Microbiology Procedure

Index >> Microorganisms Types >> Plantae and Animalia

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Microorganism Types Plantae and Animalia Protists Eukaryotes and Prokaryotes Primary Subdivisions of Cellular Organisms Monera Main Groups of Microorganisms Bacteria Actinomycetes Protozoa Algae Fungi Viruses Microbial Classification Approaches Artificial Approach Natural Approach

Plantae and Animalia

	Plantae and Animalia - In the early 19th century the microorganisms were fitted into the traditional two kingdoms of organisms, the Animalia and the Plantae. This assignment of the microbes to either kingdom was made on the basis of the most easily determinable differences between animals and plants: ability of active movement and the ability to photosynthesise. Algae (immobile, photosynthetic) were grouped under plants. Fungi were also lumped with the plants. Microscopic motile forms (including protozoa and bacteria) were lumped together as one group, the Infusoria under animals.
However, about 1840 biologists perceived that the Infusoria were a very heterogeneous group in terms of their cellular organisation. The simpler, unicellular forms, were, therefore, subdivided into two groups: the protozoa with relatively large and complex cells, and the bacteria with much smaller and simple cells. The old Infusoria was thus split into three groups: (1) metazoa (multicellular) invertebrate animals, (2) protozoa (unicellular) animals, and
(3) Bacteria, that were transferred to plants. This Procrustean distribution of microorganisms into plants and animals presented too many inconsistencies. More information became available on microorganisms, that hardly justified their inclusion in either kingdoms. For instance, unlike plants fungi and most bacteria are non photosynthetic. Many bacteria are motile, and some fungi and algae have motile Sports. It was thus felt that division of living world into these two kingdoms can no longer be maintained.

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Phylogenetic Approach Adansonian Approach - Numerical Taxonomy Macromolecular Approach DNA Base Composition DNA Base Compositions of Representative Bacteria Constancy of G+C content in Strains of Bacteria Nucleic Acid Hybridization Classification of Bacteria from Bergey's Manual of Determinative Bacteriology

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