1. Classification of Organisms
Chapter 17

2. Biodiversity
The variety of organisms considered at all levels of populations to ecosystems.
Biologists have classified almost 2 million species
More remain unidentified
www2.warwick.ac.uk/ about/environment/faqs/

3. Taxonomy The science of describing, naming, and classifying organisms
A particular group within a taxonomic system is called a taxon
Scientist have created taxonomic systems with different numbers and levels, as well as different names.
Taxonomy.html

4. Taxonomy continued
Aristotle classified organisms into 2 groups – plants or animals.
This was inadequate because more and more organisms are found and described.
Based upon if they lived on land, in water or in the air for animals and the stems for plants.
Don’t use common names as they can vary or be misleading- ex. jellyfish

5. The Linnaean System
The system of grouping organisms into hierarchical categories according to their form and structure.
Each category represents a level or grouping from larger, more general categories to smaller, more specific categories.
Carolous Linnaeus ( )
Originally had 7 levels

6. Levels of Classification
Modern version of Linnaeus’s system uses 8 levels: (see page 338)
1. Domain
2. Kingdom
3. Phylum
4. Class
5. Order
6. Family
7. Genus
8. Species

7. Binomial Nomenclature
System of two-part names. The genus name followed by the species identifier.
The species name is written in Italics with the genus name capitalized
Species names generally come from Latin roots
Subspecies – variations of a species that live in different geographic areas
Example of subspecies- box turtle
Terrapene carolina triunui

8. Binomial Nomenclature (examples)
Homo sapiens
Chaos chaos
The species name or scientific name is written in italics with the genus name capitalized

9. Systematics
Modern biologists use this to classify organisms not only by visible similarities, but also similarities in embryos, chromosomes, proteins, and DNA. The goal is to classify organisms in terms of their natural relationships

10. Phylogenetics
The analysis of the evolutionary or ancestral relationships among taxa.
Systematists usually use several types of evidence to hypothesize about polygenetics.
Use phylogenetic diagram
Phylogeny is the evolutionary history of a species or a taxon.

11. Cladistics
A system of phylogenetic analysis that used shared and derived characters as the only criteria for grouping taxa

12. Three Domains of Life

13. Three Domains of Life Domain Bacteria Domain Archaea Domain Eukarya
Small, single-celled prokaryotic organisms
Prokaryotes, live in harsh places, has distinctive cell membranes
Eukaryotic organisms, large cells with true nucleus and complex organelles
Ex. Cyanobacteria & Hetrotrophic bacteria
Ex. Halophiles and Thermophiles
Ex. Everything else: plants, animals, etc.
Domain Bacteria- have cell wall, plasma membrane, cytoplasm that lacks complex organelles, at least 1 circular chromosome

14. Six Kingdoms Eubacteria Arachaebacteria Protista Fungi Plantae
Animalia
See page 349