1. Classification of Organisms Ranny Copenhaver George Wythe High School

2. Why Classify? Because there are so many known species, a system of classification is needed for several reasons: a. Organize species into groups and discuss them. b. Identify new organisms. c. Show relationships between organisms. d. It is human nature to feel the need to organize objects.

3. Taxonomy Taxonomy is the science of classifying organisms.

5. The Binomial System 1.Although Aristotle had an early classification system, our modern system was developed by Carolus Linnaeus. 2.Each organism is given a two part name using Latin as a standard language providing a uniform means of communication for all people. This avoids the confusion caused by organisms with different common names in different areas. This is called Binomial Nomenclature (means to name using two name). –The two names come from the Genus and Species names. The format is Genus species or G. species. e.g., Castor canadensis –The Genus name is capitalized and may be abbreviated by the first initial. Species name is not capitalized and cannot be used alone. e.g., C. canadensis.

6. 1.The binomial classification system is hierarchal. The levels of organization are: kingdom phylum class order family genus species. In plants, fungi and algae phyla also called divisions. Each of these levels is called a taxon. 2. Note that the genus and species name are italicized because they are Latin. When handwriting, underline the words. Other levels are capitalized but no special print features are used. The Taxonomic Hierarchy

7. What is a species? 1.Capable of reproducing with one another. 2.Individuals of one species may appear quite dissimilar. 3.Offspring may appear different from one another. 4.Individuals from different species do not generally reproduce with one another. 5.Estimates on the number of species range from 2 and 100 million species on the planet although about 1.4 million species are currently named and described. Note that this is for eukaryotic (complex cells) species only. It is much more difficult to estimate the number of prokaryotic (primitive, simple cells) species.

8. The Six Kingdoms System 1.Originally there were only two kingdoms recognized: animals and plants. 2.Later, these two were divided into five: animals plants fungi protists bacteria. 3. Each kingdom evolved from different single-celled ancestors.

9. Most people now recognize 6 kingdoms: 1.Two prokaryotic (Kingdom Monera) - asexual reproduction (1) Archaebacteria are very ancient bacteria. (2) Eubacteria are more modern bacteria. (a) Inhabit nearly every known habitat (b) Prokaryotic (c) Consumers, producers, and decomposers (d) Some cause disease but most are harmless