1. Chapter 18

2.  Why Classify? ◦ Scientists classify organisms into groups in a logical manner to make it easier to study the diversity of life. ◦ Taxonomy: The discipline of classifying organisms and assigning each a universally accepted name.  Assigning Scientific Names ◦ Each species has been assigned a name for classification purposes. ◦ Binomial Nomenclature: The two part scientific naming system used in classification.  The fist name is always capitalized and represents the Genus of the animal.  Genus: A group of closely related animals, for example; bears  The second name is specific to that type of animal.

3.  Carolus Linnaeus: Developed binomial nomenclature.  Linnaeus’s hierarchical system of classification includes seven levels.  The seven layers from smallest to larges are as follows. ◦ Taxon: A group or level of organization into which organisms are classified.  Species  Genus  Family  Order  Class  Phylum  Kingdom.  Linnaeus grouped organisms based on physical similarities and he only had two kingdoms; Animalia & Plantae.

4.  Species: A group of similar organisms that can breed and produce fertile offspring.  Genus: A group of closely related species.  Family: A group of genera that share many characteristics.  Order: A group of similar families.  Class: A group of similar orders.  Phylum: A group of closely related classes.  Kingdom: Large taxonomic group, consisting of closely related phyla.

6.  Dichotomous Key: A key used to identify a plant or animal in which each stage presents descriptions of two distinguishing characters, with a direction to another stage in the key, until the species is identified.

7.  Phylogeny: The study of evolutionary relationships among animals.  Evolutionary Classification: The strategy of grouping organisms together based on their evolutionary history.  Biologist group organisms based on evolutionary descent or phylogeny, not just physical characteristics.  Derived characters: Characteristics that show up in recent organism lineage but not in older organisms.  Cladogram: A diagram that shows evolutionary relationships.

8.  There are six (6) kingdoms in modern classification; Eubacteria, Archaebacteria, Protista, Fungi, Plantae, and Animalia.  The Three-Domain System: ◦ Modern Biologist have created a new taxonomic category called domain. ◦ Domain: is a more inclusive category and is larger than a kingdom. ◦ There are three domains: Eukarya, Bacteria, and Archaea.

9.  Eukarya: Eukaryotic, complex, maybe multi- cellular. ◦ Kingdoms: Protista, Fungi, Plantae, Animalia  Bacteria: Unicellular, prokaryotic ◦ Kingdom: Eubacteria  Archaea: Unicellular, prokaryotic, live in extreme environments. ◦ Kingdom: Archaebacteria

10. Classification of Living Things DomainBacteriaArchaebacteriaEukarya KingdomEubacteriaArchaebacteriaProtistaFungiPlantaeAnimalia Cell TypeProkaryotic Eukaryotic Cell NumberUnicellular Mostly Unicellular Some Multicellular Mostly Multcellular Some Unicellular Multicellular Mode of Nutrition Autotroph & Heterotroph Autotroph & Heterotroph Autotroph & Heterotroph AutotrophHeterotroph ExamplesE. Coli Streptococcus Methanogens Halophiles Amoeba Paramecium Mold Mushrooms Yeast Mosses Ferns Sponges Mammals Fish