Question

which is a characteristic of archaea, but not bacteria or eukarya?
ether - linked membrane lipids
cell walls with peptidoglycan
plasmids
nitrogen fixation
chlorophyll - based photosynthesis

Explanation:

Archaea have ether - linked membrane lipids, which is a unique characteristic not found in Bacteria or Eukarya. Bacteria have cell walls with peptidoglycan, plasmids can be present in bacteria, nitrogen fixation occurs in some bacteria, and chlorophyll - based photosynthesis is seen in plants (Eukarya) and some bacteria.

Answer:

Ether - linked membrane lipids