Bacteria Bacteria Bacteria (; common noun bacteria, singular bacterium) are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep portions of Earth's crust. Bacteria also live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, and only about half of the
International Code of Nomenclature for algae, fungi, and plants International Botanical Congress have produced revised versions of these "Rules", later called the "International Code of Botanical Nomenclature", and then "International Code of Nomenclature for algae, fungi, and plants". The Nomenclature Section of the 18th International Botanical Congress in Melbourne, Australia (2011) made major changes: Some important versions are listed below. Specific to botany More general International Code of Nomenclature for algae, fungi, and plants The International Code of Nomenclature for algae, fungi, and plants (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups