CLASSIFICATION

THE IMPORTANCE OF CLASSIFICATION In biology, the practice of naming and

classifying organisms is called taxonomy.

Biologists use taxonomic systems to organize their knowledge of organisms. These systems attempt to provide consistent ways to name and categorize organisms.

THE PROBLEM WITH COMMON NAMES Common names are not organized into a

system. One species may have many different common names.

For example: Robins in Great Britain are a completely different bird than robin in the United States.

Great Britain Robin

SCIENTIFIC NOMENCLATURE Carl Linnaeus, 1750s, developed a

consistent naming system still used today.

Each species has 2 names (binomial nomenclature); Genus and species name

Common Name: African LionScientific name: Panthera leo

NAMING RULES All scientific names for species are

made up of two Latin or Latin-like terms. All members of a genus share the genus

name as the first term The second term is the species identifier

and is often descriptive.

Common name: HoneybeeScientific name: Apis melliferaMellifera = Latin for honey

THE LINNAEAN SYSTEMDomain: Eukarya

LEVELS OF THE LINNAEAN SYSTEM Each level has its own set of names for

taxa (groups) at that level Each taxon is identified based on shared

traits Similar species are grouped into a

genus; similar genera are grouped into a family, etc.

Order: Lagomorpha

KINGDOMS AND DOMAINS For many years, scientists recognized

only two kingdoms: Plantae and Animalia

Today, there are 6 kingdoms for classifying organisms; Archaebacteria, Eubacteria, Protista, Fungi, Plantae, and Animalia

These 6 Kingdoms each belong to a larger category: The Domain

DOMAIN BACTERIA Domain Bacteria is equivalent to

Kingdom Eubacteria These are all prokaryotic unicellular organisms They have a strong exteriorcell wall and a unique geneticsystem.They have the same kind ofcell membrane lipids as Eukaryotes do

DOMAIN ARCHAEA Equivalent to the Kingdom Archaebacteria These organisms are prokaryotic and

unicellular They have a unique cell wall and

membranes and a unique genetic system The genetic system of Archae share some

similarities with Eukarya that they do not share with Eubacteria

Scientists think that Archaea began to evolve in a separate lineage from bacteria early in Earth’s history & some gave rise to Eukaryotes.

ARCHAEBACTERIA Were first found by scientists in extreme environments, such as salt lakes, the deep ocean or hot springs that exceed 100 degrees Celsius. Called extremophiles. Some live in O2-free environments. These are called methanogens.

DOMAIN EUKARYA Made up of Kingdoms: Protista, Fungi,

Plantae, and Animalia All have eukaryotic cells with a complex

internal structure