Download Classification

Classification
The Science of Organizing
What are you expected to
know?
 1. Describe how and why organisms
are hierarchically classified and
based on evolutionary relationships.
 2. Discuss distinguishing
characteristics of the domains and
kingdoms of living organisms.
 3. Explain the reasons for changes
in how organisms are classified.
Some vocabulary we
need…
 Biodiversity: variety of
organisms on Earth
(almost 2 million
named)
 Taxonomy: the science
of grouping organisms
according to their
presumed evolutionary
relationships and
similar characteristics
More Vocabulary…
 Taxon (plural=taxa): any particular group
within a taxonomic system
 Phylogeny: an organism’s evolutionary
history and how it has changed over time
(helps scientists know ancestors)
Button Activity
History of Classification
 A. Aristotle (4th century BC)
 1. Classified animals according to the way
they moved or where they lived – air, land,
or water
Useful but problematic Ex. Bird vs. Bat
 FROGS – land or water??
Problems
Aristotle
 2. Classified plants on stem differences
-herbs, shrubs, trees
 3. Common names
 were misleading
 (jellyfish, dragonfly)
History of Classification
 B. John Ray (1600s English biologist)
 1. Classified all plants and animals in
England based on internal anatomy and
behavior
 2. First to use term species (same species to
produce young)
Carolus Linnaeus (1700s
Swedish naturalist)
classified according to form and structure –
morphology
 hierarchical categories – larger, general
groups  smaller, specific
(Larger groups are more
inclusive and smaller
groups are more exclusive)
 7 levels of organization
7 levels of organization







Kingdom
Phylum
Class
Order
Family
Genus
Species
To remember this
 King Phillip called to order a fried grouper
sandwich.
Carolus Linnaeus
 Latin - universally accepted
 Cat vs. gato (Spanish) vs. chat (French) vs.
katze (German)
Binomial Nomenclature
 2-part name known as binomial
nomenclature (genus and species)
 Scientific name- Homo sapiens (genus and
species)
 Our cat would be called Felis catus (in any
country)
Binomial nomenclature
 Felis catus - house cat
 Felis concolor - cougar
 Felis rufa – bobcat
3 different species BUT
same genus
Classification of humans
Classification Changes
 Domains added (categories above
kingdom level)
 Ex: Eukarya and Prokarya
 Plant Kingdom: divisions instead of
phyla; species divided into varieties
 Animal Kingdom: species further divided
into subspecies to designate varieties of
species that occur in different geographic
locations
Different Forms of Classification
 Serial Ordering: category by extent of
sharing a property
 Ex: Moh’s Hardness Scale (#1-#10),
earthquakes, hurricanes, tornadoes
Different Forms of Classification
 Binary Stage: Object has characteristic or
does not (Yes or No)
 Ex: Vertebrates or Not Vertebrates
(Invertebrates)
Different Forms of Classification
 Multistage: Set of objects sorted into
subsets and each subset is sorted again
and again into several layers
Classification Activity
with Mythical Organisms
Modern classification
 A. There are 2 main groups used to
classify organisms.
 prokaryotes and eukaryotes
 B. Scientists studied the macromolecules
(especially the rRNA) of organisms in
these 2 groups and decided that they
needed to revise the classification
system.
 C. They got 3 new insights from their
studies that they used to revise the
system.
1. All living organisms inherited their
rRNA genes from a last universal
common ancestor.
2. All living things can be divided into 3
lineages or domains.
-Bacteria, Archaea, Eukarya
3. Archaea differ greatly from bacteria
3 Domains of Life on Earth
Domain Bacteria
 1. small, single celled
 2. Prokaryotic (lack a
true nucleus)
 3. Have a cell wall
and plasma
membrane
 4. One circular
chromosome
 5. Oldest known
fossils of cells
Domain Archaea
 1. Prokaryotes
 2. Distinctive cell
membranes
 3. Autotrophic
(chemosynthesis),
earliest organisms on
Earth
 4. Some produce gases
 5. Live in harsh
environments
Domain Eukarya




1. Eukaryotic
2. Large cells
3. True nucleus
4. Complex cellular
organelles
 5. Plants, animals,
fungi, plus variety of
single-celled
organisms
Kingdom Eubacteria
“true bacteria”
 Prokaryotic
 Have cell wall and
cell membrane
 All unicellular
 Heterotrophic and
autotrophic
 Motile (flagella)
 Examples: E.coli,
Cyanobacteria,
Chlamydia (STI)
Kingdom Archaebacteria
“ancient bacteria”
 Prokaryotic
 Have cell wall and cell
membrane
 Unicellular
 Heterotrophic and
autotrophic
 Motile
 Ex: methanogens
(gas), halophiles (salt),
thermoacidophiles (hot
springs)
Kingdom Protista
 Eukaryotic
 Have cell wall (some)
and cell membrane
 Mostly unicellular,
some multicellular
forms
 Autotrophic,
heterotrophic
 Motile
 Ex: Euglena,
Paramecium,
Amoeba
Kingdom Fungi
 Eukaryotic
 Have cell wall and
cell membrane
 Unicellular and
multicellular
 Heterotrophic
(secrete digestive
enzymes)
 Sessile
 Ex: Mushrooms,
puffballs, mildew,
mold
Kingdom Plantae
 Eukaryotic
 Have cell wall and
cell membrane
 Multicellular
 Autotrophic
(photosynthesis)
 Sessile
 Ex: Ferns, mosses,
pine tree
Kingdom Animalia






Eukaryotic
Have cell membrane
Multicellular
Heterotrophic
Motile
Ex: Worms, fish,
humans (Largest
kingdom!)