Chapter 12: Classification
Essential Question: How are living
things organized and named?
I. Biodiversity: variety of organisms
A. Classifying organisms
1. Taxonomy: branch of biology that names and
groups organisms according to their
characteristics and evolutionary history
a) taxon (taxa): particular group within a
taxonomic system
2. Common names were confusing and varied
from place to place
3. Long descriptions in Latin were used but they
were difficult to remember
B. Linnaeus’s system (1700’s)
1. Use organisms’ form and structure to group them into
categories
a) kingdom was the largest group
b) plant and animal kingdoms
2. Levels of classification
a) kingdom: largest category
b) phylum
c) class
d) order
f) genus
e) family
g) species: single organism type
Classification
Classification of Ursus arctos
Section 18-1
Grizzly bear Black bear
Giant
panda
Red fox
Coral Sea star
Abert
squirrel snake
KINGDOM Animalia
PHYLUM Chordata
CLASS Mammalia
ORDER Carnivora
FAMILY Ursidae
GENUS Ursus
SPECIES Ursus arctos
Go to
Section:
3. Binomial nomenclature: species name has two-parts
and is written in italics Binomial nomenclature
a) first name: genus (capital letter)
b) second name: species identifier and usually a
descriptive word (small cased letter)
c) example: Homo sapiens (wise human)
d) written in Latin so all scientists can identify the
organism
4. Modern system has domain level above kingdom
The Linnaean System of Classification
Scientific Names
Why not just use common names?
Potato Bug
Roly Poly Bug
Sow Bug
Pill Bug
Dandelion
Irish Daisy
Lion’s tooth
Priests crown
Mountain Lion
Cougar
Puma
OR
OR
OR
Armadillium vulgare
Taraxacum officinale
Puma concolor
Review
Binomial Nomenclature Rules:
 All scientific names are in Latin (same for all
scientists, same in every language).
 Consists of a genus (first part) and species
descriptor (second part).
 Genus is capitalized and species is in lower case.
 Genus and species names are either underlined or
italicized.
II. Systematics: organizes living things by similarities in
embryos, chromosomes, proteins, DNA, fossils
A. Phylogenetics: analysis of evolutionary
relationships among taxa
1. Phylogenetic diagram/tree: family tree
that shows the evolutionary relationships
thought to exist among groups of
organisms
2. Fossil record: one form of evidence
used in making a phylogenetic tree that
can provide clues to evolutionary relationships
3. Morphology: study of the
internal and external structures
of organisms: the greater
the number of homologous
Morphological features, the
more closely related they are
4. Embryological patterns of development:
provide evidence of phylogenetic
relationships based on similarity among
embryos of different species
5. Chromosomes and DNA: compare DNA,
RNA, and chromosomes of different species:
same patterns show how closely they are
related
B. Cladistics: use shared derived characters to establish
evolutionary relationships
1. Derived character: feature that apparently
evolved only within the group under consideration
2. Example: birds have a derived character of
feathers, most animals do not have feathers other
than birds
3. Shared character: feature that all members of a
group have in common
4. Cladograms: ancestry diagrams made by means
of cladistic analysis
Cladistics
Section 18-2
Traditional
Appendages
Crab
Classification Versus Cladogram
Conical Shells
Barnacle
Limpet
Crustaceans
Crab
Gastropod
Barnacle
Limpet
Molted
exoskeleton
Segmentation
Tiny free-swimming larva
TRADITIONAL
CLASSIFICATION
Go to
Section:
CLADOGRAM
Another Cladogram
Node
Derived
Characteristics
III. Modern classification
A. Three Domains of life: all living things seems to be
related by ancestry to one of three major lineages or
domains
1. Domain Bacteria:
Eubacteria kingdom
2. Domain Archaea: includes the Archaebacteria
kingdom
3.Domain Eukarya: includes the Protista, Fungi,
Plantae, and Animalia kingdoms
B. Six Kingdom system: first kingdom aligns
with domain Bacteria, second kingdom with
domain Archaea, and the last four kingdoms
with the domain Eukarya
• Kingdoms
• Domains and kingdoms
1. Kingdom Eubacteria
a) unicellular prokaryotes
b) “eu” means true
c) bacteria that affects your life
Spirochetes
Lyme’s disease
Tooth Decay
Bacteria
Food
Poisoning
Bacteria
Cyanobacteria
(blue-green bacteria)
2. Kingdom Archaebacteria
a) unicellular prokaryotes
b) distinctive cell membranes and genetic
properties
c) live in harsh environments
d) “archae” means ancient
Archaebacteria at Yellowstone
National Park
Morning Glory Hot Spring
Archaebacteria at Yellowstone
National Park
3. Kingdom Protista
a) most are single celled eukaryotes
b) some are multicellular
c) very different from each other
d) placed in category if not a fungi, plant, or
animal
Photosynthetic
(chloroplasts) or
heterotrophic.
