Taxonomy

Taxonomy

• Modern taxonomy is based on the work of Carrolus Linnaeus

• The taxa are: Kingdom, phylum, class, order, family, genus, species (KPCOFGS)

• There are three domains and five kingdoms• How do we know if an organisms is a member

of the same species

Domains

• The three domains (or superkingdoms) are the bacteria, the archaea and the eukarya

• The kingdom monera is no longer used and because of the this the prokarya are spread out among the bacteria and the archaea

Domain Bacteria

• Are all single celled prokaryotes• Some are anaerobes and some are aerobic• The bacteria play a vital role as decomposers in

the environment• Many are pathogens – disease causing organisms• Many are important in genetic engineering• Some bacteria carry out simple sexual

reproduction called conjugation

Domain Bacteria

• Bacteria have a thick rigid cell wall composed of peptidoglycan

• Some carry out photosynthesis• Some carry out chemosynthesis

Domain Archaea

• Unicellular• Prokaryotic• Include the extremophiles

- Methanogens – Live in methane rich environments such as the large intestine – e. coli

is an example- Halophiles – High salt environments- Thermophiles – High temperature environments

Domain Eukarya

• All organisms have a nucleus and internal membrane bound organelles

• Eukarya include the four remaining kingdoms: Protista (protists) , Fungi (fungus), Plantae (plants), and animalia (animals)

Domain Eukarya – Kingdom Protista

• This kingdom contains the widest variety of organisms

• Most are single-celled, but some are primitive multicellular

• They can be heterotrophs or autotrophs• Examples of heterotrophs are paramecium

and amoeba• Examples of autotrophs are euglenia

Domain Eukarya – Kingdom Protista

• Protists move using either cilia (paramecium), pseudopods (amoeba), or flagella (euglenia)

• Protists include organisms that do not fit well into the fungus or plant kingdoms such as seaweeds and slime molds

• Some carry out the simple form of sexual reproduction called conjugation

• Some are pathogens causing diseases such as amoebic dysentery and malaria

Domain Eukarya – Kingdom Fungus

• All are heterotrophic eukaryotes• They may be either unicellular (yeast) or

multicellular• Fungus carry out extracellular digestion• Fungi are decomposers• Fungi are saprobes – Saprobes are organisms that

obtain nutrients from decaying organic matter

• There cell walls are made of chitin – not cellulose

Domain Eukarya – Kingdom Fungus

• Certain fungus live in symbiotic mutualistic relationships with algae forming lichens

• Lichens can survive on cold, bare rock. They are often pioneer species – the first organsms to colonize an area

• Fungi reproduce by budding (yeast), spore formation (bread mold) or fragmentation

• They can also reproduce sexually

Domain Eukarya – Kingdom Fungus

• Many fungi are edible• Fungi are used in the production of bread,

beer and wine• Many fungi are toxic• Some are pathogens – athlete foot is caused

by a fungus

Domain Eukarya – Kingdom Plantae

• All plants are multicellular, nonmotile, autotrophic eukaryotes

• Their cell wall are made of cellulose• All plants carry out photosynthesis• All plants store carbohydrates as starch (long

chains of glucose molecules)• All plants reproduce sexually• Some plants have vascular tissue (xylem and

phloem) and some do not

Domain Eukarya – Kingdom Plantae

• Some produce seeds inside of cones (gymnosperms) and some produce seeds inside of flowers (angiosperms)

Domain Eukarya – Kingdom Animalia

• All are heterotrophic, multicellular eukaryotes• Most are motile• Most animals reproduce sexually (the

exception being the porifera and some cnidarians)

• The traditional way of classifying animals is based on anatomical structure (homolgous structures ) or embryological development

Domain Eukarya – Kingdom Animalia

• There are nine main phyla of animals:porifera, cnidaria, platyhelminthes,

nematodes, annelids, mollusks, arthropods,echinodermata, and chordates