Unicellular microorganisms belong to the Archaea domain, which are genetically different from bacteria and eukaryotes and frequently live in harsh environments.
Supplement Halophiles (microorganisms that can live in highly saline conditions), methanogens (microorganisms that generate methane), and thermophiles are all examples of archaebacteria (microorganisms that can thrive in extremely hot environments).
They developed independently of eukaryotes and eubacteria.
They are prokaryotes that lack a specific cell nucleus, comparable to eubacteria.
In terms of ribosomal structure, intron presence, and membrane structure or composition, they differ.
In some aspects, archaea are comparable to eukaryotes in that they have genes and metabolic pathways that are more closely linked to those of eukaryotes, particularly enzymes involved in transcription and translation.
Word origin: New Latin, from Greek arkhaion, neuter singular of arkhaios, ancient + bacteria.