CHAPTER 9 LESSON 2
Classifying Organisms
ESSENTIAL QUESTIONS
What methods are used to classify living
things?
Why does every species have a scientific
name?
NEW VOCABULARY
Binomial Nomenclature
Species
Genus
Dichotomous Key
Cladogram
CLASSIFYING LIVING THINGS
Carolus Linnaeus was one of the first scientists to
classify organisms (What does it mean to classify
things?)
He classified them into 2 main groups called kingdoms
Based on similar structures
DETERMINING DOMAINS
 Systematics: The current classification method for
organisms
 Uses all known evidence to classify organisms
 Cell type
 How food and energy are obtained
 Structure and function of features
 Common ancestry
 Molecular analysis
 Organisms are now classified into one of 3 Kingdoms and then
into one of 6 Kingdoms.
DOMAINS AND KINGDOMS
SCIENTIFIC NAMES
 Binomial Nomenclature: is a system for naming
organisms with 2 word scientific name:
 Species name (group of organisms that have similar
traits and are able to produce fertile offspring)
 Genus name (group of similar species)
 Example: Ursus arctos (Grizzly Bear)
 Ursus = Genus
 arctos = Species
SCIENTIFIC NAMES (CONTINUED)
 What domain
does the
Grizzly Bear
belong to?
 What
kingdom?
SCIENTIFIC NAMES (CONTINUED)
Binomial nomenclature was developed by
Linneaeus
Scientific names are important because each
species has its own scientific name
These are the same worldwide
Scientists don’t get confused about which
species they are talking about
CLASSIFICATION TOOLS
Dichotomous key: is a series of descriptions
arranged in pairs that lead the user to the
identification of an unknown organism.
Cladogram: is a branched diagram that
shows the relationship among the
organisms, including common ancestors.
DICHOTOMOUS KEY
CLADOGRAM
QUESTION:
Is my poster of life a
dichotomous key or a
cladogram?
REVIEW
How many scientific names does each
organism have?
A.1
B.2
C.3
D.Many
REVIEW
Which of these refers to the system for
naming organisms with two identifying
scientific terms?
A.Genus
B.Cladogram
C.Binomial Domains
D.Binomial Nomenclature
REVIEW
Which of these refers to a series of
descriptions arranged in pairs that help
identify an unknown organism?
A.Dichotomous key
B.Domain
C.Cladogram
D.Genus