Name ________________________________
Chapter 18 (pg 336 – 353)
Biology
CLASSIFICATION
ORIGINS OF LIFE
Life on earth is thought to have as
Approximately 1 billion years ago, through the process of ___________________,
increasingly complex multicellular organisms (many-celled)
HISTORY OF EVOLUTION
During the constant process of change in living things, some characteristics
As a result, earth is populated
HISTORY OF CLASSIFICATION
o There are ________________________ known species of organisms.
o This is
o To study so many life-forms,
WHAT IS CLASSIFICATION?
o CLASSIFICATION:
o Classification is also known as ____________________.
o ____________________ are scientists that
BENEFITS OF CLASSIFYING
o __________________________________________ names organisms.
o Prevents ______________________ such as starfish and jellyfish that aren’t
really fish.
o
Uses
History of taxonomy
HISTORY OF TAXONOMY
o The first classification system
o Aristotle divided organisms into
o Subdivided them by their habitat
 Land

 Air-dwellers
o As more and more organisms began to be discovered,
o Also, scientists did not use a universally accepted method for
o Some used common names, others used long and complex
o Common names did not always
o Example:
HISTORY OF TAXONOMY cont.
o Also, common names can vary
o Example:
CAROLUS LINNAEUS (
)
o 18th Century Swedish
o Classified organisms
o Developed
o Linnaeus classified animals based on
o Example:
o Called the
o Developed the modern system of naming known as _______________________.
o Used classification groups called _______________________________
o Used Two-word name (___________________)
o Binomial nomenclature used _____________________________
o ___________________ or ______________________
o Italicized in print
o Capitalize genus, but NOT species.
o Underline when writing
LEVELS OF CLASSIFICATION
LEVELS OF CLASSIFICATION
o ____________________ (taxa-plural) is a
o There is a ________________________ of groups (___________) from broadest
to most specific.
o Domain
o
o
o
o
o
o
o
Species
o Keep P__________ C_________ Or F___________ G______ Sick!
MODERN PHYLOGENETIC TAXONOMY
Today, modern Taxonomists use different approaches to place an organism in the correct
taxonomic group.
o
o
o
o
o
o
MODERN PHYLOGENETIC TAXONOMY cont.
o Unlike Linnaeus, Darwin, an evolutionist, made an extremely important observation
about classification:
o Organisms are classified together because they are similar;
Modern taxonomists construct a ______________________ or family tree.
The tree is used to show the __________________ _____________________
between different group of organisms.
CLADISTICS
A relatively new system of phylogenetic classification is called ________________.
o _______________________________Certain features that evolved only within
the group being studied
o Example:
CLADISTICS cont.
o In this approach, a scientist closely analyzes the evolutionary relationships
between organisms and constructs a diagram called a _________________.
MODERN PHYLOGENETIC TAXONOMY cont.
Old five kingdom system:
o
o
o
o
o
o ______________ include all __________________, which are all unicellular life
forms that lack a true nucleus.
o __________, _____________, ______________, ___________ include all
eukaryotic organisms, which are all life forms that do contain a true nucleus and
various organelles.
MODERN SYSTEM OF CLASSIFICATION
The Three Domain Modern System:
o Three Domain System:
o ______________, ______________, and _____________
o Further classified into Six Kingdoms:
1
2
3
4
5
6
DOMAINS
o Broadest
o Three domains.
o ____________________ and _______________ are
o Eukarya
Domain: ARCHAEA
o Kingdom - _______________________________
o Probably the ____________________________________.
o Live in _________________ environments.
o Found in:
o ______________________________________ (Methanogens)
o ______________________________________ (Thermophiles)
o ___________________________________ (Dead Sea; Great Salt Lake)Halophiles.
o CHEMOSYNTHESIS:
Domain: BACTERIA
Kingdom - _______________________________
o Some ____________________________________.
o Found in _______________________ except
o Important decomposers for environment.
o Commercially important in
DOMAIN EUKARYA IS DIVIDED INTO KINGDOMS:
o 1____________________________
o 2____________________________
o 3____________________________
o 4____________________________
DOMAIN EUKARYA
Kingdom: _______________________
o Most are __________________________
o Some are ____________________________
o Some are
o Aquatic
DOMAIN EUKARYA
Kingdom: _______________________
o Absorptive heterotrophs
o Cell walls
PLANTAE
o
o _________________________ (except for carnivorous plants)
o Absorb ____________________ to make glucose - __________________
o Cell walls made of
DOMAIN EUKARYA
Kingdom: _______________________
o ____________________________
o ___________________________________ (consume food and digest it inside
their bodies)
o Feed on
USE THE CHART TO DOUBLE CHECK WHAT YOU FILLED IN ON YOUR CHART IN
YOUR GROUPS…MAKE ANY CORRECTIONS THAT YOU NEED TO AT THIS TIME.
Dichotomous key
Biologists have developed a precise method to help them _______________ and
___________________ unknown organisms.
The classification tool called a _________________
o Used to
o Characteristics
o Read both characteristics and either go to another set of characteristics OR
identify the organism
Dichotomous Key Example:
1a Tentacles present – Go to 2
1b Tentacles absent – Go to 3
2a Eight Tentacles – Octopus
2b More than 8 tentacles – 3
3a Tentacles hang down – go to 4
3b Tentacles upright–Sea Anemone
4a Balloon-shaped body–Jellyfish
4b Body NOT balloon-shaped - 5
DICHOTOMOUS KEYING
o Used to
o Characteristics given in
o Read both characteristics and either go to another set of characteristics OR
identify the organism.