Classification
8a Define taxonomy and recognize the importance of
a standardized taxonomic system
8b Categorize organisms using a hierarchical
classification system based on similarities
and differences shared among groups
8c Compare characteristics of taxonomic groups
including archaea, bacteria, protists, fungi, plants
and animals
What’s my name?
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Mountain lion
Cougar
Puma
Panther
Catamount
Taxonomy
• the naming, describing, and
classifying organisms based
on characteristics
Carolus Linnaeus
• Father of
taxonomy
Binomial Nomenclature
• formal system of naming
organisms by giving each a name
composed of two parts, both of
which use Latin
Scientific Names
• The first word is the organism’s Genus
(closely related species)
• The second word is the organism’s
species
• Genus species
Homo sapiens
Felis concolor
Liquidambar styraciflua
Canis lupus
Flowchart
Linnaeus’s System of Classification:
General to Specific
Section 18-1
Kingdom
Phylum
Class
Order
Family
Genus
Species
Why classify?
• To group organisms according
to similarities
• To name organisms in a way
that all scientists across the
world can communicate (to get
around language barriers)
But scientific names can change…
• With new discoveries,
we can re-classify
organisms
– “Chinese tallow tree”
changed from Sapium
sebiferum toTriadica
sebifera
Modern Evolutionary Classification
• The old Linnaeus way of using visible physical
similarities puts organisms that are very
different in the same groups.
• So, now organisms are grouped according to
characteristics that show common ancestry.
• Phylogeny – the study of evolutionary
relationships among organisms.
• All members of a genus share a recent common
ancestor.
Example: Barnacles and
Limpets
Traditional Classification Versus Cladogram pg. 452
Appendages
Crab
Conical Shells
Barnacle
Limpet
Crustaceans
Crab
Gastropod
Barnacle
Limpet
Molted
exoskeleton
Segmentation
Tiny free-swimming larva
CLASSIFICATION
BASED ON VISIBLE
SIMILARITIES
CLADOGRAM
Example: Barnacles and Limpets
• Adult barnacles look and act like limpets.
• Limpets have similar insides to a snail and
don’t shed their shells like a snail –
mollusks.
• Barnacles have similar anatomy and
development to crabs – crustaceans.
• So, barnacles are grouped with crabs and
limpets are grouped with snails.
Cladogram
• diagram that shows the
evolutionary relationships among
organisms
• The closer together in a relational
“line” the organisms are, the more
closely they are related (the more
recent their common ancestor)
• The more similar the DNA the more
recently they shared a common
ancestor and the more closely they
are related.
Derived Character
• trait that is shared by organisms with a
recent common ancestor
Clade
• Group consisting of its ancestor and all its
descendants
Cladogram of Six Kingdoms
and Three Domains, pg. 460
DOMAIN
ARCHAEA
DOMAIN
EUKARYA
Kingdoms
DOMAIN
BACTERIA
Eubacteria
Archaebacteria
Protista
Plantae
Fungi
Animalia
http://ccl.northwestern.edu/simevolution/ob
onu/cladograms/Open-This-File.swf
Figure 3
D
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A
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Cells
F
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Mammary glands
E
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Feathers
C
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Lungs
B
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Four limbs
Dichotomous Key
• Series of ordered steps you follow
to ID an organism
• To use, you read both options,
decide which variation is best,
and move on to the next step.
Review
• Prokaryote vs. Eukaryote
Review
• Unicelluar vs. Multicellular
Review
• Autotroph vs. Heterotroph
3 Domains
• Recently, new discoveries at the molecular
level of organisms have caused a new
way to categorize: domains.
• Eukarya – protists, fungi, plants, and
animals
• Bacteria – same as eubacteria
• Archaea – same as archaebacteria
The 6 Kingdoms
• Eubacteria – normal bacteria (strep, E. coli)
• Archaebacteria – bacteria that live in extreme
conditions and are usually anaerobic (hot
springs, black mud, etc.)
• Protista – most microorganisms (one or only few
cells)
• Fungi – mushrooms, yeasts, mold
• Plantae – plants
• Animalia - animals
Eubacteria
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Common term: bacteria
Cell type: prokaryote
# of cells: unicellular
Cell walls: present; with peptidoglycan
Type of nutrition: autotroph or
heterotroph
Eubacteria
• Examples
– E. coli
– Streptococcus
Archaebacteria
• Common term: none, this is a rare type of
organism that lives in extreme places like
hot springs
• Cell type: prokaryote
• # of cells: unicellular
• Cell walls: present; without
peptidoglycan
• Type of nutrition: autotroph or
heterotroph
Archaebacteria
• Examples
– Halobacterum (loves
salt)
– Thermoproteus (likes
hot water)
Protista
• Common terms: protists or single-celled
organisms
• Cell type: eukaryote
• # of cells: most unicellular; some
colonial; some multicellular
• Cell walls: some have cellulose cell
walls and chloroplasts
• Type of nutrition: autotroph or
heterotroph
Protista
• Poorly classified group
(basically, if an organsisms
doesn’t fit anywhere else, they
put it here
• Examples
– Amoeba
– Paramecium
– Algae
Fungi
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Common term: fungus
Cell type: eukaryote
# of cells: most multicellular; some unicellular
Cell walls: present; made of chitin
Type of nutrition: heterotroph
Fungi
• Examples
– Mushrooms
– Yeast
– Mold
Plantae
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Common term: plant
Cell type: eukaryote
# of cells: multicellular
Cell walls: present; made of cellulose;
chloroplasts present
• Type of nutrition: autotroph (use
photosynthesis)
Plantae
• Examples
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Mosses
Ferns
Pine trees
Flowering plants
Grass
Animalia
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Common term: animal
Cell type: eukaryote
# of cells: multicellular
Cell walls: no cell wall or chloroplasts
Type of nutrition: heterotroph
Animalia
• Examples
– Sponge
– Insects
– Spiders
– Fish
– Birds
– Reptiles
– Mammals