Paramecium
Euglena
Ameoba
Heterotrophic,
respond to touch
and light.
Ephelota
Didinium
Stentor
Euplotes
Ceratium
4. Kingdom Fungi
a) heterotrophic unicellular and multicellular
eukaryotes
b) absorb nutrients
c) include mushrooms,
mildew, and molds
Poisonous Mushrooms
Amanita
Most poisonous mushrooms secrete
muscarin – causes excessive saliva,
tears, sweating, diarrhea,vomiting.
Puffballs
Yeast
Rusts
Smuts
Ringworm
Athletes Foot
Mildew and Mold
Slime mold
Penicillin
5. Kingdom Plantae
a) multicellular plants
b) photosynthesis
c) includes: mosses,
ferns, conifers, and
flowering plants
Venus Fly Trap
Pitcher Plant
Mosses
Clubmosses
Horsetails
Ferns
Gymnosperms
Angiosperms
6. Kingdom Animalia
a) multicellular
heterotrophs
b) most move about in
their environment
Phylum Porifera
Phylum Cnidaria
Giant jellyfish
Box jelly
Phylum Platyhelminthes
Phylum Nematoda
Phylum Annelida
“WORMS”
Phylum Mollusca
Phylum Echinodermata
Phylum Vertebrata
Concept Map
Section 18-3
Living
Things
are characterized by
Eukaryotic
cells
and differing
Important
characteristics
which place them in
Cell wall
structures
such as
Domain
Eukarya
Prokaryotic cells
which is subdivided into
which place them in
Domain
Bacteria
Domain
Archaea
which coincides with
which coincides with
Kingdom
Eubacteria
Kingdom
Archaebacteria
Go to
Section:
Kingdom
Plantae
Kingdom
Fungi
Kingdom
Protista
Kingdom
Animalia
Section 18-3
Cladogram of Six Kingdoms and
Three Domains
DOMAIN
ARCHAEA
DOMAIN
EUKARYA
Kingdoms
DOMAIN
BACTERIA
Go to
Section:
Eubacteria
Archaebacteria
Protista
Plantae
Fungi
Animalia
Section 18-3
Key Characteristics of Kingdoms and
Domains
Classification of Living Things
DOMAIN
Bacteria
Archaea
KINGDOM
Eubacteria
Archaebacteria
CELL TYPE
Protista
Fungi
Plantae
Animalia
Prokaryote
Prokaryote
Eukaryote
Eukaryote
Eukaryote
Eukaryote
Cell walls with
peptidoglycan
Cell walls
without
peptidoglycan
Cell walls of
cellulose in
some; some
have
chloroplasts
Cell walls of
chitin
Cell walls of
cellulose;
chloroplasts
No cell walls
or chloroplasts
Unicellular
Unicellular
Most unicellular;
some colonial;
some
multicellular
Most
multicellular;
some
unicellular
Multicellular
Multicellular
MODE OF
NUTRITION
Autotroph or
heterotroph
Autotroph or
heterotroph
Autotroph or
heterotroph
Heterotroph
Autotroph
Heterotroph
EXAMPLES
Streptococcus,
Escherichia coli
Methanogens,
halophiles
Amoeba,
Paramecium,
slime molds,
giant kelp
Mushrooms,
yeasts
Mosses, ferns,
flowering
plants
Sponges,
worms,
insects, fishes,
mammals
CELL
STRUCTURES
NUMBER OF
CELLS
Textbook p. 349
Go to
Section:
Eukarya
IV. Dichotomous Keys
A. Dichotomous key: series of paired
statements that describe physical
characteristics of different organisms
B. Used to identify unfamiliar organism
Sample Dichotomous key for beans:
1.a. If the bean is round ….. it is a garbanzo bean.
1.b. If the bean is oblong ….. go to step 2.
2.a. If the bean is white ….. it is a white northern bean.
2.b. If the bean is dark-colored ….. go to step 3.
3.a. If the bean is a solid color ….. go to step 4.
3.b. If the bean is speckled ….. it is a pinto bean.
4.a. If the bean is black ….. it is a black bean.
4.b. If the bean is reddish-brown ….. it is a kidney bean.