Classification
Notes
Why do we classify?
 Classification puts organisms into groups
by looking at characteristics (traits) they
share.
Taxonomy
 Classifying
living things
into groups
based on their
body
structures
(anatomy),
DNA or other
traits.
Carolus Linneaus
 Swedish botanist,
lived 1707-1778
 Invented binomial
nomenclature, the 2word naming system
we still use today to
classify organisms
 Called “the father of
taxonomy.”
Binomial Nomenclature
 Gives a unique 2-word, Latin, scientific
name to all living things
 Genus is capitalized; species is not; both
are italicized
 Examples: Homo sapiens = human
Felis domesticus = cat
Panthera tigris = tiger
TURN & TALK
 What are these animals’ scientific
names? Common Chimpanzee Paramecium
name
Domain
Eukarya
Eukarya
Kingdom
Animalia
Protista
Phylum
Chordata
Ciliophora
Class
Mammalia
Ciliatea
Order
Primates
Peniculida
Family
Hominidae
Paramecidae
Genus
Pan
Paramecium
species
troglodytes
caudatum
(scientific
name)
?
?
What would
you call this
creature?
Why are scientific names
better than common
names?
 Ex: pill bug, rolly polly, potato bug
 Common names for the same species
are different and confusing
 Binomial Nomenclature uses Latin (a
“dead” unchanging language) that is
understood by scientists worldwide
 Scientific Name: Armadillidium vulgare
8 taxa of classification:
1.
2.
3.
4.
5.
6.
7.
8.
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Binomial name or
Scientific Name
8 taxa of classification
DOMAIN
“Trick” to remember the 8
taxa of classification:
 Dumb
 King
 Phillip
 Came
 Over
 For
 Grape
 Soda
Species
 Species is the
smallest, most
specific group in
classification
 Organisms in the
same species
can reproduce
together AND
their offspring are
fertile.
Tool: Phylogeny
a “family tree” that classifies
organisms by their evolutionary
history
Tool: Cladogram
 Shows older traits (bottom)
 Shows newer or “derived” traits (top)
Tool: Dichotomous Key
 Helps identify organisms
 Questions with 2 answer choices lead
you through the key until you find the
correct organism
END
Vocabulary
 These are words you must know when
classifying organisms.
prokaryote
• Organism that doesn’t have a
nucleus
• Its DNA is “loose” inside the cell
• All bacteria are prokaryotes.
Eukaryote
• An organism that has a nuceus
with DNA inside.
• All protists, fungi, plants &
animals are eukaryotes.
Heterotroph
 An organism that has to eat or consume
nutrition.
Autotroph
 An organism that automatically feeds
itself.
 It makes its own food by photosynthesis
or chemosynthesis.
unicellular
 An organism with only 1 cell
What does
multicellular mean?
• Having more than one cell
Cell wall
 A hard covering outside the cell
membrane.
 Cells of bacteria, fungi and plants have
cell walls.
Cell membrane
 A flexible covering outside of all cells!
 All organisms have cell membranes.
 It lets good stuff pass in and keeps bad
things out.
motile
 Able to move
 All animals, some bacteria & protists are
motile.
sessile
 Not able to move
 All plants are sessile.
Sexual reproduction
 Involves 2 parents
 Some sexual reproduction takes place
outside the parents’ bodies. They don’t
touch!
Asexual reproduction
 Involves only 1 parent.
 Examples: 1 bacterium divides to make 2
bacteria