Categories of Organisms

1- System Two kingdoms: the first organization kingdoms is due to Aristotle who distinguished all living entities of nature into two kingdoms: plants and animals. The first characterized by having "vegetative soul" which gives reproduction, growth and nutrition; the second additionally has "sensitive soul" which gives addition to the above perception, desire and movement.

Linnaeus also distinguished these two kingdoms of living things and also treated minerals, placing them in a third kingdom, Lapides. It also introduced the binomial nomenclature to refer to species and kingdoms divided into classes, classes into orders, orders into families, families into genera and species genera.

2- System Three Kingdoms: in 1858 R. Owen noted the difficulty of classifying microbial plant and animal beings, he suggested creating the kingdom Protozoa and defined as tiny beings mostly formed by nucleated cells.

In 1860 the English biologist John Hogg, posits the third kingdom, called "Regnium primigenium" or Protoctista for protozoa, protófitos and simple shapes. Hogg actually spoke of four kingdoms: animal, vegetable, and mineral primal.

In 1866 Ernst Haeckel called the third kingdom Protista and defined it as the "primordial" the kingdom of early and intermediate forms between Animal and Plantae kingdoms. Acknowledged the problem of classification by the presence of animal characters, and mixed vegetables, but necessary for systematic purposes. He was the first to distinguish between unicellular organisms (protists) and multicellular (plants and animals).

3- System Four kingdoms: the concept of the third kingdom was questioned by Otto Bütschli in the 1880s, as it was considered to Protista as polyphyletic, especially the inclusion of bacteria.

Herbert Copeland in its publications separates nucleated protists bacteria in the system enucleated following four kingdoms: Plantae (or Metaphyta), Animalia (or Metazoa), Protoctista (or Protista) and Mychota (or Monera) for bacteria and viruses.

4- System Five Kingdoms: Robert Whittaker recognized an additional kingdom of fungi (Fungi). The result was the system of the 5 kingdoms, proposed in 1969. It is based mainly on differences in nutrition: Plantae are mostly multicellular autotrophs, heterotrophs Animalia and Fungi multicellular multicellular saprophytes. The other two kingdoms, Protista and Monera (prokaryotes) include unicellular or colonial organisms.

5- System Six Kingdoms: Carl Woese and Fox G. divided in 1977 moneras prokaryotes or two super-kingdoms Eubacteria and Archaea. In 1990, Woese renamed the new groups so ran the system consists of three domains Bacteria, Archaea and Eucarya.

These two prokaryotic groups Archaea (or Archaebacteria) and Bacteria (or Eubacteria), are considered kingdoms along with plants, animals, fungi and protists, which is the system of six realms, a system that has become standard.

The kingdoms have the following characteristics:

-Bacteria: are the most abundant creatures on the planet, with a variety of habitats and metabolisms. found in all terrestrial and aquatic habitats; grow up in the most extreme and hot springs and acidic waters, radioactive waste and in the depths of both the sea and the earth's crust.

-Archaea: are a group of unicellular prokaryotic microorganisms morphology (coreless or internal membranous organs).

-Protista: are the simplest eukaryotes, form a group consisting of protozoans, algae and slime molds.

-Plantae: photosynthetic beings are living without locomotor ability and whose cell walls are composed mainly of cellulose; is comprised of land plants and algae that relate to them.

-Fungi: is a group of eukaryotic organisms among which are the molds, yeasts and mushrooms.

-Animalia: are a major group of eukaryotic organisms, heterotrophic, multicellular tissue. They are characterized by their capacity for locomotion, the absence of chlorophyll and wall in their cells, and embryonic development, passing through a blastula stage and determines a fixed body plan.