Editing Three-domain system (section)

===Domain Bacteria===
The [[Bacteria]] are also [[prokaryotic]]; their domain consists of cells with bacterial rRNA, no nuclear membrane, and whose membranes possess primarily ''diacyl glycerol diester lipids''. Traditionally classified as bacteria, many thrive in the same environments favored by humans, and were the first prokaryotes discovered; they were briefly called the '''Eubacteria''' or "true" bacteria when the Archaea were first recognized as a distinct [[clade]].

Most known pathogenic prokaryotic organisms belong to bacteria (see<ref name="Eckburg">{{cite journal |last1=Eckburg |first1=Paul B. |last2=Lepp |first2=Paul W. |last3=Relman |first3=David A. |year=2003 |title=Archaea and their potential role in human disease |journal=Infection and Immunity |volume=71 |issue=2 |pages=591–596 |doi=10.1128/IAI.71.2.591-596.2003 |pmid=12540534 |pmc=145348}}</ref> for exceptions). For that reason, and because the Archaea are typically difficult to grow in laboratories, Bacteria are currently studied more extensively than Archaea.

Some examples of bacteria include:
* "[[Cyanobacteria]]" – photosynthesizing bacteria that are related to the chloroplasts of eukaryotic plants and algae
* [[Spirochaetota]] – [[Gram-negative]] bacteria that include those causing syphilis and Lyme disease
* [[Actinomycetota]] – [[Gram-positive]] bacteria including ''[[Bifidobacterium animalis]]'' which is present in the human large intestine