Monera
"Procaryotic cells which lack a nuclear envelope, plastids and mitochondria, and 9-plus-2 flagella. Monera are unicellular but sometimes aggregate into filaments or other superficially multi-cellular bodies. Their predominant mode of nutrition is absorption, but some groups are photosynthetic or chemosynthetic. Reproduction is primarily asexual, by fission or budding, but portions of DNA molecules may also be exchanged between cells under certain circumstances. They are motile by simple flagella, gliding, or nonmotile.
About 1,600 species of bacteria and bacterialike organisms are recognized at present, but doubtless thousands more await discovery. The recognition of species is not comparable with that in eucaryotes, and is based largely upon metabolic features.
One group, the class Rickettsiae-very small bacterialike organisms-occurs widely as parasites in arthropods, and may contain tens or even hundreds of thousands of species, depending upon the criteria used; they have not been included in the estimate given. No satisfactory classification of the Monera has yet been proposed. One of the included groups is the phylum Cyanophyta, the blue-green algae, with motility by gliding and photosynthesis based on chlorophyll a. Although some 7,500 species have been described, a more reasonable estimate puts the total number of these specialized bacteria at about 200 nonsymbiotic distinct species."
Source: Biology of Plants, Fourth Edition, Worth Publishers Inc., Stanford University, Peter H. Raven and Helena Curtis, ©1971
| Taxonomic Hierarchy | |
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| Kingdom | Monera – monerans |
| Direct Children: | |
| Phylum | Bacteria – bacteria, bactéries |
| Phylum | Cyanophycota – blue-green algae, cyanophytes |
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