| Table 1. The Five
Kingdoms.
Monera, the most primitive kingdom, contain
living organisms remarkably similar to ancient fossils. Organisms in this
group lack membrane-bound organelles associated with higher forms of life.
Such organisms are known as prokaryotes. Bacteria (technically the
Eubacteria) and blue-green bacteria (sometimes called blue-green algae, or
cyanobacteria) are the major forms of life in this kingdom. The most
primitive group, the archaebacteria, are today restricted to marginal
habitats such as hot springs or areas of low oxygen concentration.
 
Representative photosynthetic
cyanobacteria: Oscillatoria (left) and Nostoc (right). The
above left image is cropped from gopher://wiscinfo.wisc.edu:2070/I9/.image/.bot/.130/Cyanobacteria/Oscillatoria_130.
The above image right is cropped from gopher://wiscinfo.wisc.edu:2070/I9/.image/.bot/.130/Cyanobacteria/Nostoc_130.
Protista were the first of the eukaryotic
kingdoms, these organisms and all others have membrane-bound organelles,
which allow for compartmentalization and dedication of specific areas for
specific functions. The chief importance of Protista is their role as a
stem group for the remaining Kingdoms: Plants, Animals, and Fungi. Major
groups within the Protista include the algae, euglenoids, ciliates,
protozoa, and flagellates.
 
Scanning electron micrographs of diatoms (Protista).There
are two basic types of diatoms: bilaterally symmetrical (left) and
radially symmetrical (right). Images are from http://WWW.bgsu.edu/departments/biology/algae/index.html.
  
Light micrographs of some protistans. The
above images are Copyright 1994 by Charles J. O'Kelly and Tim Littlejohn,
used by permission from: http://megasun.bch.umontreal.ca/protists/gallery.html.
Fungi are almost entirely multicellular
(with yeast, Saccharomyces cerviseae, being a prominent unicellular
fungus), heterotrophic (deriving their energy from another organism,
whether alive or dead), and usually having some cells with two nuclei
(multinucleate, as opposed to the more common one, or uninucleate) per
cell. Ecologically this kingdom is important (along with certain bacteria)
as decomposers and recyclers of nutrients. Economically, the Fungi provide
us with food (mushrooms; Bleu cheese/Roquefort cheese; baking and
brewing), antibiotics (the first of the wonder drugs, Penicillin, was
isolated from a fungus Penicillium), and crop parasites (doing
several billion dollars per year of damage).
  
Examples of fungi. The above images are
from http://www.cinenet.net/users/velosa/thumbnails.html.
Plantae include multicelled organisms that
are all autotrophic (capable of making their own food by the process of
photosynthesis, the conversion of sunlight energy into chemical energy).
Ecologically, this kingdom is generally (along with photosynthetic
organisms in Monera and Protista) termed the producers, and rest at the
base of all food webs. A food web is an ecological concept to trace energy
flow through an ecosystem. Economically, this kingdom is unparalleled,
with agriculture providing billions of dollars to the economy (as well as
the foundation of "civilization"). Food, building materials,
paper, drugs (both legal and illegal), and roses, are plants or
plant-derived products. |
