Answer:
Step-by-step explanation:
Archaea, Eubacteria and Eukarya are three or Eukaryota are the three domains classified by Carl Woese (1977). In the earlier systems of classifications, Archaea were included in the Kingdom Monera along with true bacteria (Eubacteria) and Cyanobacteria (blue-green algae) based on some similarities such as they both are prokaryotes.
But now it is certain that Archaea possess distinct difference from eubacteria in their cellular structures such as archaea to have only one type of RNA polymerase enzyme whereas, eubacteria possess several types of RNA polymerase enzyme and metabolic activities. Eukarya are eukaryotes having true nucleus. Archaea have a unique and separate evolutionary ancestry as well.