CLASSIFICATION:
FINDING ORDER IN DIVERSITY
CHAPTER 18 – LESSON 1
LEARNING GOAL
• Describe the goals of binomial nomenclature and identify
the taxa in the classification system devised by Linnaeus.
• Name the 6 kingdoms of life as they are currently
identified and explain what the tree of life represents.
WHY DO WE ORGANIZE THINGS?
ORGANIZE THE CANDY!
• Grab a partner. Sort the following 15 candy types into groups, in any
way you choose!
Blow Pops
Tootsie Pops
Dum Dums
ORGANIZE THE CANDY!
Non-Chocolate
vs.
Chocolate
ORGANIZE THE CANDY!
Non-Chocolate
vs.
Chocolate
ORGANIZING (CATEGORIZING) THE DIVERSITY OF
LIFE
• About 8.7 million different
species of life on Earth
(give or take 1.3 million)
• We need a way to
organize them all!
Source: Census of Marine Life. "How many species on Earth? About 8.7 million, new estimate says." ScienceDaily.
ScienceDaily, 24 August 2011. <www.sciencedaily.com/releases/2011/08/110823180459.htm>.
WHY DO SCIENTISTS CLASSIFY THINGS?
• Scientists classify (or organize) living things by characteristics
they share.
• Classification helps us answer questions such as:
• How many kinds of living things are there?
• What characteristics define each kind of living thing?
• What are the relationships among living things?
HOW DO SCIENTISTS KNOW LIVING THINGS ARE
RELATED?
• Scientists use both physical and chemical characteristics to
determine whether or not organisms are related.
• Physical Characteristics
• Skeletal Structure
• Development from Egg to Adult
• Chemical Characteristics
• DNA
• Proteins and Hormones
START WITH THE BASICS:
COMMON VS. SCIENTIFIC NAMES
• Common names for species around
the world can be different
• For example, what is this animal
called?





Puma
Cougar
Panther
Mountain Lion
Catamount and more!
START WITH THE BASICS:
COMMON VS. SCIENTIFIC NAMES
• They all stand for the same animal!
• This can get confusing, so scientists
use a scientific name to properly
identify this species.
 Puma concolor
 Holds the Guinness Record for
an animal with the most
amount of names.
CARL LINNAEUS & BINOMIAL NOMENCLATURE
• 1730s – Swedish botanist Carolus (Carl)
Linnaeus developed a two-word scientific
naming system called binomial nomenclature.
• Binomial = “two-part name”
• Nomenclature = “naming something”
RULES FOR WRITING SCIENTIFIC NAMES
• The two parts are the genus name and species name
The genus name is written first, followed by the species name.
The first letter of the genus name is capitalized.
The first letter of the species name is lowercase.
The entire name is written in italics or underlined.
Ex: Puma concolor or Puma concolor
LEVELS OF CLASSIFICATION: TAXONOMY
• Taxonomy is the science of describing, classifying, and
naming living things.
• Scientists use an 8 level system to classify living things.
• This system starts with the broadest (or most general) level
and ends with the smallest (or most specific) level.
LEVELS OF TAXONOMY
• The levels are: Domain, Kingdom, Phylum, Class,
Order, Family, Genus, and Species.
Use a mnemonic device to remember!
• Did King Phillip Come Over For Grandma’s Spaghetti?
• Drunken Kangaroos Punch Children On Family Game Shows
• Dumb Kids Playing Catch On Freeway Get Smashed
THE THREE DOMAINS:
• Bacteria
• Prokaryotes that are single celled and lack a nucleus.
• Usually have a cell wall.
• Reproduce by cell division.
• Archaea
• Prokaryotes that live in very harsh conditions.
• Eukarya
• Eukaryotes that can be single or multi cellular (with nuclei).
• More complex than other two domains.
• Include protists, fungi, plants, and animals.
THE 6 KINGDOMS:
KINGDOMS IN THE DOMAIN
EUKARYA
• Kingdom Animalia
• Kingdom Protista
• Kingdom Plantae
• Kingdom Fungi