Chapter 4: Taxonomy Introduction Flashcards
Define: taxonomy
the science of classifying & naming organisms based of similar physiology or morphology
Define: species
a group of similar organisms that can interbreed & produce viable (living) offspring (Genus & Specific epithet= species)
Define: binomial nomenclature
The classification method used in the Linnaeus system of taxonomy, which assigned each species both a Genus & Specific epithet
Define: strain
population of cells derived from a single cell
Define: phylogeny
the study of organizing organisms based upon their evolutionary relationships
Define: cladogram (clado = branching)
prokaryotic cladograms are based on rRNA sequence information. Gives you an idea how closely related show evolved
Define:
dichotomous key
series of paired statements worded so that only one or two “either/or” choices apply to any particular organism
End with identification of organism Genus
Describe the aspects of taxonomy.
o Classification
o Naming
o Identification
Classification: assigning organisms to non-overlapping groups (taxa) based on mutual similarities
Naming: system of naming organisms (nomenclature)
Identification: practical science of determining that an isolated organism belongs to a particular taxon
Explain why the traditional definition for species is problematic for prokaryotes
Who is Linnaeus?
standardized how organisms are made
Genus + specific epithet = species
How did Whittaker change taxonomy?
proposed taxonomic approach based on five kingdoms: Animailia, Plantae, Fungi, Protista, & Monera (prokaryote)
-fallen out of date but easy & simple
-wasn’t using DNA
How did Woese change taxonomy?
o 3 domains of life (above Kingdom)
o rRNA comparison
3 Domains: Bacteria, Archaea, Eukarya
-Realized there are 3 distinct types: Eukaryote, Bacteria, & Archaea ribosome part of cell involved make proteins & composed of proteins & pieces RNA
Be able to describe the 5 ways to classify an organism:
-physical characteristics
-nutrition and metabolism
-serological tests
- phage typing
-nucleic acid comparison
-Physical Characteristics:
MORPHOLOGY: visual characteristics; colony & cell, structure
(flagellum, capsule endospore) ex: morph unk.
OXYGEN REQUIREMNET: aerobes (w/O2) vs. anaerobe (w/o O2)
TEMPERATURE
pH
OSOMOLARITY: water to cell
HYDROSTATIC PRESSURE
-Nutrition & metabolism: determined by biochemical tests & media
(what does an organism eat?/ What waste products does it make?/ What metabolic pathways does it use? (respiration vs fermentation; photosynthesis; nitrogen-fixation)/ Does an organism have a specific enzyme? (catalase, urase)
Testing organisms: single tubes of media, inverted tubes to trap gas, 96 well plates each well had dif. nutrients cause dif. color when organism consume nutrient
-Serological Tests: can antibodies stick to the organism? ex: rapid strep test
Agglutination: clumping of cells due to binding of antibody
-Phage Typing: bacteriophage is a virus that infects bacteria; each phage is specific to a species of bacteria (makes use of bacterial viruses to identify bacteria)
-Analysis of nucleic acids: how similar are the DNA or RNA sequences? compare sequence of unknown w/sequences in a database of known organisms
What’s the difference between a cladogram & a dichotomous key?
Dichotomous key is questions in either/or form to identify organism genus
Cladogram is a branching graph that shows evolutionary relationships based on rRNA sequencing. gives you an idea how closely related & how evolved
List the taxonomic groupings in descending order. (Hint: starts with Domain)
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
