Changes

==Origin==

==Origin==

plural of ''bacterium''

plural of ''bacterium''

*[http://en.wikipedia.org/wiki/19th_century 1881]

*[https://en.wikipedia.org/wiki/19th_century 1881]

==Definitions==

==Definitions==

*1: any of a [[domain]] (Bacteria) of [http://en.wikipedia.org/wiki/Prokaryotic prokaryotic] round, spiral, or rod-shaped single-[[cell]]ed microorganisms that may lack cell walls or are gram-positive or gram-negative if they have cell walls, that are often [[aggregated]] into colonies or motile by means of flagella, that typically live in [[soil]], [[water]], organic matter, or the bodies of [[plants]] and animals, that are usually autotrophic, saprophytic, or [[parasitic]] in nutrition, and that are noted for their [[biochemical]] [[effects]] and pathogenicity

*1: any of a [[domain]] (Bacteria) of [https://en.wikipedia.org/wiki/Prokaryotic prokaryotic] round, spiral, or rod-shaped single-[[cell]]ed microorganisms that may lack cell walls or are gram-positive or gram-negative if they have cell walls, that are often [[aggregated]] into colonies or motile by means of flagella, that typically live in [[soil]], [[water]], organic matter, or the bodies of [[plants]] and animals, that are usually autotrophic, saprophytic, or [[parasitic]] in nutrition, and that are noted for their [[biochemical]] [[effects]] and pathogenicity

==Description==

==Description==

'''Bacteria''',  singular: bacterium) are a large [[domain]] of [http://en.wikipedia.org/wiki/Prokaryotic prokaryotic] microorganisms. Typically a few micrometres in length, bacteria have a wide range of [[shape]]s, ranging from [[spheres]] to rods and [[spiral]]s. Bacteria are present in most [[habitats]] on [[Earth]], growing in soil, acidic hot springs, radioactive waste, water, and deep in the [http://en.wikipedia.org/wiki/Crust_(geology) Earth's crust], as well as in organic matter and the live bodies of plants and animals, providing outstanding examples of [http://en.wikipedia.org/wiki/Mutualism_(biology) mutualism] in the digestive tracts of humans, termites and cockroaches. There are typically 40 million bacterial cells in a gram of [[soil]] and a million bacterial cells in a millilitre of [http://en.wikipedia.org/wiki/Fresh_water fresh water]; in all, there are approximately five nonillion (5×1030) bacteria on Earth, forming a [http://en.wikipedia.org/wiki/Biomass_(ecology) biomass] that exceeds that of all plants and animals. Bacteria are [[vital]] in [[recycling]] nutrients, with many steps in nutrient [[cycles]] depending on these [[organisms]], such as the fixation of nitrogen from the [[atmosphere]] and [http://en.wikipedia.org/wiki/Putrefaction putrefaction]. In the biological communities surrounding hydrothermal vents and cold seeps, bacteria provide the nutrients needed to sustain life by converting dissolved compounds such as [http://en.wikipedia.org/wiki/Hydrogen_sulphide hydrogen sulphide] and [http://en.wikipedia.org/wiki/Methane methane]. Most bacteria have not been characterised, and only about half of the phyla of bacteria have [[species]] that can be grown in the [[laboratory]]. The study of bacteria is known as [http://en.wikipedia.org/wiki/Bacteriology bacteriology], a branch of [http://en.wikipedia.org/wiki/Microbiology microbiology].[http://en.wikipedia.org/wiki/Bacteria]

'''Bacteria''',  singular: bacterium) are a large [[domain]] of [https://en.wikipedia.org/wiki/Prokaryotic prokaryotic] microorganisms. Typically a few micrometres in length, bacteria have a wide range of [[shape]]s, ranging from [[spheres]] to rods and [[spiral]]s. Bacteria are present in most [[habitats]] on [[Earth]], growing in soil, acidic hot springs, radioactive waste, water, and deep in the [https://en.wikipedia.org/wiki/Crust_(geology) Earth's crust], as well as in organic matter and the live bodies of plants and animals, providing outstanding examples of [https://en.wikipedia.org/wiki/Mutualism_(biology) mutualism] in the digestive tracts of humans, termites and cockroaches. There are typically 40 million bacterial cells in a gram of [[soil]] and a million bacterial cells in a millilitre of [https://en.wikipedia.org/wiki/Fresh_water fresh water]; in all, there are approximately five nonillion (5×1030) bacteria on Earth, forming a [https://en.wikipedia.org/wiki/Biomass_(ecology) biomass] that exceeds that of all plants and animals. Bacteria are [[vital]] in [[recycling]] nutrients, with many steps in nutrient [[cycles]] depending on these [[organisms]], such as the fixation of nitrogen from the [[atmosphere]] and [https://en.wikipedia.org/wiki/Putrefaction putrefaction]. In the biological communities surrounding hydrothermal vents and cold seeps, bacteria provide the nutrients needed to sustain life by converting dissolved compounds such as [https://en.wikipedia.org/wiki/Hydrogen_sulphide hydrogen sulphide] and [https://en.wikipedia.org/wiki/Methane methane]. Most bacteria have not been characterised, and only about half of the phyla of bacteria have [[species]] that can be grown in the [[laboratory]]. The study of bacteria is known as [https://en.wikipedia.org/wiki/Bacteriology bacteriology], a branch of [https://en.wikipedia.org/wiki/Microbiology microbiology].[https://en.wikipedia.org/wiki/Bacteria]

[[Category: Biology]]

[[Category: Biology]]