Classification I: Intro IB Biology

Classifying Organisms The science of classifying organisms is called taxonomy The “father of modern taxonomy” was Carolus Linnaeus (Carl von Linné) Organisms are grouped into “taxa” based on their similarities to each other

The Old System 5 Kingdom Classification System: Monera: all prokaryotes Protista: single-celled eukaryotes (protists) Fungi: multi-cellular heterotrophic sessile eukaryotes Plantae: multi-cellular autotrophic sessile eukaryotes Animalia: multi-cellular heterotrophic motile eukaryotes

The New System 3 Domain System: Archaea: prokaryotes; extremophiles Eubacteria: prokaryotes; true bacteria Eukarya: eukaryotes Protista Fungi Plantae Animalia

Under Domain and Kingdom Organisms are grouped into smaller and smaller groups all the way down to their species A species is the most specific grouping and includes only organisms that can interbreed with each other and produce fertile offspring To remember the grouping order – just remember: King Philip Came Over For Gold Specks

King Philip Came Over For Gold Specks Classification Taxa King Philip Came Over For Gold Specks Kingdom Phylum Class Order Family Genus Species Note: Scientific names are always written with the first letter of the genus capitalized, the first letter of the species lower-case, and the whole thing underlined in italics. Together, these make up a species’ scientific name Example: Ursus americanus Common Name: American Brown Bear

Domain Archaea Formerly part of the kingdom monera Microbiologists who study bacteria determined that the DNA of these are much different from other, true bacteria Most Archaea live in extreme conditions (very hot, acidic/basic, sulfurous, etc)

Domain Eubacteria Formerly a part of the kingdom monera Name means “true bacteria” These are the kind of bacteria likely to make us sick, live in our gut to help us digest food, or be used in the making of cheese

Domain Eukarya Contains all of the eukaryotes (organisms with a nucleus in their cells) Protista Fungi Plantae Animalia

Kingdom Protista Includes All Protists: Eukaryotic Unicellular Animal-Like Protists (protozoans) Pseudopods, Ciliates, Flagellates Examples: Amoeba, Paramecia, Giardia Plant-Like Protists (autotrophic) Euglenoids, Dinoflagellates, Diatoms, Green/Red/Brown Algae Fungus-Like Protists Examples: Water molds, slime molds

Kingdom Protista Animal-Like (Protozoans) Fungus-Like Plant-Like Paramecium Giardia Amoeba Fungus-Like Plant-Like Water Mold Slime Mold Diatom Euglena Green Algae Brown Algae Dinoflagellates

Kingdom Fungi All eukaryotic, multicellular, heterotrophic, sessile organisms Includes: molds, mushrooms, rusts, lichens Mycorrhizal associations allow plants to absorb more water and nutrients from the soil

Kingdom Plantae All eukaryotic, multicellular, autotrophic, sessile organisms Produce their own food from sunlight and carbon dioxide Common Phyla: Bryophyta (mosses) Pteridophyta (ferns) Coniferophyta (conifers, like pine trees) Angiospermophyta (angiosperms, like flowering plants

Coniferophytes (Pine Trees) Kingdom Plantae Primitive Plants Bryophyte (Moss) Pteridophyte(Fern) Complex Plants Pteridophyte(Fern) Coniferophytes (Pine Trees) Angiosperm; Dicot Angiosperm; Monocot

Kingdom Animalia All eukaryotic, multicellular, heterotrophic, motile (most) organisms Common Phyla: Chordata (those with spinal chords) Annelida (worms) Mollusca (inc. clams, oysters, etc..) Arthropoda (crustaceans, insects, spiders) Porifera (sponges) There are about 40 such Phyla

Human Classification Domain Eukarya Kingdom Animalia Phylum Chordata Class Mammalia Order Primate Family Hominidae Genus Homo Species Sapien

Dichotomous Keys Used to help identify unknown specimen Work by asking yes or no questions whose answers lead the reader to the correct taxa for the organism Simple Example: 1a. Organism has 4 legs Go to # 2 1b. Organism has more than 4 legs Go to # 20 2a. Organism has a tail Go to # 3 2b. Organism has no tail Go to # 35 3a. Organism has stripes Bengal Tiger 3b. Organism has no stripes African Lion

Dichotomous Key Try this one: 1a. Organism walks on all 4 legs (quadruped) 2 1b. Organism walks on 2 legs (biped) 8 2a. Organism has visible fur 3 2b. Organism has no visible fur 20 3a. Organism lives in warm climates 7 3b. Organism lives in cold climates 4 4a. Organism has brown or black fur Ursus Americanus 4b. Organism has white fur Ursus Maritimus