Biology Notes
Dr. Hensley/ Mrs. Ingram
2016
Classification
Why Classify??????
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

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Helps to group or organize living things
Easier to study
Study relationships (interactions) between groups of living things
Universal system – used by everyone
Carl Linnaeus:
“FATHER OF TAXONOMY”
o Taxonomy – Study of Taxons - Taxon = Group
o Process of grouping things or organizing things
 Linnaeus created the BINOMIAL NOMENCLATURE = Method of
naming using 2 names
o BI = TWO
o NOMIAL/NOMEN = NAMES
o CLATURE = WAY OF NAMING
o Latin
o Genus species
Dumb
Domain
Part of Modern Classification
Modern Classification has 8 taxons
Linnaeus’ Classification had 7 taxons
King
Phillip
Came
Over
For
Green
Soup
Species = members that can reproduce and produce fertile offspring
Cladograms – an upside down family tree
 “Derived characteristics” at branches of
cladogram
 Characteristic shows up in newer organisms
and not ancestors
 See crab, barnacle, limpet cladograms in textbook
Classic way of classifying: used physical characteristics
Evolutionary way of classifying: used cladograms - evolutionary
characteristics
Modern way of classifying: uses DNA (Molecular) characteristics
“Molecular Clock”
DNA
Time
To see how
long it has
been for this
evolutionary
change.
Dichotomous Key: Using 2 choices to identify an unknown species
Di = 2 parts
chotomous= to cut or divide
Key= Map
Always uses two options which are opposite from each other to
determine the organism’s identification and directs you where to go next
in the key: Such as…
1. a
b
2. a
b
3. a
b
4. a
b
Has a tail…………………………………… Go to #2
Does not have a tail………………………… Go to #3
Has fur………………………………………. Go to …etc.
Does not have fur……………………………
Has less than 4 legs………………………….
Has more than 4 legs…………………………
Has a tail……………………………………
Does not have a tail…………………………
Prokaryotes: Has NO NUCLEUS; no membrane bound organelles;
small and simple
Bacteria
Eukaryotes: Has NUCLEUS; has membrane bound organelles; more
complex and bigger
Eukaryotes
Autotrophs: Organisms that make their own food
PLANTS
Heterotrophs: Organisms that CANNOT make their
own food; they must eat food to survive - HUMANS