Final answer:
Archaeal cells differ from bacterial cells chiefly in their cell wall composition, which lacks peptidoglycan, and their membrane structure, featuring ether-bonded isoprene chains instead of ester-bonded fatty acids.
Step-by-step explanation:
The distinctly different features of archaeal cells compared to bacterial cells pertain to various components. Here are the differences:
- Cell wall composition: Archaeal cell walls do not contain peptidoglycan, unlike bacterial cell walls which do.
- Membrane structure: The plasma membranes of archaea are composed of ether linkages with branched isoprene chains, distinct from the bacterial membranes which have ester linkages with unbranched fatty acids.
- Ribosomes: There's a common misconception about ribosomes because archaea actually have ribosomes that are functionally more similar to eukaryotic ribosomes and should not be categorized under 70S or 80S. Instead, they share properties with eukaryotic ribosomes which differ from those in bacterial cells.
Given this information, the correct answers are B) Cell wall composition and D) Membrane structure. Option C, DNA structure, is not necessarily different, as the DNA of both archaea and bacteria is typically circular. While the given reference incorrectly portrays the size of archaeal ribosomes in comparison to bacterial ribosomes, it is important to clarify that archaeal ribosomes are not defined by the 70S/80S distinction.