Classification
Chapter 2 Section 2
 Classification
– process of grouping
things based on their similarities
 Biologists use classification to
organize living things into groups so
that the organisms are easier to
study.
 Taxonomy – study of how living
things are classified
Why Do Scientists Classify?
 Divided
Aristotle
animals
into 2 types –
those with
backbones and
those without
backbones.
 Further divided
those groups
 System lasted
for 100s of
years
 1750s
system
still used today
 Organisms
placed into
groups based on
observable
features.
 Binomial
nomenclature (2
names)
The Naming System of Linnaeus
Organism’s scientific name = 2 names
1st name is its genus; a group that
contains similar, closely related
organisms
 2nd name is its species; group that can
mate with each other and produce
offspring that can reproduce


 Canis
lupus - 1st word capitalized,
italics or underlined, Latin
Binomial Nomenclature
Examples
North American field
pocket mouse
Scientific Names
Perognathus
californicus
 Perognathus
nelsoni
 Perognathus
spinatus

Another Example
Domain - Eukarya
 Did (domain)
 King (kingdom)
 Philip (phyla)
 Come (class)
 Over (order)
 From (family)
 Germany
 The
more
classification
levels that 2
organisms
share, the
(genus)
more
 Saturday
characteristics
(species)
they have in
common.
Levels of Classification
 Organisms
are placed into
domains and kingdoms based
on their cell type, their ability
to make food, and the
number of cells in their
bodies.
Domains and Kingdoms
Domain Eukarya
Domain Archaea
Kingdom Archeabacteria
Domain Bacteria
Kingdom
Eubacteria
New Classification System
Unicellular
 Prokaryotes (no nucleus)
 Some are heterotrophs (obtain their own
food). Some are autotrophs (make their
own food).

Domain Bacteria (Eubacteria)
 Unicellular
 Prokaryotes
 Autotrophs
& heterotrophs
Domain Archaebacteria
Kingdom Animalia
Kingdom Plantae
 Multicellular
 Multicellular
 Eukaryotes
 Eukaryotes
 Heterotrophs
 Autotrophs
Domain Eukarya
Kingdom Fungi
Kingdom Protista
 Multicellular
mostly
 Eukaryotes
 Heterotrophs
Domain Eukarya
“junk drawer”
 Anything that is
not an animal,
plant, or fungus
 Uni and
multicellular
 Auto and
heterotroph
