Basic Taxonomy

• Systematics


  is concerned with the classification systems and nomenclature of organisms. It is a branch of biological science that studies the distinctive characteristics of species and how they are related to other species through time.
• Taxonomy


  is a science that deals with naming, describing and classification of all living organisms
• Phylogenetic


  is the study of the evolutionary history and relationships among individuals, groups of organisms (e.g., populations, species, or higher taxa), or other biological entities with evolutionary histories (e.g., genes, biochemicals, or developmental mechanisms
• Why do scientist classify living organisms?

  To determine the following:

  1. known (and unknown) species.
  2. defining characteristics of each species.
  3. relationships between these species.
• Aristotle


  • Greek philosopher
  • classified all the animals, Historia Animalium
  • grouped creatures into hierarchy
  • "Great Chain of Being"
• Carolus Linnaeus

  • Carl von Linne
  • Swedish botanist and explorer
  • developed the Linnean system, a taxonomic classification system
  • organized organisms from larger to smaller and more specific categories, the Hierarchical System
  • created the scientific naming system, Binomial System of Nomenclature
• Binomial Nomenclature: two-part name (genus and specific epithet)
• Rules in writing the name using binomial nomenclature:

  1. the name should be in Latin;
  2. the genus of an organism begins with a capital letter; the species designation begins with a lowercase letter;
  3. the entire scientific name is italicized when typewritten or underlined when handwritten
  4. all taxa must have an author when described
• The scientific name for an organism is made from the:

  genus and species name
• Nomenclature Codes:

  1. International Code of Botanical Nomenclature (ICBN) - algae, fungi, plants
  2. International Code of Zoological Nomenclature (ICZN) - animals
  3. International Code of Nomenclature Bacteria (ICNB) - bacteria
  4. International Committee on Taxonomy of Viruses (ICTV) - viruses
• Taxonomic Hierarchy


  is the process of arranging various organisms into successive levels of the biological classification either in a decreasing or an increasing order from kingdom to species and vice versa.
• Taxonomic Hierarchy

  1. Domain
  2. Kingdom
  3. Phylum
  4. Class
  5. Order
  6. Family
  7. Genus
  8. Species
• Domain


  is the highest taxonomic rank in the hierarchical biological classification sysrem, above the kingdom level
• Kingdom


  is the next highest level of classification which is divided into subgroups at various levels. There are 5 kingdoms (others are 6) in which the living organisms are classified, namely, Animalia, Plantae, Fungi, Protista, and Monera (plus Archaea Bacteria)
• Kingdom Archaea

  • ancient bacteria
  • prokaryotes others are eukaryotes
  • unicellular
  • cells DO NOT have peptidoglycan
  • mostly extremophiles
  • halophiles, methanogens, and thermophiles
  • some are autotrophs, some are heterotrophs
  • halobacteria, methanopyrus kandleri, thermoplasma acidophilum
• Kingdom Protista

  • plant-like, animal-like, and fungus-like organisms
  • eukaryotes
  • mostly unicellular, few are colonial and multicellular
  • mostly aquatic
  • some are autotrophs, some are heterotrophs
  • euglena, amoeba, paramecium
• Kingdom Eubacteria


  • true bacteria and blue-green algae (cyanobacteria)
  • prokaryotes
  • unicellular (some form colonies and filaments)
  • cells HAVE peptidoglycan
  • survives almost anywhere
  • autotrophs, heterotrophs, or chemoautotrophs
  • cocci, baccili, and spirilla
  • some organisms in this kingdom takes inorganic chemicals and transforms it into energy
• Kingdom Fungi

  • eukaryotes
  • mostly multicellular, very few unicellular
  • all are heterotrophs
  • form spores for reproduction
  • the cell wall contains chitin
  • breaks down organic materials
  • provides drugs and aids in food production
  • "model organisms" in genetics and molecular biology
  • causes animal and plant diseases
  • rhizopus, neurospora, agaricus, fusarium
• Kingdom Plantae


  • eukaryotes
  • multicellular
  • autotrophs
  • cells are enclosed by a rigid cell wall
  • has chlorophyll
  • producers
  • have two major groups: 1. bryophytes 2. tracheophytes
• Bryophytes


  is the informal group name for mosses, liverworts and hornworts. They are non-vascular plants, which means they have no roots or vascular tissue, but instead absorb water and nutrients from the air through their surface (e.g., their leaves).
• Types of Bryophyte Plants:

  1. Haircap Moss
  2. Anthocerotophyta Hornwort
  3. Woodsy Thyme-Moss
  4. Common Liverwort
• Tracheophytes


  are vascular plants that possess, lignified water-conducting tissues. Tracheophytes have transport vessels, xylem, and phloem. Xylem transports water up from roots. Phloem transports food made during photosynthesis and nutrients to where they are needed in the plant
• Vascular plants:

  1. ferns and fern allies
  2. club mosses and whisk tails
• Kingdom Animalia


  • eukaryotes
  • multicellular
  • heterotrophs
  • consumers
  • biggest kingdom in the living world
  • has two major groups: 1. vertebrates 2. invertebrates