Transcript Classification - Mrs. GM Biology 200

Unit 11: Classification
Ch. 3 Classification
Taxonomy = branch of biology that deals w/
naming & classifying organisms.
200
Why Things Are Classified
• What does it mean to classify?
–to group based on similarities
• Examples of classifying in everyday life…?
• Why are organisms/objects classified?
–easier to “find”
–show shared traits
–show relationships among living &
extinct species
Why Things Are Classified
• What is a dichotomous key?
– a tool used for classification
• At each step, the user is given two choices (either/or).
– Each alternative leads to another question…
» until the item is identified.
• What are two ways to make a dichotomous key?
– branching “tree” diagram
– list format
Why Things Are Classified
• How are organisms classified?
– very broad characteristics  very specific
• Based on…?
– evolutionary relationships
– What is a group of organisms called?
• taxon (plural = taxa)
– How many taxa are there?
» 8 (Domain  species)
Domain
Early Classification
• Who devised the 1st
classification system?
–Aristotle
• How did he classify
organisms?
–2 taxa
» 1. plants (by type of stem)
» 2. animals (by environment
in which they live)
According to Aristotle, which
of these 3 animals would be
classified more closely?
Beginning of Modern Classification
• Who was the “Father of Modern
Taxonomy”?
–Carolus Linnaeus
• How did he classify organisms?
–2 main groups = kingdoms
» plants
» animals
–Also used other taxa (groups) including:
» genus
~similar species
» species
~organisms w/ similar traits
Beginning of Modern Classification
• What is a
species?
– group of
organisms
capable of
mating with
one another
in nature to
produce
fertile
offspring
Beginning of Modern Classification
• How did Linnaeus name organisms?
– used binomial nomenclature
•
2 name system
–
written: Genus species or Genus species
»
»
–
Genus = 1st name, capitalized
species = 2nd name, lower case & descriptive
Ex. Common name
»
»
»
»
Humans
White Oak tree
Red Oak tree
Bottlenose dolphin
Genus & species
Homo sapiens
Quercus alba
Quercus rubra
Tursiops truncatus
Beginning of Modern Classification
• Why don’t we use
common names?
1. two organisms
can have same
common name,
but not sci. name
2. scientific names
rarely change
3. scientific names
are written in
same language
around the world
How Scientists Classify Today
• What do current classification systems reflect?
– relationships
• based on evolutionary ancestry
• Ex. According to the phylogenetic tree on the
right, who are humans most closely related to?
How Scientists Classify Today
• Can classification systems change?
– Yes.
• Why?
– With scientific advancements, we gain new data &
learn more about organisms…
How Scientists Classify Today
• Classification systems we’re going to discuss:
– 5 Kingdom system
• Monera, Protista, Fungi, Plantae, Animalia
– 6 Kingdom system
• Monera split into Archaebacteria & Eubacteria… other 4
kingdoms (Protista, Fungi, Plantae, Animalia) stay same
– 3 Domain system
• Archaea, Bacteria, Eukaryota (Eukarya)
– 4 kingdoms (Protista, Fungi, Plantae, Animalia) grouped in Eukaryota
How Scientists Classify Today
• Trick to help you remember
major classification groups
in the domain system…
•
•
•
•
•
•
•
•
Did
Katy
Perry
Come
Over
For
Good
Sushi?
 Domain
 Kingdom
 Phylum
 Class
 Order
 Family
 Genus
 species
Where would Domain belong
in this diagram?
How Scientists Classify Today
• What is the
relationship
among the levels?
– from Domain
down, each level
has a new set of
criteria that must
be shared
– Organisms that
are more closely
related  share…
• more levels
DOMAIN
Eukaryota
Once an organism shares a more specific taxon
(lower group) it MUST share the more unifying
taxa (higher groups)
How many levels of
classification do we
share with dolphins?
How Scientists Classify Today
• When using the 5 or 6
Kingdom system…
– Which group is largest &
most inclusive?
• Kingdom
– Which is smallest & least
inclusive?
• species
How Scientists Classify Today
• When using the 3
Domain system…
Domain
– Which group is largest &
most inclusive?
– domain
– Which group is smallest
& least inclusive?
– species
Domain
Eukaryota
Domain: Archaea
6 Kingdom system: Archaebacteria
5 Kingdom system: Monera
• prokaryotic
• unicellular
• feeding
– heterotrophic or autotrophic
• other characteristics
– older, less complex bacteria
– live in extreme environments
• examples
– bacteria:
• in salt lakes
• at hydrothermal vents
Domain: Bacteria
6 Kingdom system: Eubacteria
5 Kingdom system: Monera
• prokaryotic
• unicellular
• feeding
– heterotrophic or autotrophic
• other characteristics
Staphylococcus
– modern, more complex bacteria
• evolved from Archaea
– most common & very diverse
– free-living or pathogenic
• examples
– Staphylococcus
– E. coli
– cyanobacteria
cyanobacteria
Domain: Eukaryota
• All are eukaryotic
• 4 of the 5 (or 6) kingdoms
– 1. Protista
– 2. Fungi
– 3. Plantae
– 4. Animalia
Domain: Eukaryota
1. Kingdom: Protista
Amoeba
• eukaryotic
• mostly unicellular
• feeding
– heterotrophic or autotrophic
• other characteristics
– can be plant-like, animallike, or fungus-like
Paramecium
• examples
–
–
–
–
Amoeba
Paramecium
Euglena
algae
algae
Euglena
Domain: Eukaryota
2. Kingdom: Fungi
• eukaryotic
• multicellular***
• feeding
– heterotrophic
• digest food outside & absorb nutrients
• other characteristics
– cell walls made of chitin
– decomposers & parasites
• examples
– mushrooms
– molds
– yeast (*** unicellular)
• eukaryotic
• multicellular
• feeding
Domain: Eukaryota
3. Kingdom: Plantae
– autotrophic
• photosynthesis
• other characteristics
– cell walls made of cellulose
– produce oxygen
• examples
–
–
–
–
–
mosses
ferns
grasses
shrubs
trees
Domain: Eukaryota
4. Kingdom: Animalia
• eukaryotic
• multicellular
• feeding
– heterotrophic
• other characteristics
– no cell wall
• examples
– invertebrates
•
•
•
•
insects
worms
sponges
corals
– vertebrates
•
•
•
•
•
fish
birds
amphibians
reptiles
mammals
Links
•
•
•
•
http://www.brainpop.com/science/diversityoflife/classification/preview.weml
http://anthro.palomar.edu/animal/default.htm
http://www.ruf.rice.edu/~bioslabs/studies/invertebrates/kingdoms.html
http://www.nclark.net/Classification