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Classification Focus ?? Using information from class, do you believe the classification system will remain the same? WHY or WHY NOT?? Classification: A way to organize objects or group objects in a logical manner according to their characteristics and evolutionary history. Grouping similar objects together Ex. Grocery store – fruit, meat, cereal are grouped Shoe dept. – sneakers: running, cross training, basketball etc… Reasons to classify: Universal Easier to find Provide information about the organism Avoid mistakes Taxonomy study of classification Taxonomists: Scientists who classify organisms: Taxonomists: Aristotle – 3 main groups: air, land, water, he also grouped plants into three categories, based on differences in their stems. Taxonomists: Linnaeus: developed 7 levels of classification grouped organisms into hierarchical categories used an organism’s morphology: its form and structure, to categorize Linnaeus Cont.: Linnaeus’s categorization scheme used a hierarchy. Seven levels of organization, each more specific than the last, allowed organisms to be grouped with similar organisms. Linnaeus’ Classification Sys. Modern day classification system: Uses 7 taxonomic categories ( developed by Linnaeus): Each level is called a Taxon The levels are: 1. 2. 3. 4. 5. 6. 7. Kingdom – largest category Phylum Class Order Family Genus – a group of similar species Species – most specific category, Species: Might tell: 1. What it looks like 2. How it tastes or smells 3. Where it’s found 4. Who discovered it STOP!!! CK POINT!! Topic: Intro to Classification Date: 4-20-09 1. What is the goal of classifying organisms? 2. Who the 2 taxonomists who are given credit for shaping taxonomy and classifying organisms? 3. What did each taxonomist contribute to the classification system? In your packet: Turn to page 121-122 in the packet Get a whale text book, ch.17 Begin answering questions DO NOT FORGET HMWK DUE WED!!!! Binomial Nomenclature: 2 word naming system (scientific name) Latin, same in every language…universal 1st word – genus: identifies a group, capitalized 2nd word – species: share characteristics and reproduce among one another producing fertile offspring Both are underlined or italicized Ex. 1. Acer rubrum Maple Red = red maple tree 2. Acer saccharum Maple sugar = sugar maple trees Phylogenic tree: To classify organisms, modern taxonomists consider the phylogeny (fie-LAHJ-uh-nee), or evolutionary history, of the organism Shows the evolutionary relationships among organisms Based on several lines of evidence Fossil record may provide the basis/framework of a phylogenic tree Modern Classification System Evolutionary Classification: Grouping organisms based on evolutionary descent or common ancestors Not limited to physical similarities Show relationships based on genetic similarities Taxonomists use: 1. Homologous structures – similar structures, similar development, function is different Ex. Bird wing and the human arm Taxonomists use: 2. Analogous structures – structures appear similar, function similar, different development Ex. Bird wing and the wing of a butterfly Cladogram: diagram that shows evolutionary relationships among organisms based on shared derived characteristics a type of tree showing evolutionary relationships begin at the bottom and move up the further away from a common ancestor, the more different their genes derived character –ADD TO NOTES Cladistics uses certain features called shared derived characters, a feature that apparently evolved only within the group under consideration. Modern Classification System Cont. Separated into 3 Domains: 1. Bacteria- Eubacteria 2. Archaea - Archaebacteria 3. Eukarya (eukaryotes) - includes protests, fungi, plants, and animals 3 domains: are separates into 6 kingdoms: 1. 2. 3. 4. 5. 6. Archaebacteria Eubacteria Protists Fungus Plant Animal Vertebrates Invertebrates Organism are placed into kingdoms… Organism are placed into kingdoms… Divided by the following characteristics: Presence of nucleus Single or multi celled Ability to make own food Ability to move Kingdom 1. Arachaebacteria: : Unicellular Some movement Some make own food = Some obtain food from environment = No nucleus present Live in hostile environment like Heat, pH Kingdom: 2. Eubacteria: Unicellular Some movement Some make own food = Some obtain from environment = No nucleus present Bacilli (rod), cocci (spherical), spirilla (spiral) 3. Protista: Unicellular or multi-cellular some move some make own food some obtain food from environment contain a nucleus 4. Fungi Some are Unicellular Most are multi-cellular Do not move All fungus obtain food from environment = 5. Plants Multi-cellular Do not move Make own food = 2 types: 1. 2. Tracheophytes Bryophyte Bryophytes No true roots, No true leaves No true stems No vascular tissue ex. mosses Tracheophytes true roots, True leaves, True stems have vascular tissue 6. Animal Multi-cellular Move Obtain food from environment Organisms in each kingdom are then classified into the remaining 6 Levels: Kingdom, phylum, class, order, family, genus, specie Dichotomous Keys: Also called a field guide, & taxonomic key Use descriptions about external features to help identify the name of the organism Arranged with 2 statements describing the organism Dichotomous Keys Cont: Using the key gives you the binomial nomenclature (2 word name): genus and specie of the organism Identifies specific organisms 1a. Bean round 1b. Bean elliptical or oblong 2a. Bean white 2b. Bean has dark pigments 3a. Bean evenly pigmented 3b. Bean pigmentation mottled 4a. Bean black 4b. Bean reddish-brown Garbanzo bean Go to 2 White northern Go to 3 Go to 4 Pinto bean Black bean Kidney bean