Chapter 18 Taxonomy- branch of biology that groups

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Chapter 18Taxonomy- branch of biology that
groups names organisms

• Earth is home to millions of different kinds of
  organisms.
• Each of these organisms share some common
  features with every organism
• To help understand and organize information about
  living things, scientists have created a system
  for classifying them into groups.

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• The Greek philosopher, Aristotle, developed the
  first method of classification
• He divided everything into 2 groups
• Plants- herbs, shrubs, trees
• Animals- aquatic, terrestrial, aerial
• However, his system did not work. Why?

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How Organisms are Classified Today
The 8 Taxa

• Organisms are grouped into a series of categories
  called taxa, each one larger than the previous
  one.
• As you move down the list, each level becomes
  more specific includes fewer members than the
  level above it.

1. Domain 2. Kingdom
3. Phylum 4. Class
5. Order 6. Family
7. Genus 8. Species
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Classification of the Domestic Dog
Kingdom Animal Dog, human, insect, worm, any animals
Phylum Chordata Dog, human, fish, other backboned animals
Class Order Mammal Carnivora Dog, human, whale, all other mammals Dog, wolf, lion, bear
Family Canidae Dog, wolf, fox
Genus Canis Dog, wolf
Species familiaris Dog
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Binomial Nomenclature- 2 part naming system

• In the 1700s, Swedish botanis Carolus Linnaeus
  created the binomial nomenclature naming system
  still used today
• It gives each kind of organism a two-part name,
  the first part of an organisms name identifies
  the genus
• The second part of the name identifies the
  species

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Domains Kingdoms
Domains Kingdoms Characteristics
Bacteria Eubacteria Single-celled prokaryotes oldest organisms on Earth
Archaea Archaebacteria Single-celled dont have peptidoglycan in cell walls
Eukarya Protist, Fungi, Plant, Animal All are eukaryotes
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Domain Eukarya
Kingdom Cell number Cell characteristics Organisms
Protist Single or Multi Cells have a nucleus Algae, protozoa
Fungi Single or multi Cells have a wall nucleus no chloroplasts Yeast mushrooms
Plants Multi Cells have a wall, nucleus chloroplasts Moss, ferns, trees, flowering plants
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Domain Eukarya
Animals Multi Cells have a nucleus, but no wall or chloroplasts Sponges, worms, insects, mammals, fish, amphibians, reptiles birds