1. Classification of Organisms
Biology
Chapter 17

2. Classifying Organisms
Taxonomy: the science of describing, naming, and classifying organisms
Taxon: a group within a taxonomic system
Aristotle: classified organisms into two groups
Plants and animals
Why isn’t this useful?

3. Carolus Linnaeus
Devised system of grouping organisms into hierarchical categories
Using form and structure
Domain
Kingdom
Phylum
Class
Order
Family
Genus
species

4. Binomial Nomenclature
Two part naming system (scientific name)
Use genus and species name
Written in italics with genus name capitalized
In Latin because it is an unspoken language, so it never changes
Example
Humans: Homo sapiens

5. Systematics Phylogeny: the evolutionary history of a species
Phylogenetic Diagram (phylogenetic tree)
Looks like a family tree and has branching pattern that indicates how closely related subset taxa are thought to be

6. Cladistics Cladistics
A system the uses shared characteristics and derived characters as the only criteria for grouping
Shared character: a feature that all members in the group have in common
Derived character: a feature that evolved only within the group under consideration

7. Cladistics
Clad: used to describe a group of organisms that includes an ancestor and all of its descendants
Cladogram: Diagram
Molecular Cladistics: looks at derived amino acids at each position in a protein

8. Three Domains of Life Domain Bacteria Prokaryotic Single-celled
Have a cell wall
Heterotrophic and autotrophic
Ex: bacteria

9. Three Domains of Life Domain Archaea Prokaryotic
Most live in harsh environments
Have cell walls
Unicellular
Heterotrophic and autotrophic

10. Three Domains of Life Domain Eukarya Have eukaryotic cells
Includes kingdoms plants, animals, fungi, and protists

11. Domain Eukarya Kingdom Protista Eukaryotic
Not plants, animals or fungi
Most are unicellular
Some multicellular but lack tissue organization
Autotrophic or heterotrophic

12. Domain Eukarya Kingdom Fungi Eukaryotic Heterotrophic
Unicellular and multicellular
Absorb their food through extracellular digestion

13. Domain Eukarya Kingdom Plantae Eukaryotic Muclticellular
Most are autorophic

14. Domain Eukarya Kingdom Animalia Eukaryotic Multicellular Heterotrophic
Develop from embryos