·methanogens ·extreme halophiles ·lack a nucleus and cell organelles ·cell walls do not contain peptidoglycan these characteristics describe organisms found in the domain a) archaea. b) bacteria. c) eukarya. d) monera.

The correct answer is - A) Archaea.

Explanation:

Archaea is the domain that comprises the unicellular prokaryotic organisms. Archaea domain members lack a true nucleus and membrane-bound organelles like mitochondria or the chloroplast.

The cell wall of these domains lacks the peptidoglycan in their cell wall which distinguishes them from bacteria which is the characteristic feature of the bacteria cell wall. Archaea members can survive in extreme conditions such as the highest temperatures or the extreme saline conditions and characterized as halophiles. These organisms produce methane and by-products of the methane hence called Archaea.

Thus, the correct answer is - A) Archaea.