After the new classification of living organisms into three domains of life (bacteria, archaea and eukarya) which one of the following is true about archaea?

Archaea ____________

The correct option is: have some novel features that are absent in other eukaryotes and prokaryotes.

To understand why this statement is correct, let us look at the key biochemical and structural characteristics of the domain Archaea:
1. Unique Cell Membrane Lipids: One of the most distinctive features of Archaea is their membrane chemistry. Their cell membranes are composed of branched-chain hydrocarbons attached to glycerol by ether linkages. In contrast, both Bacteria (prokaryotes) and Eukarya (eukaryotes) have membranes made of unbranched fatty acids attached to glycerol by ester linkages. This unique ether linkage helps Archaea survive in extreme environments.
2. Distinct Cell Wall Structure: Unlike bacteria, archaeal cell walls do not contain peptidoglycan. Instead, they are composed of unique proteins, glycoproteins, or pseudopeptidoglycan.
3. Shared and Distinct Biology: Archaea are prokaryotic in terms of their physical structure (lacking a membrane-bound nucleus and organelles), but their genetic and metabolic pathways (such as transcription and translation machinery) are much closer to eukaryotes. Because they share some traits with bacteria and others with eukaryotes, they do not "completely differ" from either domain, nor do they "resemble eukarya in all respects."

Thus, the presence of these unique biochemical and molecular signatures confirms that Archaea possess novel features not found in any other prokaryotes or eukaryotes.