9/21/2011
Dichotomous Key
Look out for the special check mark to
know which notes to write!
On a checked slide, write all notes, unless …
Classification
On a checked slide with lots of notes, just write
underlined text!
text!
Aristotle
First man to develop a system to classify organisms
2 kingdoms
System that groups organisms based on common
features that they share
He subdivided each
kingdom
Plant
Plant-- based
division on size
Herbs
Shrubs
Trees
Animals
Animals-- based
division on habitat
Air
Land
Sea
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Animals: Air Land Sea
Carolus Linnaeus
Improved classification system
Based his grouping on physical
features
Linnaeus =Universal name=
Binomial Nomenclature
Common names are misleading
Puma
All organisms are given a universal name
Used by all scientists
Helpful when many common names are used
Cougar
A seahorse is not a
horse, but a fish.
Mountain Lion
Name is composed of 2 names
Genus name
Capitalized and comes first!
first!
Species name
lower case and comes second
Both names are underlined
Example: Tolypeutes matacus – Three Banded Armadillo
Scientific name
Myotis macrotarsus
“Mouse
“Mouse--eared bat with big feet”
Cat
Genus name= Felis
Species name=
domesticus
domesticus=house
=house cat
sylvestris
sylvestris=wildcat
=wildcat
Human
Genus name=Homo
Species=
Species=sapien
sapien
Kingdom: Animalia (mobile critters; have
many cells; can’t make their own food)
Phylum: Chordata (flexible skeletal rod with
accompanying nerves)
Class: Chondrichthyes (‘fish’ with a
cartilaginous skeleton)
Order: Lamniformes (‘Mackerel’ sharks)
Family: Lamnidae (‘Mackerel’ sharks)
Genus: Carcharodon (from the Greek carcharos
meaning “ragged” or “pointed” and odon
meaning “tooth”)
Species: carcharias (Greek for “shark”)
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Modern classification system
Reclassified
Uses Linnaeus system but adds:
comparison of body chemistry and development
features
DNA sequence
Cytochrome C
Hemoglobin
Developmental stages
of embryos
Modern Classification System
Classification
=Taxa
Domain= Eubacteria
Kingdom=
Kingdom=Eubacteria
Eubacteria
Prokaryotic Bacteria
Domain=
Domain=Archaea
Archaea
Kingdom=
Kingdom=Archaebacteria
Archaebacteria
Extreamophiles
Domain Eukarya
Contains 4 kingdoms
Kingdom=Protista
Kingdom=Fungi
Kingdom=Plant
Kingdom=Animal
Classification Taxa
Domain is the largest Taxa
Domain contains one or more
kingdoms
Domain
Groups
A Mnemonic Device:
Dear
King
Philip
Came
Over
Each division
contains fewer
organisms, but
shares more features
in common.
For
Ginger
Snaps
Classification
Which two animals are most closely related?
contain the most organisms
Each kingdom is then
subdivided into:
Phylum, Class, Order, Family,
Genus, Species
Species
contain the fewest organisms but
with the most physical features
in common
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Ways to Identify an Unknown ?
Field Guides
Domain:
Kingdom:
Phylum:
Shoe Classification
Can you classify shoes
based on their
characteristics?
Class:
Order:
Family:
Dichotomous Keys
Composed of statements with 2 opposite parts or
categories.
Choose the statement that is true about an unknown
organism.
Genus:
Species:
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