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