Biological organisms are classified in a hierarchical system to reflect evolutionary relationships. The classification system has seven main levels from broadest to most specific: kingdom, phylum, class, order, family, genus, and species. This system allows scientists to organize the diversity of life and compare new organisms to existing groups. Examples are provided of the full seven-level classifications for several organisms, like Homo sapiens for humans and Panthera leo for lions.

1. Biological Classification

2. Why classify?
• Humans have developed
classification systems in order to
make sense of the abundant
biological diversity that exists in
nature.

3. Taxonomy
• the science of naming organisms
and assigning them to groups
• Taxonomists search for previously
unknown organisms, determining
their relationships to known
organisms, and giving them
names.

4. Chordata
Panthera
The Biological Classification System
• The system is hierarchical.
– Larger groups are more general and
smaller groups are more specific.
– For example, the phylum Chordata
includes both lions and lionfish, but the
genus Panthera includes only lions.

5. The Biological Classification System
• The system is phylogenetic.
– It is meant to reflect the evolutionary
interrelatedness among groups.
– For example, the grey wolf and the
dog both are placed in the genus
Canis because of their close
evolutionary relationship.

6. Seven Levels
of Taxonomic
Classification
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species

7. Kingdom, Phylum…what?
• An easy way to remember the
classification levels:
“King Philip Came Over
From Great Spain”
• Try to make up your own!

8. Seven Levels
of Taxonomic
Classification
for the…
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species
Grizzly Bear

9. Kingdom
• The most general of the seven
levels.
• Most biologists currently recognize
six different kingdoms:
Archaebacteria, Eubacteria,
Protists, Fungi, Plants, Animals

11. Phylum (plural: phyla)
• Each kingdom is subdivided into
smaller, more specific groups
called phyla.

13. Class
• Each phylum is subdivided into
smaller groups called classes.

15. Order
• Each class is subdivided into
smaller groups called orders.

17. Family
• Each order is subdivided into
smaller groups called families.

19. Genus (plural: genera)
• Each family is subdivided into
smaller groups called genera.

21. Species
• Each genus is subdivided into smaller
groups called species.
• The species is the most specific level
of classification.

23. Scientific Names
• The scientific name of an
organism contains two parts—the
name of the genus and the name
of the species.

24. Writing Scientific Names
• The rules for writing scientific names:
-CAPITALIZE the first letter of the genus name.
-Do not capitalize the species name.
-Both names must be underlined or italicized.
• Example: human = Homo sapiens

25. Seven Levels
of Taxonomic
Classification
for the…
• Kingdom-Animalia
• Phylum-Chordata
• Class-Mammalia
• Order-Carnivora
• Family-Felidae
• Genus-Panthera
• Species-leo
Lion

26. Seven Levels of Taxonomic
Classification
for the…
• Kingdom-Animalia
• Phylum-Chordata
• Class-Mammalia
• Order-Primates
• Family-Hominidae
• Genus-Homo
• Species-sapiens
Huma
n

27. Seven Levels
of Taxonomic
Classification
for the…
• Kingdom-Protista
• Phylum-Sarcodina
• Class-Rhizopoda
• Order-Amoebida
• Family-Amoebidae
• Genus-Amoeba
• Species-proteus
Amoeba

28. Seven Levels of
Taxonomic
Classification
for the…
• Kingdom-Animalia
• Phylum-Chordata
• Class-Mammalia
• Order-Carnivora
• Family-Canidae
• Genus-Canis
• Species-familiaris
Dog

29. Seven Levels
of Taxonomic
Classification
for the…
• Kingdom-Plantae
• Phylum-Tracheophyta
• Class-Anthophyta
• Order-Asterales
• Family-Compositae
• Genus-Taraxacum
• Species-officinale
Dandelion

30. Seven Levels
of Taxonomic
Classification
for the…
• Kingdom: Animalia
• Phylum: Chordata
• Class: Mammalia
• Order: Xenarthra
• Family:
Myrmecophagidae
• Genus Tamandua
Collared
Ant eat er

31. Assignment (Due Monday)
• Find and write down all seven major
levels of taxonomic classification for
the organism of your choice.