Science - Domains

• Biological classification


  A system used by scientists to describe organisms, or living things. Also known as scientific classification or taxonomy.
• Classify


  To place living things in different categories, or groups, based on the features they share
• Levels of groups in the classification system


  • Highest-level groups (largest and most general)
  • Smaller groups of similar organisms
  • Even smaller groups with even more similar features
• Genera (genuses)


  The next-to-lowest groups in the classification system, containing organisms that are very closely related
• Species


  The lowest-level groups, where members have many common traits and can produce offspring of the same species
• The Six-Kingdom System


  • Archaea
  • Bacteria
  • Protista
  • Fungi
  • Plantae
  • Animalia
• Archaea


  The only kingdom in the Archaea domain, single-celled organisms that evolved separately from true bacteria
• Bacteria


  The only kingdom in the Bacteria domain, true bacteria that live in almost every environment
• Kingdoms in the Eukarya domain


  • Protista
  • Fungi
  • Plantae
  • Animalia
• Protista


  Most protists are single cells, including algae and protozoans
• Fungi


  Have many cells arranged in threadlike groups, including mushrooms, yeasts, and molds
• Plantae


  Plants are made of many cells, most are green or have green parts
• Animalia


  Animals have many cells, move around easily and quickly react to their surroundings
• Domains


  • Archaea
  • Bacteria
  • Eukarya
• Archaea domain


  Single-celled organisms that evolved separately from true bacteria, many live in extreme environments
• Bacteria domain


  True bacteria that live in almost every environment, some can cause diseases
• Eukarya domain


  Organisms with a nucleus in their cells, divided into four kingdoms: Protista, Fungi, Plantae, and Animalia
• Biological classification lets scientists give an exact name to every species
• Scientific name


  Made up of two Latin words: the first is the genus name, the second is the species name
• Carolus Linnaeus is considered the 'Father of Taxonomy' for developing the modern taxonomic classification system in the 1700s
• Linnaeus' two most important contributions to taxonomy

  • A hierarchical classification system
  • The system of binomial nomenclature (a 2-part naming method)
• The modern taxonomic classification system has eight main levels

  • Domain
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• The 7 classifications of humans

  • Kingdom - Animalia
  • Phylum - Chordata
  • Class - Mammalia
  • Order - Primates
  • Family - Hominidae
  • Subfamily - Hominidae
  • Genus - Homo
• Characteristics used by biologists to organize species into a taxonomy tree


  • Physical appearance
  • Method of movement
  • Reproduction
  • Habitat
  • What and how they eat
  • Hereditary information
  • Internal structures (vertebrates vs. invertebrates)
• Dichotomous key


  A series of 'yes' and 'no' responses that address the presence or absence of a single trait, used to create classifications