Ch 4 Flashcards
Define taxonomy
The science of classifying/naming organisms based on similar physiology/morphology
Define phylogeny
Classifying organisms by DNA sequencing/evolutionary sequences
Contributions of Carolus Linnaeus
Came up with taxonomy. Binomial nomenclature (genius, and specific epithet= species) believed life was divided into kingdoms; plantae and animalia.
Contributions of Robert Whittaker
Proposed taxonomic approach based on five kingdoms; animalia, plantae, fungi, protista, and morera (aka prokaryote).
Contributions of Carl Woese
Sequenced rRNA of prokaryotes to look for differences and determine relationships. Discovered that there are three distinct types; eukaryotes, bacteria, and Archaea.
Species
Group of organisms that can reproduce with one another in nature and produce fertile offspring.
Binomial nomenclature
Naming system is used for organisms, two names, genus and specific epithet.
Clone
Process of producing similar population of genetically identical individuals that occurs in nature when organisms produce asexually.
Strain
Population of cells derived from a single cell
Why is the traditional definition for species problematic for prokaryotes?
Prokaryote cells only do asexual (budding) which is where one cell makes a small protrusion with identical DNA in it, and eventually separates from the larger cell and gives rise to a new cell exactly identical to the parent cell/mother cell.
List the taxonomic groupings in descending order (most general to specific)
Domain, kingdom, phylum, class, order, family, genus, and species.
Mnemonic: dumb kids play chase on freeway goes flat.
Methods used for classification of microbes
Physical characteristics, nutrition, metabolism, serological tests, phage typing, and analysis of nucleic acids.
Cladogram
Shows evolutionarily relationships by comparing RNA sequencing
Dichotomous key
Series of paired statements so that only one of the two either/or choices, applies to any particular organism.
Physical characteristics
Morphology as well as cell morphology in oxygen requirements (aerobes vs anaerobes) in other environmental requirements, such as temperature, pH, osmolarity, and hydrostatic pressure.
