Transcript Learning Goal 5

LG 5
Classification
Scientific Names
Two-Word System –
Binomial Nomenclature –
Linnaeus’s System of Classification
Carolus Linnaeus –
Hierarchy of Classification –
Kingdoms and Domains
2 Kingdoms –
5 Kingdoms –
6 Kingdoms –
The Three-Domain System
Eukarya –
Bacteria –
Archaea –
Characteristics Used to Group Organisms into Kingdoms
Cell Type –
Cell Structures –
Number of Cells –
Mode of Nutrition –
Identifying Organisms
Dichotomous Keys –
Unit V
Evolution
LG 5
Explain how species are classified
using the science of taxonomy.
Scientific Names
• Each species is
assigned a two-word
scientific name that is
the same throughout
the world, even though
common names may be
different.
• This eliminates
confusion.
• Example: In England
the word buzzard refers
to a hawk, where in the
U.S. it refers to a
vulture.
• This is called binomial
nomenclature. The
scientific name of an
organism consists of its
Genus and species.
• Example: The grizzly
bear is Ursus arctos.
Many bears belong to
the genus Ursus and
the grizzly is the only
member of the species
arctos.
Linnaeus’s System of
Classification
• Carolus Linnaeus
(1707-1778) was a
Swedish botanist
and developed the
two-word naming
system.
• He also came up with
the seven level
hierarchy of
classification still used
today. The levels from
smallest to largest are
species, genus, family,
order, class, phylum
and kingdom.
• Each level is called a
taxon, and the study of
classification is called
taxonomy.
Kingdoms and Domains
• 2 Kingdoms
• Linneaeus originally
separated all
organisms into only
2 kingdoms; Plants
and Animals
5 Kingdoms
• Later, as biologists
learned more about the
natural world they
realized that
microscopic organisms,
as well as fungi and
algae needed their own
kingdoms because of
their many differences
from plants and animals
so the 5 kingdoms
system was developed;
Animalia, Plantae,
Fungi, Protista, and
Monera (bacteria)
6 Kingdoms
• As more evidence
about microorganisms
continued to
accumulate, biologists
came to recognize that
the Monera were
composed of two
distinct groups so
many consider them
members of two
kingdoms, Eubacteria,
and Archaebacteria
The Three-Domain System
• Domains are groupings
larger than kingdoms.
They are:
• Eukarya-contains
protists, fungi, plants,
and animals
• Bacteria-contains
eubacteria
• Archaea-contains the
archaebacteria
Characteristics Used to Group
Organisms into Kingdoms
• Cell Type prokaryotic (no
nucleus) or
eukaryotic (have
nuclei)
• Cell Structures - cell
wall types,
chloroplasts
• Number of Cells –
unicellular or
multicellular
• Mode of Nutrition –
autotrophic or
heterotrophic
Identifying Organisms
• A dichotomous key is a tool
that allows the user to
determine the identity of items
in the natural world, such as
trees, wildflowers, mammals,
reptiles, rocks, and fish.
• Keys consist of a series of
choices that lead the user to
the correct name of a given
item. "Dichotomous" means
"divided into two parts".
Therefore, dichotomous keys
always give two choices in
each step.