Classification

• Why do we need to classify species on Earth?

  To organize millions of different species
• How did our ancestors classify species?

  Based on physical appearance
• What is a limitation of using simple names for species?

  They don't indicate species relationships
• What is the Linnaean system of classification?

  A method grouping species by characteristics
• What are the main categories in the Linnaean system?

  Kingdom, phylum, class, order, family, genus, species
• Why are the names in the Linnaean system mostly in Latin?

  To make it usable across different countries
• What is the binomial naming system proposed by Linnaeus?

  A system naming species by genus and species
• How should species names be formatted in writing?

  Italicized with capitalized genus first
• What did Carl Woese propose in the 1990s?

  The three domain system of classification
• What are the three domains introduced by Woese?

  Eukaryota, bacteria, archaea
• What does the domain Eukaryota include?

  Organisms with eukaryotic cells
• What are bacteria?

  Single-celled prokaryotic organisms
• What distinguishes archaea from bacteria?

  Archaea are found in extreme conditions
• What do evolutionary trees show?

  Evolutionary relationships between species
• How are birds related to Tyrannosaurus rex according to evolutionary trees?

  They share a more recent common ancestor
• What does a split in an evolutionary tree represent?

  A common ancestor splitting into species
• What methods do scientists use to learn about species relationships?

  Comparing structure and DNA of species
• What is a mnemonic?

  A phrase to help remember lists
• What mnemonic can help remember the order of classification groups?

  Dear Kate Please Come Over For Great Spaghetti
• What are the steps in the Linnaean classification system?

  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• What are the characteristics of the three domains proposed by Woese?

  • Eukaryota: Eukaryotic cells (plants, fungi, animals)
  • Bacteria: Single-celled prokaryotic organisms
  • Archaea: Prokaryotic cells in extreme conditions
• How do evolutionary trees differ in representation?

  • They can show the same information differently
  • Splits indicate common ancestors
  • Different trees can illustrate various relationships