Classification/Taxonomy
Chapter 17
Why Classify?
To study the diversity of life, biologists use a
classification system to name organisms &
group them in a logical manner.
Taxonomy
Discipline of classifying
organisms and assigning each
organism a universally
accepted name.
Defined:
In other words, naming things.
Why common names don’t work
Common names vary among languages.
Example:
United Kingdom – Buzzard refers to a hawk
United States – Buzzard refers to a vulture
Red-tailed Hawk
Honey Buzzard
Turkey Vulture
Another Example:
Dolphin
Dolphin
Tursipos truncatus
Mahi mahi
Carolus Linnaeus

(1707 – 1778)

Created the system of naming we use today.

In taxonomy, a group or level of
organization is called a taxonomic category
or taxon.
Binomial Nomenclature

“Bi” means 2

“nomial” means naming

Nomenclature means “the system of”
Defined:
In binomial nomenclature, each
species is assigned a two-part
scientific name. (Genus & species)
Example of Binomial Nomenclature
 Polar Bear is Ursus maritimus

Ursus: genus
Ursus contains 5 other kinds of bears

maritimus: species
The Latin word, maritimus, refers to the sea.
Polar bears often live on pack ice that floats in the sea.
Definitions to know
 Genus: is a group of closely related species
 Species: Group of similar organisms that can
breed and produce fertile offspring
 Family:
Group of genera that share many
characteristics
 Order:
Group of similar families
 Class:
Group of similar orders
 Phylum:
Group of closely related classes
 Kingdom:
Largest taxonomic group,
consisting of closely related
Here We Go…
Polar Bear
Species: maritimus
Genus: Ursus
Family: Ursidae
Order: Carnivora
Class: Mammalia
Phylum: Chordata
Kingdom: Animilia
Domain: Eukarya
What do these mean?...lets see
What they mean
Species: maritimus (lives in marine environment)
Genus: Ursus (kind of bear)
Family: Ursidae (larger category of bears)
Order: Carnivora (meat-eating animals)
Class: Mammalia (warm-blooded, hair, & milk)
Phylum: Chordata (vertebrates)
Kingdom: Animilia (there are 6 kingdoms)
How to remember:
Da King Phillip Came Over For Green Salad
Domain Kingdom Phylum Class Order Family Genus Species
Phylum
Chordata
Class
Mammalia
Order
Carnivora
Family
Ursidae
Genus
Ursus
Species
maritimus
The Three-Domain System

There are 3 Domains:




Domain Bacteria
Domain Archaea
Domain Eukarya
There are 6 Kingdoms:
1. Eubacteria
4. Fungi
2. Archaebacteria
5. Plantae
3. Protista
6. Animalia
The Three-Domain System

There are 3 Domains:

Domain Bacteria




Domain Archaea




Kingdom Eubacteria
Unicellular/Prokaryotes
Cell walls have Peptidoglycan
Kingdom Archaebacteria
Unicellular/Prokaryotes
Cell walls withOUT Peptidoglycan
Domain Eukarya

Kingdoms Protista, Fungi, Plantae, Animalia
Domain Archaea
Kingdom Archaebacteria
-
Unicellular Prokaryote
Cell walls withOUT Peptidoglycan
Extremophiles – Love extreme environments
like volcanoes, hydrothermal vents, and hot springs
Archaea
Hydrothermal Vent
Hot Spring
Volcano
Domain Bacteria
Kingdom Eubacteria
-
Unicellular Prokaryote
Cell walls with Peptidoglycan
All other bacteria you encounter everyday
E. coli
Staphlycoccus
Streptococcus
Domain Eukarya
Kingdom Protista
-
Video Clip: Amoeba
Unicellular or Multicellular
Live in colonies
Amoeba
Euglena
Paramecium
3 Categories of Protista
1.
Plant-like
1.
2.
2.
Animal-like
1.
2.
3.
Example: Algae
Perform photosynthesis (autotrophs)
Example: Amoeba
Can cause disease (malaria, sleeping
sickness)
Fungus-like
1.
Example: Slime molds
Plant-like Protists
Algae
Euglena
Live
in shallow water
Photosynthetic (autotrophic)
Can also be heterotrophic when
light not available
Absorb
nutrients
Ingest other organisms
Animal-like Protists
Also
called Protozoans
4 Types
1.
Ciliates (Example: Paramecium)
2.
Sarcodina (Example: Amoeba)
Zooflagellates
Sporozoans
3.
4.
Slime Mold
Domain Eukarya
-
Kingdom Fungi
Unicellular or Multicellular
Cell walls made of Chitin
Heterotrophs….they eat!
Yeast
Mushrooms
Domain Eukarya
-
Kingdom Fungi
Can reproduce sexually & asexually
-
-
Usually reproduce asexually
Yeast reproduce asexually by budding
However, under unfavorable conditions
(such as drought) fungi reproduce sexually
Kingdom Fungi
•Hyphae
•Thread-like structures which form all parts of the
fungus
•Main function is to help fungus obtain food – provide
large surface area for absorption of nutrients
Domain Eukarya
-
Kingdom Plantae
Multicellular
Cell walls made of Cellulose
Autotrophs….make their own food
Trees & Grass
Moss
Venus Fly Trap
Domain Eukarya
-
Kingdom Animalia
Multicellular
NO cell walls
Heterotrophs….they eat
Worms
Insects
Jellyfish
Giraffes
6 Kingdoms
Eubacteria
Prokaryote
Autotroph or
heterotroph
Most
common
bacteria
Archaebacteria
Prokaryote
Autotroph or
heterotroph
“Ancient Bacteria”
Protista
Fungi
Plantae
Animalia
Eukaryote
Eukaryote
Eukaryote
Eukaryote
Autotroph
Heterotroph
Autotroph/ Heterotroph
heterotroph
Includes
Algae
Cell wall w/
Peptidoglycan
Live in very
hot places
Don’t
belong in
other euk
E. ecoli
Pyrococcus furiosus
Paramecium
Release
enzymes
to digest
food
Cell walls
w/cellulose
&
Chloroplasts
H. coccinea
Fern frod
No cell wall
No
chloroplasts
Multicellular
Homo sapiens
Write Scientific Names Correctly
Genus species
 Genus capitalized
 Species lower case
 Underline if hand written
 Italics if typed

Homo sapiens
Genus
species
Canis lupis
Hippocampus erectus
Scientific Name: Genus species
If these three species belong to the same
genus, they are descended from a common
ancestor.
Felis domestica
domestica
Felis
Domestic
Cat
Felis leo
leo
Lion
Felis margarita
margarita
Sand cat`
A Problem with Traditional Classification
Example: The Crab, The barnacle, & The limpet
•
The barnacle and the limpet have similarly
shaped shells & look alike
•
The crab has a very different body form
•
Based on anatomy, the barnacle & limpet could
be classified together and the crab in a different
group.
Related
This incorrect because
crabs and barnacles
are actually related
Draw this!
Crustaceans
Gastropods
Molted Exoskeleton
Segmentation
Free swimming Larva
Even though they do
not look a like, crabs &
barnacles are actually
related
Classification Using Cladograms
Cladogram: A diagram that shows the
evolutionary relationships among a group of organisms.
Crustaceans
Gastropods
Molted Exoskeleton
Segmentation
Free swimming Larva
Using Cladograms, you can
see that crabs and barnacles
share similar characteristics
because they both molt & are
segmented
Crustaceans
Gastropods
Molted Exoskeleton
Segmentation
Free swimming Larva
You can also see that
ALL have a free
swimming larva stage
The End.