Chapter7-The Classification
                 of Living Things

7-1 Classification
 
 

taxonomy - branch of biology
              - deals with classification
              - deals with naming

unity of life - all organisms are basically
                   alike in the life functions they
                   perform

diversity of life - great variety in how these
                   functions are performed

CLASSIFICATION SYSTEMS
• needed to study the variety of life in an organized, systematic way (standard)
• based on organisms' similarities of:
•  structure
•  fossil record (evolutionary history)
•  genetic make up
•  life-cycle characteristics
•  embryonic development
•  biochemical
• groupings based on evolution--present life developed from earlier forms

 
CLASSIFICATION CATEGORIES
• the categories are as follows starting with the most general and leading to the more specific category:
• kingdom
• phylum
• class
• order
• family
• genus
• species

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7-2 Major Taxonomic Groups
• scientists have not agreed on how many kingdoms there should be
• we will be using the 5 kingdom system
• the following table gives a few examples of the phyla in each kingdom of the current system

kingdom - the broadest classification category

phylum - (plural, phyla) each kingdom is
           separated into these major groups

class - related orders

order - related families

family - related genera

genus - (plural, genera) the first word (which is always capitalized) in the binomial naming system, e.g. "Homo" in the name "Homo sapien"

species - (plural, species) the second word
       (which is NOT capitalized) in the
       binomial naming system, e.g.
       "sapien" in the name "Homo sapien"

( Mnemonic: King Philip Counted Out Five Golden Slippers)

NAMING SYSTEM
(binomial nomenclature)
-two Latin words, usually italicized
-system developed by Linnaeus

e.g. Felis leo and Felis tigris
   --same genus, different species

REPRSENTATIVE ORGANISMS
-organisms studied in detail in Regents Biology

ameba

• KINGDOM = PROTISTS
• Phylum = Protozoa
• for structure see Fig. 7-15 p.137 [Tiger Book]
• unicellular
• transparent
• constantly changes shape
• animal-like nutrition

• KINGDOM = PROTISTS
• Phylum = Protozoa
• for structure see Fig. 7-16 p.138 [Tiger Book]
• unicellular
• slipperlike shape
• animal-like nutrition

• KINGDOM = ANIMALS
• Phylum = Coelenterates
• for structure see Fig. 7-17 p.138 [Tiger Book]
• multicellular
• body wall has two cell layers
• hollow body cavity with one opening
• radial symetry

• KINGDOM = ANIMALS
• Phylum = Annelids
• for structure see Fig. 7-18 p.138 [Tiger Book]
• multicellular
• segmented body
• tube-within-a-tube body structure
• openings at both ends

• KINGDOM = ANIMALS
• Phylum = Arthropods
• for structure see Fig. 7-19 p.139 [Tiger Book]
• multicellular
• segmented body
• jointed appendages
• exoskeleton

• KINGDOM = ANIMALS
• Phylum = Chordates
• Subphylum = vertebrates
• dorsal nerve cord
• true backbone
• nourish young with milk
• bodies covered with hair
• well developed brains