An organism is observed to be unicellular and lacks a nuclear membrane. Further analysis reveals that it completely lacks a cell wall and is among the smallest known living cells. Which of the following groups does this organism belong to?

Step-by-step solution

The absence of a nuclear membrane indicates that the organism is a prokaryote, which eliminates slime moulds as they are eukaryotic protists. Among prokaryotes, Mycoplasma are unique because they completely lack a cell wall. They are also recognized as the smallest living cells known. Archaebacteria and cyanobacteria are prokaryotes, but they both possess a cell wall. Therefore, the described organism belongs to Mycoplasma. Answer: Mycoplasma