SC.912.L. 15.6 Discuss distinguishing characteristics of the
domain and kingdoms of living organisms.
CC: RST. 11-12.1, SL.11-12.4, MP.4
Polar bears and Brown Bears are
their common names but how can we
scientifically name them?
How do you know the cat on the left?
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Puma
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Mountain lion
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Florida panther
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Cougar
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Puma concolor= cougar
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Puma concolor coryi= florida
panther
COMMON NAME
SCIENTIFIC NAME
Vary among languages and from place
to place
• Cougar, mountain lion, puma, panther
Binomial Nomenclature- two word naming system
• Created by botanist Carolus Linnaeus
• Written in italics
• First word begins with a capital letter
• Second word is lowercased
Different species can have the same
common name
• Buzzard (UK)- hawk
• Buzzard (USA)- vulture
 First part of the name is the Genus to which the
organism belongs.
• Genus- group of similar species
 Second part of the name is unique to each species.
• Description of an important trait or the
organism’s habitat
Example: Polar Bear
Example: Ursus maritimus
 Used to identify organisms
 Series of paired statements or questions that describe alternative possible
characteristics of an organism.
 System that organized species into taxa that formed a hierarchy or set of ordered ranks.
Taxa
Description
Species
Group of individuals
capable of interbreeding
and producing fertile
offspring.
Genus (plural: genera)
Group of similar species
Family
Several Genera that share
similar characteristics.
Order
Closely related families
are grouped into the next
larger rank.
Class
Similar orders
Phylum
Classes are grouped into
a phylum
Kingdom
Largest and most
inclusive
Problems with
Traditional Classification
• Linnaeaus System is based on similarities and
differences
• The crab, barnacles, and limpet share some
similarities and differences.
• Under traditional classification, crabs would be
classified into a separate group.
BUT LOOKS can be deceiving!
Look more closely!
LIMPET
BARNACLE
Limpet and barnacle larvae are very different.
Barnacles have jointed limbs.
Limpets DON’T !
Barnacles have a segmented body
Limpets DON’T !
Barnacles have an exoskeleton that molts.
Limpets DON’T !
CRAB
Look more closely!
LIMPET
CRAB
BARNACLE
Crab and barnacle larvae are very similar
Barnacles have jointed limbs.
So do CRABS !
Barnacles have a segmented body
So do CRABS !
Barnacles have an exoskeleton that molts.
So do CRABS !
LIMPET
SNAIL
Limpets have an internal anatomy more like
snails, which are MOLLUSKS.
Because of these characteristics, scientists have
concluded that barnacles are more closely
related to crabs than to MOLLUSKS
BOTH crabs and barnacles have been classified as CRUSTACEANS
Scientists today try to assign species to a larger group in ways
that reflect how closely members of those groups are related to
each other.
Evolutionary Classification- grouping organisms based on evolutionary history.
• Phylogeny: evolutionary history of lineages.
 Common ancestors get placed in higher taxa
whose members are more closely related to
one another than to any other group.
 This classification system groups organisms
into groups called CLADES.
Clades- group of species that
includes
1. single common ancestor
2. and all descendants of
that ancestor—living and
extinct.
•
Links groups of organisms by
showing how evolutionary lines, or
lineages, branches off from
common ancestors.
Derived Characters- a trait that arose in the most recent
common ancestor of a particular lineage and was passed along
to its descendants.
• certain kinds of characters are looked at when assigning
organisms into clades unlike Linnaeaus classification.
 Linnaean Class Reptilia is not a clade
because it does NOT include modern
birds.
Birds are descendants
of reptiles, which can be seen
from the cladogram on the right!
 Genes can be derived characters.
 The more derived GENETIC characters
two species share, the more recently
they shared a common ancestor and the
more closely they are related in
evolutionary terms.
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Prokaryote- unicellular organism that lacks a nucleus
Eukaryote- organisms whose cells contain a nucleus
Peptidoglycan- serves a structural role in the walls of bacteria.
Cellulose- provides strength and rigidity to plant cells
Chitin- tough, protective covering or structural support for certain organisms.
Chloroplast- organelle found in cells of plants and some other organisms that
captures the energy from sunlight and converts it into chemical energy.
Multicellular- two or more cells in an organism
Unicellular- organism is made up of one cell.
Autotroph- organism that is able to capture energy from sunlight or chemicals and
use it to produce its own food from inorganic compounds—producer.
Heterotroph- organism that obtains food by consuming other living things—
consumer.