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Classification is the grouping of living
organisms according to similar structures and
functions
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Aristotle grouped animals according to the way
they moved
Today’s system developed by Carolus Linnaeus
Organization of Biological Diversity:
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Domain (often not even used)
Kingdom
Phylum
Class
Order
Family
Genus
Species
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A taxonomic category that is based on
fundamental differences among organisms
Three main domains:
◦ Bacteria
◦ Archaea
◦ Eukarya
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Taxonomic category made up of related phyla
Six kingdoms currently recognized for living
organisms
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Bacteria
Archaea
Protista
Plantae
Animalia
Fungi
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Prokaryotes (lack nucleus)
Unicellular (one cell)
Heterotrophic (most)-eat other organisms for
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energy
All bacteria are in the same domain and kingdom,
which is not true for a lot of organisms!
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Examples: E. Coli, Streptococcus
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Prokaryotes
Unicellular
Live in extreme environments
Ex: Sulfolobus acidocaldarius(grow in
volcanos), Methanogens (produce methane)
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Eukaryotes (contain nuclei)
Multicellular (multiple cells making up
organism)
Four kingdoms in this domain
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Protista
Animalia
Fungi
Plantae
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Mainly unicellular
Heterotrophic or Photosynthetic (use light as
energy)
Ex: Protozoa, slime molds
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Heterotrophic
Contain a nervous system
Ex: Us!!, Fish, Bats, Snakes (lots of examples!)
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Heterotrophic
Absorb nutrients
Contain cell walls of chitin (distinguishes
them from plants!)
Ex: mushrooms, truffles
“The latest auction was for two truffles weighing just
under 3 lbs total. $330,000 was paid for the fungal
delicacy.”
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Photosynthetic
Cell walls made with cellulose
Ex: Trees, Mosses, Ferns
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Now that we know how living organisms are
organized, let’s look at the differences in the
microscope!
While looking at the samples, I would like you
to note:
◦ Differences between organisms/cells in different
kingdoms
◦ Differences in organisms/cells in similar kingdoms
◦ Common features in plant slides