Ch. 10: Classification of Microorganisms Flashcards
Taxonomy
The science of the classification of organisms
Phylogeny
The evolutionary history of a group of organisms; phylogenetic relationships are evolutionary relationships
Systematics
The science organizing groups of organisms into a hierarchy
The Three Domains
Bacteria
Archaea
Eukarya
Bacteria
Domain of prokaryotic organisms, characterized by peptidoglycan cell walls
Archaea
Domain of prokaryotic cells lacking peptidoglycan
Eukarya
All eukaryotes (animals, plants, fungi, and protists)
Phylogenetic Tree of Life
is a branching diagram or “tree” showing the inferred evolutionary relationships among various biological species or other entities
Furthest from root of tree is the most recently evolved
discovered the domain Archae
Carl Woese
generated by comparing conserved ribosomal RNA (rRNA) sequences
Molecular Clock
an evolution timeline based on nucleotide sequences in organisms
Scientific Nomenclature
Genus and Specific Epithet
Taxonomic Hierarchy
Domain Kingdom Phylum Class Order Family Genus Species Strain (subspecies)
Linnaeus developed
Prokaryotic Species
A population of cells that share certain rRNA sequences; in conventional biochemical testing, it is a population of cells with similar characteristics
Culture
Grown in laboratory media
Clone
Population of cells derived from a single cell
Strain
Genetically different cells within a clone
Classification
Placing organisms in groups of related species
Identification
Matching characteristics of an “unknown” organism to lists of known organisms
Identification Methods
Morphological Characteristics Differential Staining Biochemical Tests Serology Phage typing DNA Composition
Morphological Characteristics
Useful for identifying eukaryotes
Differential staining
Gram staining, acid-fast staining
Biochemical Tests
Determines presence of bacterial enzymes
Serology
Based on specific antibody binding to a microbe
Phage typing
a phage is a bacterial virus that infects specific bacteria
DNA Composition
The moles percentage of guanine plus cytosine in an organism’s DNA
