Changes

2,486 bytes added ,  20:35, 12 June 2010
Created page with 'File:lighterstill.jpgright|frame A '''microorganism''' (from the Greek: μικρός, mikrós, "small" and ὀργανισμός, organismós, "[[o...'
[[File:lighterstill.jpg]][[File:Microbes.jpg|right|frame]]

A '''microorganism''' (from the [[Greek]]: μικρός, mikrós, "small" and ὀργανισμός, organismós, "[[organism]]"; also spelled micro organism or micro-organism) or microbe is an organism that is microscopic (too small to be seen by the naked [[human]] eye). The [[study]] of microorganisms is called [http://en.wikipedia.org/wiki/Microbiology microbiology], a subject that began with [http://en.wikipedia.org/wiki/Anton_van_Leeuwenhoek Anton van Leeuwenhoek]'s [[discovery]] of microorganisms in 1675, using a [http://en.wikipedia.org/wiki/Microscope microscope] of his own [[design]].

Microorganisms are very [[diverse]]; they include [http://en.wikipedia.org/wiki/Bacteria bacteria], fungi, archaea, and protists; microscopic plants (green algae); and [[animals]] such as [http://en.wikipedia.org/wiki/Plankton plankton] and the planarian. Some microbiologists also include [http://en.wikipedia.org/wiki/Virus viruses], but others consider these as non-living. Most microorganisms are unicellular (single-[[cell]]ed), but this is not [[universal]], since some multicellular [[organisms]] are microscopic, while some unicellular protists and bacteria, like [http://en.wikipedia.org/wiki/Thiomargarita_namibiensis Thiomargarita namibiensis], are macroscopic and visible to the naked eye.

Microorganisms live in all parts of the [[biosphere]] where there is liquid [[water]], including [[soil]], hot springs, on the [[ocean]] floor, high in the [[atmosphere]] and deep inside rocks within the [[Earth]]'s crust. Microorganisms are critical to [[nutrient]] recycling in [[ecosystems]] as they act as [http://en.wikipedia.org/wiki/Decomposer decomposers]. As some microorganisms can fix nitrogen, they are a [[vital]] part of the [http://en.wikipedia.org/wiki/Nitrogen_cycle nitrogen cycle], and recent [[studies]] indicate that airborne microbes may play a role in precipitation and [[weather]].

Microbes are also exploited by people in [http://en.wikipedia.org/wiki/Biotechnology biotechnology], both in [[traditional]] [[food]] and beverage [[preparation]], and in modern [[technologies]] based on [[genetic engineering]]. However, [http://en.wikipedia.org/wiki/Pathogenic_microbes pathogenic microbes] are harmful, since they invade and [[grow]] within other organisms, causing [[diseases]] that kill people, other [[animals]] and [[plants]].[http://en.wikipedia.org/wiki/Microbes]

[[Category: Biology]]