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Chapter 17
Organizing Life’s Diversity
Classification
Classification
• Classification: The grouping of objects or information
based on similarities.
• Taxonomy: the branch of biology that groups and
names organisms based on their different
characteristics.
Carolus Linnaeus 1707-1778
• Swedish botanist famous for his work in
Taxonomy.
• “Father of Taxonomy”
Why taxonomy?
• By grouping living things into defined
hierarchies and giving them individual names
we create order which allows us more easily
to study the seemingly chaotic world of
nature.
Taxonomy
• Hierarchical system involving successive levels.
• Each group at any level is called a taxon
• Highest level = Domain. All life belongs to one of 3 domains (Bacteria,
Archaea, Eukarya)
Taxonomic rankings
• Organisms are ranked in
taxa that range from broad
characteristics to very specific
ones.
• Broader taxa have more general
characteristics and more species in it.
• K-P-C-O-F-G-S
• Kings Play Chess On Fine Green Silk
Binomial nomenclature
• Developed by Linnaeus
• Identify organism’s by their genus and species
(specific epithet).
– Genus: a group of similar species
– Specific epithet: second word, sometimes
descriptive.
• This is a species’ scientific name.
– i.e. Myrmecophaga tridactyla
Why scientific names?
• Found in the US, England, Spain, Holland and Sweden
• Name is italics or each word underlined. First word
capitalized. Second lower case such as Canis lupus
KEY CONCEPT
Modern classification is based on evolutionary
relationships.
Cladistics is classification based on
common ancestry.
• Phylogeny is the evolutionary history for a group of
species.
– evidence from living species, fossil record, and molecular data
– shown with branching tree diagrams
• Cladistics is a common method to make evolutionary
trees.
– classification based on common ancestry
– species placed in order that they descended from
common ancestor
• A cladogram is an evolutionary tree made
using cladistics.
– A clade is a group of species that shares a common
ancestor.
– Each species
in a clade
shares some
traits with the
ancestor.
– Each species
in a clade has
traits that
have
changed.
Procynosuchus
– A clade is a
group of
species that
shares a
common
ancestor.
Each species in a
clade has traits
that have
changed.
Bell
Work
• Derived character is a trait present in a clade but
absent in the last common ancestor of the group.
• Nodes represent the most recent common ancestor of
a clade.
• Clades can be identified by snipping a branch under a
node.
Molecular evidence reveals species’
relatedness.
• Molecular data may confirm classification based on
physical similarities.
• Molecular data may lead scientists to propose a new
classification.
•
DNA is usually given the last word by scientists.
Creating a cladogram
Bell Work: EOI question
Chapter 17 Section 2
Six Kingdoms
The Six Kingdoms
Sometimes you hear there are only five kingdoms and Bacteria and
Archaebacteria are grouped together into one Kingdom
(Prokaryotes or Monera)
The Six Kingdoms
The main factors that determine which kingdom and organism is
classified in are:
1. Cellular structure
2. Means of obtaining energy
Kingdoms 1 &2: Prokaryotes
Prokaryotes are unicellular organisms that do not have a
true nucleus bound by a membrane
1. Archaebacteria
LINK
• Structure: unicellular; lack membrane
bound nucleus
• Energy:
– Heterotrophy
– Autotrophy
• Some chemosynthetic
• Others photosynthetic
• Live in extreme environments
• Domain Arachaea
Vocab:
Heterotroph
Autotroph
Chemosynthetic
2. Eubacteria
• Structure: unicellular, lack membrane-bound
nucleus
• Energy:
– Heterotrophy
– Autotrophy
• Some chemosynthetic
• Others photosynthetic
• Found everywhere but in
extreme environments
• Domain Bacteria
3. Fungi
• Structure:
– Some unicellular (yeast)
– Some multicellular
• Energy:
– Heterotrophy
• Absorb nutrients from organic materials in the
environment
• Domain: Eukarya
Defining Characteristic:
Absorbing nutrients from
dead/decaying materials
in the environment
Nucleus hangs back
and “directs”
Product diffuses back
into hypha and is used
4. Plants
• Structure:
– Multicellular
– Cells contain a cell wall
– Complex organisms, contain organ systems
• Energy:
– Autotrophy
• Photosynthetic
• Domain Eukarya
5. Animals
• Structure:
– Multicellular
– Complex organisms, contain organ systems
• Energy:
– Heterotrophy
• Herbivores, carnivores, omnivores
• Domain Eukarya
Vocab:
Herbivore
Carnivore
omnivore
6. Protists
• Structure:
– Some unicellular; some multicellular
– Lack complex organ system
• Energy:
– Autotrophy (obtain energy like plants)
– Heterotrophy (obtain energy like animals)
LINK
What am I?
• The Dendroaspis polylepis is the largest of its kind,
can grow to 14 feet, and is considered to be very
poisonous. It is a skillful hunter, using its venom and
strong muscles to kill its prey
• Characteristics:
• Kingdom:
Black mamba
What am I?
• The phyllostachys nigra can grow to 35 feet and is
found in tropical regions of the world. Despite its
inability to move from place to place, it has welldesigned organ systems to create its own nutrients
and to transport those nutrients.
• Characteristics:
• Kingdom:
Black bamboo
What am I?
• The Paramecium caudatum is a unicellular organism
that has a membrane-bound nucleus. It has special
hair-like projections called cilia that it uses for
locomotion and to capture food.
• Characteristics:
• Kingdom:
What am I?
• The Streptococcus pyogenes is a single cell organisms
that lacks a true nucleus. It is commonly found
throughout the world and is a major cause of human
sickness.
• Characteristics:
• Kingdom:
What am I?
• The Undaria pinnatifida is an edible plantlike
organism found in the sea. It is photosynthetic, but
lacks the organ systems to transport the nutrients it
synthesizes
• Characteristics:
• Kingdom:
What am I?
• The Haloarcula hispanica is found in the hypersaline
waters of southeastern Australia.
• Characteristics:
• Kingdom:
Extremophiles at Yellowstone hotsprings
What am I?
• The Amanita muscaria is a poisonous multicellular
organism. Despite its inability to move from place to
place, it is able to steal nutrients from dead and
decaying organisms in its environment
• Characteristics:
• Kingdom:
California fungi