Classification Biology I

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

6 Kingdom Proposal 6 Kingdom Classification System –Kingdom Eubacteria: true bacteria (formerly in kingdom monera) –Kingdom Archebacteria: extremophiles (formerly in kingdom monera) –Kingdom Protista (same) –Kingdom Fungi –Kingdom Plantae –Kingdom Animalia

3 Domain Proposal 3 Domain System: –Archaea: prokaryotes; extremophiles –Eubacteria: prokaryotes; true bacteria –Eukarya: eukaryotes ProtistaFungiPlantaeAnimalia

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: Kingdom Phylum Class Order Family Genus Species

Classification Taxa Kingdom Phylum Class Order Family Genus Species Together, these make up a species’ scientific name Example: Ursus americanus Common Name: American Brown Bear 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.

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 Amoeba ParameciumGiardia Water MoldSlime Mold Euglena Dinoflagellates Diatom Brown AlgaeGreen Algae

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

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

Kingdom Animalia All eukaryotic, multicellular, heterotrophic, motile (most) organisms Common Phyla: –Porifera (sponges, corral) –Cnidaria & Ctenophora (jellyfish and similar animals) –Platyhelmenthes (flat worms, tapeworms) –Nematoda (small unsegmented worms) –Mollusca (inc. clams, oysters, etc..) –Annelida (segmented worms) –Echinodermata (starfish and anemones) –Arthropoda (crustaceans, insects, spiders) –Chordata (those with spinal chords)

Human Classification Domain: Eukarya Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates 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 legsGo to # 2 1b. Organism has more than 4 legsGo to # 20 2a. Organism has a tailGo to # 3 2b. Organism has no tailGo to # 35 3a. Organism has stripesBengal Tiger 3b. Organism has no stripesAfrican 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 fur3 2b. Organism has no visible fur20 3a. Organism lives in warm climates7 3b. Organism lives in cold climates4 4a. Organism has brown or black furUrsus Americanus 4b. Organism has white furUrsus Maritimus

Note Guide Who was Linnaeus? What are taxa? The old classification system is: The new classification system choices are: –1. –2. How are organisms scientifically named? What is the difference between the 3 domains? –1. –2. –3. Name and describe the differences between the 4 kingdoms in Eukarya: –1. –2. –3. –4.

Note Guide (pg. 2) Name and describe (or give an example of) each of the 10 phyla in Animalia: –1. –2. –3. –4. –5. –6. –7. –8. –9. –10. What is the purpose of a dichotomous key? How do you read a dichotomous key?