Biology
Chapter 3
Classification
3.1 Why Things are Grouped
Why Things are Grouped
 Classify: group
things together
based on
similarities
Classifying in Everyday Life
 What things do we
classify?
How Grouping Helps Us
 Easier to find
 Share traits (feature
that a thing has)
 Faster
Biology
Chapter 3
Classification
3.2 Methods of Classification
Early Classification
 Aristotle (Greek,
lived about 2000
years ago)
 First to classify
living things
 All living thing into
two groups
Plants
 herbs- small, soft
stems
 shrubs- medium
size, many trunks
 trees- tall, one trunk
Animals
 live in water
 live on land
 live in air
Problems with this plan



some living things
fit into more than
one group
some living things
change groups as
they grow and
develop
Used until 1700’s
The Beginnings of Modern
Classification
 Carolus Linnaeus
(Swedish, 1735)
 Classified plants and
animals into more
groups
 Based system on
specific traits
 Gave name to
organisms that
described their trait2 part name
Seven Classification Groups
kingdom-
king
phylum-
Phillip
class-
came
order-
over
familygenusspecies-
from
Germany
swimming
Two word names are genus and
species
People are
Homo sapiens
Biology
Chapter 3
Classification
3.3 How Scientists Classify Things
Classify Based on How
Organisms Are Related
 The more closely
related organisms
are the more groups
they share
 Compare cat, lion,
deer, and octopus
Tables 3-2 through
3-5 p. 56-57
Classification Chart
Kingdom:
Phylum:
Class:
Order:
Family:
Genus:
Species:
House Cat
Animalia
Chordata
Mammalia
Carnivora
Felidae
Felis
Felis catus
Dog
Animalia
Chordata
Mammalia
Carnivora
Canidae
Canis
Canis familiaris
Other Evidence Used in
Classifying
 Evolutionary history
 The ancestors that
organisms share
 Similar body
structures
Other Evidence Used in
Classifying
Body Chemistry
 How similar are
proteins (blood)
 How similar is DNA
(DNA fingerprinting)
Scientific Names Came From
Classification
Scientific namesGenus species
 Designed by
Linnaeus
 Genus- always
capitalized
 species- always
lower case
 In Latin so italics or
underline
Scientific Names Came From
Classification
 Sometimes
scientific names
sound like common
names
 Gorilla gorilla
 Giraffa
camelopadalis
Why Scientific Names Are Used
 No mistakes
 Common names occur
for more than one type
of organism, hawks Fig.
3-9 p. 60
 Scientific names
seldom change
 Scientific names are
written in the same
language (Latin)
Classification of Kingdoms
 Two kingdoms- Aristotle and Linnaeus
had plants and animals
 Then 3 kingdoms- plants, animals, and
protists
 Then 5 kingdoms, plants, animals,
protists, fungi, and monerans (bacteria)
 Now 6 kingdoms (started in 2000, not in
your textbook)
Archaebacteria
(formerly Moneran)
 Live in extreme




environments- hot,
salt
No nucleus or
other cell parts
One celled
Unique cell wall
and membrane
Unique cell
processes
Eubacteria
(formerly Moneran)
 No nucleus or other
cell parts
 One celled
 More common
bacteria
 Live in many places
Protists
 Mostly one celled, some




are many celled
Nucleus and other cell
parts
Some like plants (algae:
producers)
Some like animals
(protozoans:
consumers)
Some like fungi
(decomposers)
Fungi
 Have nucleus and
other cell parts
 Multicellular except
yeast
 Have cell walls
 Decomposers
(absorb food)
Plants
 Nucleus and other
cell parts
 Multicellular
 Have chlorophyll for
photosynthesis
 Have cell wall (don’t
move)
Animals
 Nucleus and other
cell parts
 Multicellular
 Eat- consumers
 Move from place to
place
Classification Changes
 Classification
changes as we learn
more about
organisms and their
relationship to each
other.