Which entity has no cell wall, no plasma membrane, nor any organelles - it only has nucleic acid and proteins?

Which entity has no cell wall, no plasma membrane, nor any organelles - it only has nucleic acid and proteins?

• A. Virus
• B. Bacteria
• C. Fungus
• D. Protozoa

Answer: (A)

A virus is an acellular particle that is made only of nucleic acid and a protein coat, and sometimes a lipid envelope. It lacks a cell wall, a true plasma membrane, and any cellular organelles, so it cannot carry out metabolic processes on its own and must hijack a host cell to replicate. That combination—no cellular boundaries or internal compartments, just genetic material and proteins—best fits the description. In contrast, bacteria, fungi, and protozoa are cellular organisms with membranes, walls (in many cases), and internal organelles, so they don’t match the scenario.

A virus is an acellular particle that is made only of nucleic acid and a protein coat, and sometimes a lipid envelope. It lacks a cell wall, a true plasma membrane, and any cellular organelles, so it cannot carry out metabolic processes on its own and must hijack a host cell to replicate. That combination—no cellular boundaries or internal compartments, just genetic material and proteins—best fits the description. In contrast, bacteria, fungi, and protozoa are cellular organisms with membranes, walls (in many cases), and internal organelles, so they don’t match the scenario.