archaea

¹ American  

[ahr-kee-uh] / ˈɑr ki ə /

plural noun

Microbiology.

singular

archaeon

1. a group of microorganisms, including the methanogens and certain halophiles and thermoacidophiles, that have RNA sequences, coenzymes, and a cell wall composition that are different from all other organisms: considered to be an ancient form of life that evolved separately from bacteria and algae and classified as constituting the domain Archaea.

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Archaea ² American  

[ahr-kee-uh] / ˈɑr ki ə /

noun

(used with a singular or plural verb)

1. (in the three-domain system of classification) the taxonomic domain comprising the archaea.

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Etymology

Origin of archaea¹

First recorded in 1985–90; from New Latin, from Greek archaîa, neuter plural of archaîos “ancient”; archaeo- ( def. )

Origin of Archaea²

First recorded in 1990–95; from New Latin; archaea ( def. )

Example Sentences

Earlier studies tested the idea that perhaps the carbon-fixing archaea were far more efficient than scientists assumed, needing less nitrogen to fix the same amount of carbon.

From Science Daily

Their results indicated that despite inhibiting these ammonia oxidizers -- mostly archaea that are abundant in the dark ocean -- the rate of carbon fixation in the study areas didn't drop as much as expected.

From Science Daily

If ammonia-oxidizing archaea are not responsible for as much carbon fixation as once believed, other microbes must be stepping in.

From Science Daily

The pool of likely contributors now includes additional types of microbes in the surrounding community, particularly bacteria and some archaea.

From Science Daily

"The Earth is approximately 4.5 billion years old, with the first microbial life forms appearing over 4 billion years ago. These organisms consisted of two groups -- bacteria and the distinct but related archaea, collectively known as prokaryotes," said co-author Anja Spang from the Department of Microbiology & Biogeochemistry at the Royal Netherlands Institute for Sea Research.

From Science Daily