310 likes | 459 Views
BioEd Online. Diversity of Life: Introduction to Biological Classification. By Deanne Erdmann, MS. BioEd Online. Why Do We Classify Organisms?. Biologists group organisms to represent similarities and proposed relationships.
E N D
BioEd Online Diversity of Life: Introduction to Biological Classification By Deanne Erdmann, MS
BioEd Online Why Do We Classify Organisms? • Biologists group organisms to represent similarities and proposed relationships. • Classification systems change with expanding knowledge about new and well-known organisms. Tacitus bellus
History of the Kingdom System • http://earthlingnature.wordpress.com/2011/12/05/a-brief-history-of-the-kingdoms-of-life/
BioEd Online Classification • Binomial Nomenclature • Two part name (Genus, species) • Hierarchical Classification • Seven Taxonomic Categories • Systematics • Study of the evolution of biological diversity Leucaena leucocephala Lead tree
BioEd Online Binomial Nomenclature • Carolus von Linnaeus • Two-word naming system • Genus • Noun, Capitalized, Underlined or Italicized • Species • Descriptive, Lower Case, Underlined or Italicized Carolus von Linnaeus(1707-1778) Swedish scientist who laid the foundation for modern taxonomy
BioEd Online Hierarchical Classification • Taxonomic categories • Kingdom King • Phylum Philip • Class Came • Order Over • Family For • Genus Good • Species Soup
BioEd Online Kingdoms and Domains The three-domain system Bacteria Archaea Eukarya The six-kingdom system Bacteria Archaea Protista Plantae Fungi Animalia The traditional five-kingdom system Monera Protista Plantae Fungi Animalia
BioEd Online Systematics:Evolutionary Classification of Organisms • Systematics is the study of the evolution of biological diversity, and combines data from the following areas. • Fossil record • Comparative homologies • Cladistics • Comparative sequencing of DNA/RNA among organisms • Molecular clocks
BioEd Online Taxonomic Diagrams Mammals Turtles Lizards and Snakes Crocodiles Birds Mammals Turtles Lizards and Snakes Crocodiles Birds PhylogeneticTree Cladogram
http://evolution.berkeley.edu/evolibrary/article/phylogenetics_02http://evolution.berkeley.edu/evolibrary/article/phylogenetics_02
BioEd Online Dichotomous Keys Identify Organisms • Dichotomous keys versus evolutionary classification • Dichotomous keys contain pairs of contrasting descriptions. • After each description, the key directs the user to another pair of descriptions or identifies the organism. Example: 1. a) Is the leaf simple? Go to 2 b) Is the leaf compound? Go to 3 2. a) Are margins of the leaf jagged? Go to 4 b) Are margins of the leaf smooth? Go to 5
Dichotomous key • http://www.classzone.com/cz/books/bio_09/resources/htmls/animated_biology/unit7/bio_ch21_0657_ab_tree.html
Plant Phyla • bryophyta • Filicinophyta • Coniferophyta • Angiospermophyta
Bryophyta(“bryo-”: moss) • mosses, liverworts and hornworts • stems radial symmetry (mosses) • stems bilateral symmetry (liverworts), no lignin • no true leaves or roots • no cuticle. • reproductive structure are called sporangium which are on long stalks with capsules on end. In this image the spore is released from the sporangium to develop into another plant.
Filicinophyta (ferns) • leaves • roots non woody stems • divided leaves • height up to 20 m • reproduction: sporangia (sori) contain reproductive spores
Coniferophytes (conifers and pines) • trees (100m), shrubs, • woody (lignin) stems, • waxy narrow needle like leaves. • vascular system (tracheids) • reproduction: monoecious, microsporophylls (male) non motile gametes often with air bladders for water/ air dispersal. macrosporophylls (female) ovule on cone scale
Angiospermophyta (flowering plants and grasses) • roots • stems • leaves. • vascular bundles (xylem/ phloem ) • waxy cuticle, • annual or perennial up to 100m • reproduction: • ovules in an enclosed carpel structure. • pollen grains produced from anthers • variety of pollen transfers vectors
Animal Phyla (just the invertebrates for now…) • Porifera (sponges) • Cnidaria (jellyfish…) • Platyhelminthes (flatworms) • Annelida (segmented worms) • Mollusca (snails, clams, octopus…) • Arthropoda (insects, crustaceans, spiders...)