17.1 The Linnaean System of Classification
Class Notes 2: Classification
17.1 The Linnaean System of Classification
I.
Classification
A. Organisms can be classified based on physical
similarities.
B. Linnaeus developed the scientific naming system still used
today.
Taxonomy is the science of naming and classifying organisms.
White oak:
Quercus alba
17.1 The Linnaean System of Classification
C. Binomial nomenclature is a two-part scientific naming
system.
1. uses Latin words
2. scientific names always written in italics
3. two parts are the genus name and species descriptor
17.1 The Linnaean System of Classification
D. A genus includes one or more physically similar species.
1. Species in the same genus are thought to be closely
related.
2. Genus name is always capitalized.
E. A species descriptor is the second part of a scientific name.
1. always lowercase
2. always follows genus
name; never written alone
Tyto alba
17.1 The Linnaean System of Classification
II. Linnaeus’ classification system has seven levels.
A. Kingdom,
phylum, class,
order, family,
genus, species.
B. Levels get
increasingly
specific from
kingdom to
species.
17.1 The Linnaean System of Classification
III. Cladistics
A. The Linneaen system of classification only
uses physical similarites.
B. Modern classification is called cladistics and
is based on evolutionary evidence:
1. Fossil Records
2. DNA similarities
17.1 The Linnaean System of Classification
IV. Cladograms
A.
B.
A cladogram is an evolutionary tree that
groups organisms together by common
ancestry.
A clade is a group of species that shares a
common ancestor.
17.1 The Linnaean System of Classification
V. Kingdoms
A. Classification has changed over time.
B. Until 1866, only two kingdoms- animalia and
plantae existed.
C. Over time, the kingdoms protista, fungi, archae,
and bacteria were added.
17.1 The Linnaean System of Classification
IV. Domains
A. Domains are above (more general than) the kingdom level.
1. Proposed by Carl Woese based on rRNA studies of
prokaryotes
2. The three domains are Bacteria, Archae, and Eukarya
17.1 The Linnaean System of Classification
B. Domain Bacteria includes prokaryotes in the
kingdom Bacteria.
1. one of largest groups
on Earth
2. classified by shape,
need for oxygen, and
diseases caused
17.1 The Linnaean System of Classification
C. Domain Archaea includes prokaryotes in the
kingdom Archaea.
1. cell walls chemically
different from bacteria
2. differences discovered by
studying RNA
3. known for living in
extreme environments
17.1 The Linnaean System of Classification
D. Domain Eukarya includes all eukaryotes.
1. kingdom Protista
17.1 The Linnaean System of Classification
D. Domain Eukarya includes all eukaryotes.
1. kingdom Protista
2. kingdom Plantae
17.1 The Linnaean System of Classification
D. Domain Eukarya includes all eukaryotes.
1. kingdom Protista
2. kingdom Plantae
3. kingdom Fungi
17.1 The Linnaean System of Classification
D. Domain Eukarya includes all eukaryotes.
1. kingdom Protista
2. kingdom Plantae
3. kingdom Fungi
4. kingdom Animalia
17.1 The Linnaean System of Classification
Summary
What are the 2 parts in binomial nomenclature? What are
the 7 levels of Linnaean nomenclature? What is the
most general? What is the most specific?