The karyomastigont, an organellar system that includes the nucleus, the nuclear connector, and kinetosome-centrioles in many protoctist
and animal cells, is a conspicuous component of the cytoskeleton.
Kingdom (0761418180), Reptile Class (0761418202), Insect Class (0761418199), Flowering Plant Kingdom (0761418172) and Primate Order (0761-418164) by Stefoff each survey kingdoms and species, classification methods, physical traits, adaptations, and life cycles.
Nearly one in five species in the fungal kingdom forms a composite with an alga, which is from the protist, or protoctist
Kala-azar, or visceral leishmaniasis, is caused by the presence in the blood and some organs, such as liver, spleen, and bone marrow, of the parasitic kinetoplastid protoctist
Leishmania donovani, which is transmitted by the bite of a sandfly Phlebotomus.
In particular, the role of the microheterotrophs, protoctist
microorganisms that feed on microalgae and bacteria, may be of great importance in the food webs of the Antarctic Ocean.
Although bacteria can exchange genetic material and unicellular protoctists
can merge to form larger cells, in neither of these cases is the exchange of genes necessary for reproduction to occur.
As Case noted, attempted reconciliation of five Kingdoms (Bacteria, Protoctists
, Animals, Plants, Fungi) with three Domains (Bacteria, Archaea, Eucarya) resulted in a "compromise" of six kingdoms (Archaebacteria, Eubacteria, Protista, Fungi, Plantae, Animalia)--an outcome that does not fully represent the intent of either the five-kingdom or three-domain system.
Anthropogenic Natural Unintentional Gas-to-particle conversions Internal combustion engines Forest fires Power plants Volcanoes (hot lava) Incinerators Viruses Jet engines Biogenic magnetite: magnetotactic Metal fumes (smelting, bacteria protoctists
, mollusks, welding, etc.
The five kingdoms system identifies five categories of organisms as rational kingdom divisions: bacteria (the prokaryotic or nucleus-lacking microbes), protoctists
(algae, slime molds, and other nucleated eukaryotic organisms formed by symbiosis from bacteria), fungi (mushrooms, molds, and yeasts, all of which reproduce by spores), plants (organisms that develop from spores and embryos retained by the mother's tissue), and animals (organisms that develop from eggs fertilized by sperm).
, and bacteria], animals may be defined as multicellular,
For decades, most biologists accepted the classification of all life into five kingdoms: Bacteria (or Monera), Protoctists
(protists and their macroscopic relatives), Animals, Plants, and Fungi (Figure 1).
Only some forms of bacteria, some protoctists
(all are algae), and plants can perform photosynthesis.