WHY DO SCIENTISTS CLASSIFY?
• Classification: the process of grouping things based on
their similarities
• Biologists use classification to organize living things into
groups so that the organisms are easier to study
• The scientific study of how living things are classified is
called TAXONOMY
• Once a scientist classifies an organism, they know a lot
more about the organisms
• For example…a bird… what do we know??
THE NAMING SYSTEM LINNAEUS
• Carl Linnaeus--- botanist, physician, zoologist
(1750s)
• Linnaeus placed organisms in groups based on
observable features
• The same classification system is still used
today!!
• Each organisms got a two-part scientific name =
BINOMIAL NOMENCLATURE
• What does “binomial” mean?!
GENUS AND SPECIES
• Binomial nomenclature, the two parts of the name are the
1. Genus (genera)
2. Species
• What’s the difference?
• GENUS: is a classification grouping that contains SIMILAR,
closely related organisms.
• Example: pumas, jaguar, tiger, house cats (genus: Felis)
• SPECIES: is a group of similar organisms that can mate with
each other and produce offspring that can also mate and
reproduce
• Example: the name includes where it lives or its
appearance
BINOMIAL NOMENCLATURE RULES
• A complete scientific name is written in italics
• Only the first letter of the first word is
CAPITALIZED
• Genus species (Correct way to write it!)
RIGHT!!!
Felis Concolor
(Puma)
WRONG!!!
Carcharodon carcharias
(Great White Shark)
caretta caretta
(Loggerhead Turtle)
WRONG!!!
WHY BINOMIAL NOMENCLATURE?
• Easy for scientists to communicate
• Written in one language, LATIN (language scientists used
at that time)
• Scientists around the world use the same name for the
same organism
• Example---
We call this animal
a woodchuck,
groundhog, or
whistlepig… why
not give it one
universal name?
Marmota monax
LEVELS OF CLASSIFICATION
• There are 8 levels of classification
• BROAD >>>>>> MORE SPECIFIC
• The more classification levels that two organisms
share, the more characteristics they have in common.
(page 46)
HOW AM I GOING TO REMEMBER THE LEVELS
IN ORDER?
Did King Phillip Come Over For
Good Spaghetti?
DOMAINS AND KINGDOMS
• Three domains: BACTERIA, ARCHAE, EUKARYA
• Organisms are placed into domains and kingdoms
based on
• CELL TYPE
• THEIR ABILITY TO MAKE FOOD
• NUMBER OF CELLS IN THEIR BODIES
BACTERIA
• Are all around you!
• Can be both autotrophic or heterotrophic
• Prokaryotes
• Organisms whose cells lack a nucleus, therefore
the nucleic acids float in the cell
• What is a NUCLEUS?
• Dense area in a cell that contains nucleic acids
• Compare it to a captain of a team
ARCHAE
• Found in EXTREME environments
• Examples: hot springs, very salty water, swamps,
and intestines of cows
• Can be both autotrophic or heterotrophic
• Unicellular prokaryotes (similar to bacteria)
• Archae means “ancient”
• Similar conditions of ancient Earth
Dead Sea
DOMAIN EUKARYA
• Eukaryotes: Organisms with cells that
contain nuclei
1. Protists
2. Fungi
3. Plants
4. Animals
PROTISTS
• Can be both autotroph OR
heterotroph
• Can be both unicellular OR
multicellular (seaweeds)
• “odds and ends”
FUNGI
• Mushrooms, mildew, and molds
• Can be both multicellular OR
unicellular (yeast for breads)
• ONLY HETEROTROPHS
PLANTS
• All MULTICELLULAR EUKARYOTES, AUTOTROPHS
• Plants provide food for most of the heterotrophs
on land
Animals
• All multicellular eukaryotes, heterotrophs