|
Classification of Organisms is
done by Taxonomists -
SYSTEMIC BIOLOGISTS
Campbell - Concept Activities - chapter
1.2 -
Classifying Schemes*.
In biological
taxonomy, kingdom
is (historically) the highest rank. Currently, many textbooks use
a six kingdom system:
Monera
(=Archaea, Bacteria),
Protista,
Fungi,
Animalia, &
Plantae).
Each
kingdom is divided into smaller groups called
phyla (or
"divisions").
Kingdoms pic*
Recent molecular evidence places all Living Organisms into
a higher rank, a Domain...
EUBACTERIA - true bacteria
3
DOMAINS*
NAS-8 ARCHAEA - ancient prokaryotes (bacteria)
EUCARYOTA - modern eukaryotes
Carl
Woese, (perspectives)
established new divisions of life based upon
molecular similarity of rRNA.
all cells are known to contain the
same organelle - the ribosome, site of protein
synthesis.
he compared
the nucleotide sequences of
small-unit
rRNA from many species...
rRNA... is FOUND
in ALL cells with ribosome and therefore,
if all cells are derived from a
common progenitor[NAS-1], their
rRNA sequence changes
 over evolutionary time can indicate
divergence
(loss of relatedness) through phylogeny.
Woese described...
the EUBACTERIA, as single celled life
without nuclei
are akin to common prokaryotes, but look similar to Archaea
the ARCHAEA, as a prokaryotic-like
group that
thrive in extreme environments:
acid springs
"extremophiles"
arctic ice,
hydrothermal vents at deep oceans volcanoes,
with crevices of solid rock in mines, etc....
this group contains distinctive and varied chemical processes and a unique
genetic makeup
the EUCARYOTA, which encompass all
life based upon cells with nuclei, including
plants, animals, fungi, and single celled protists.
by
comparing similar & divergent sequences, the RNA phylogeny tree
produced, a tree with
3
distinct branches (Domains)
comparing the 3 Domains*later
and within the more traditional divisions of life we describe the... [Collage]
6 KINGDOMS - a
primary classification of organisms reflecting
fundamental patterns of relationships
in the natural world
MONERA - single celled, microscopic
bacteria & archaea; most successful of organisms
PROTISTA - algae/protozoans; unicellular eucaryotes
PLANTAE - contains plants,
photosynthetic organism with cellulosic cell walls
FUNGI - contains molds, yeasts,
& mushrooms,
organisms that decompose dead organisms
ANIMALIA - kingdom that contains animals;
organisms that eat other organisms &
lack cellulosic cell walls; often motile
Campbell - Concept Activities - chapter
1.2 -
Classifying Schemes*.
copyright
c2008 Last update -
Thursday, September 03, 2009
back Charles Mallery,
Biology 150, Department of Biology, University of Miami,
Coral Gables, FL 33124
|
