Chapter 18 – Classification of Organisms
Taxonomy – the science of classifying organisms
Why do we need to classify organisms using a universal code? biologists need a CONSISTENT naming protocol
Carolus Linnaeus - developed the universal system
He also created a system where we place all organisms into a few *large* groups - KINGDOMS - and
then those groups are further divided into smaller groups
Classification of Organisms


Kingdom
o Phylum
 Class

Order
o Family
 Genus
 Species
Each group gets smaller and more specific - just think of the way you file things on your computer into
folders and subfolders.
The system of naming is called Binomial nomenclature – which means it is a 2-name system
How to write a the scientific name:
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Scientific names must either be underlined or italicized
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The genus is always capitalized, the species is lowercase
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Can be abbreviated. Ex. F. leo and F. tigris
Kingdom
Phylum
Class
Order
Family
Genus
Species
Human
Animalia
Chordata
Mammalia
Primate
Hominidae
Homo
Sapien
Lion
Animalia
Chordata
Mammalia
Carnivora
Felidae
Panthera
Leo
Tiger
Animalia
Chordata
Mammalia
Carnivora
Felidae
Panthera
Tigiris
Pintail Duck
Animalia
Chordata
Aves
Anseriformes
Anatidae
Anas
Acouta
Write the scientific names of each organism – follow the rules!
Human:
Lion:
Tiger:
Pintail Duck:
**Check for Understanding**
1. Which two taxa groups are used for an organism's scientific name? _______________________________
2. Which of the following pairs is MOST closely related? (circle)
Acer rubrum & Acer saccharum
Acer rubrum & Chenopodium rubrum
3. The system we use for naming is called _________________ nomenclature.
The Kingdoms
There are currently 6 kingdoms – all organisms can be placed into one of those 6.
Classification into a kingdom is based on certain criteria
Number of cells – unicellular / multicellular
Type of cell - _prokaryote / eukaryote
_________
Cell Wall makeup - _no / yes (chitin, peptidoglycan, cellulose_How it obtains energy - _autotroph / heterotroph
Recently, scientists have added a group above Kingdom. Three groups, called DOMAINS, contain each of the six
kingdoms.
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Domain Eukarya - includes organisms composed of eukaryotic cells (plants, animals, fungi, protists)
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Domain Bacteria - includes all prokaryotic cells, Kingdom Eubacteria
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Domain Archaea - includes only ancient bacteria, Archaebacteria
•