rules for taxonomic categories
Carl von Linne
it is the method for organizing microorganisms into groups or taxa based on similar morphologic, physiologic, and genetic traits
classification
(classification) Bacteria and Archaebacteria
Domain
(classification) contains similar divisions or phyla
Kingdom
(classification) contains similar classes; equivalent to the Division taxa
Phylum
(classification) contains similar orders
Class
(classification) contains similar families
Order
(classification) contains similar genera
Family
(classification) contains similar species based on various genetic and phenotypic characteristics shared among the species
Genus
(classification) specific epithet; most basic of the taxonomic groups and can be defined as a collection of bacterial strains that share common physiologic and genetic features and differ notably from other microbial species
Species
(classification) taxonomic subgroups within a species
Subspecies
(classification) considered the same species with the same characteristic genetic makeup that displays differential physiologic characteristics
Biotype
(classification) based on serologic differences
Serotype
Species definitions are distinguished using:
DNA profiling, 16S rRNA sequence in combination with phenotypic traits
naming of microorganisms according to established rules and guidelines set forth in the:
International Code of Nomenclature of Bacteria/ Bacteriological Code
→ Process by which a microorganism’s key features are delineated
→ Process of discovering and recording the traits of organisms so that they may be placed in an overall taxonomic scheme
identification
(characteristics) relate to an organism’s genetic makeup, including the nature of the organism’s genes and constituent nucleic acids
genotypic characteristics
(characteristics) example of genotypic method for measuring the degree of relatedness between two microorganisms
DNA RNA base sequencing, DNA base composition ratio
(characteristics) based on features beyond the genetic level and include both readily observable characteristics and characteristics that may require extensive analytic procedures to be detected
phenotypic characteristics
examples of phenotypic characteristics
macroscopic and microscopic morphology, staining characteristics, nutritional requirements, physiologic and biochemical characteristics, antibiotic/chemical susceptibility or resistance
(phenotypic characteristics) colony morphology on media
macroscopic
(phenotypic characteristics) size, shape, arrangement into groups or chains of organisms
microscopic
(phenotypic characteristics) gram-positive or gram-negative
staining characteristics
(phenotypic characteristics) ability of an organism to grow at various temperatures, i the presence of oxygen and other gases, at various pH levels, or in the presence of other ions and salts
environmental requirements
(phenotypic characteristics) ability of an organism to utilize various carbon and nitrogen sources as nutritional substrates when grown under specific environmental conditions
nutritional requirements
(phenotypic characteristics) exhibition of a characteristic inherent resistance to specific antibiotics, heavy metals, or toxins
resistance profiles
(phenotypic characteristics) establishment of profile of microorganisms by various serologic and immunologic methods
antigenic properties
(phenotypic characteristics) establishment of the molecular constituents if the cell that are typical of a particular taxon
subcellular properties
Major Characteristics Used in Taxonomy
classical, molecular characteristics
Major Characteristics Used in Taxonomy that is useful in routine identification of phylogenetic information
classical characteristics
Major Characteristics Used in Taxonomy Based on the study of nucleic acid composition and proteins
molecular characteristics
Organisms fall into three distinct groups based on type of cell organization and function:
bacteria, archaea, eukarya
closely related to eukaryotic cells than to prokaryotic cells; found in microorganisms that grow under extreme environmental conditions
archaebacteria
archaebacteria cell walls lack peptidoglycan but they mostly contain a protein or glycoprotein wall structure called:
S-layer
types of reproduction by archaebacteria
binary fission, fragmentation, budding
examples of archaebacteria produce through binary fission, fragmentation or budding
Methanospirillum, Halobacterium, Sulfolobus
→can stain gram-positive and gram-negative
→Cellular structure include the cell wall, plasma membrane, ribosomes and flagella
→Do not contain a nucleus and membrane-bound organelles
Archaea (Archaeobacteria)
Diagnostic microbiologists traditionally emphasize placement and naming of bacterial species into three (occasionally four or five) categories:
✓the family
✓a genus
✓a species
