Taxonomy

Taxonomy is the classifying of species into hierarchy of taxa (groupings) so that each species has a universal name around the world.

Binomial Nomenclature ➜ a system of naming organisms by using two names, the genus name and the species name. Example: Castor canadensis ➜ castor meaning “beaver” and canadensis meaning “from Canada”.

The first name is the genus and the second is the species Genus ➜ a class of things with common characteristics Species ➜ group of organisms that can interbreed naturally and produce viable offspring

The genus and species are ALWAYS italicized, and the genus is capitalized, where the species is not! Also, once the full binomial nomenclature name has been written once in a piece of work, you can use the initial for the genus afterwards (i.e. C. canadensis)

domain

the highest level of taxa used to be Kingdom, however, studies of ribosomal RNA (rRNA) lead to discovery of huge differences amongst prokaryotic cells (cells with no true nucleus)  as a result, the scientist responsible for the research, Carl Woese, added an eighth level for taxonomic classification, Domain

• (Eu)Bacteria ➜ “true” bacteria, prokaryotes that have no organized nucleus and no membrane bound organelles. ➜ contains the Kingdom of Eubacteria • Archaea ➜ “ancient” bacteria which are also prokaryotic, but live in extreme environments ➜ contains the Kingdom of Archaebacteria • Eukaryota ➜ single-celled and multicellular organisms which all have their DNA contained in a nucleus. ➜ contains the Kingdoms of Protista, Fungi, Animalia and Plantae

• Eubacteria ➜ A group of prokaryotic (lack nuclei) microorganisms (microscopic) that live in a wide variety of environments and reproduce asexually. They also can cause diseases. Examples: bacteria, cyanobacteria • Archaebacteria ➜ A group of prokaryotic microorganisms distinct from Eubacteria that possess an unusual cell wall structure and that thrive in harsh environments such as salt lakes and thermal vents Examples: methanogens, extreme thermophiles • Protista ➜ Mostly single celled, can be autotrophs or heterotrophs (or both), live in aquatic or moist habitats Examples: algae, protozoa • Fungi ➜ A group of organisms that are plant-like but lack chlorophyll. They produce spores and feed on organic matter. Examples: moulds, yeast, mushrooms, toadstools • Plantae ➜ A group of multicellular organisms that are mostly autotrophs, and can reproduce sexually or asexually. Most are terrestrial. Examples: mosses, ferns, conifers, flowering plants • Animalia ➜ In general they are multicellular, heterotrophs (feed by consuming other organisms) that are capable of locomotion and responsive to their environment. Examples: sponges, worms, lobsters, dogs, humans

the history of evolution of organisms

a series of choices that lead to new branches of the key, and the end result is the correct name of the organism being identified.