Status of Viruses:

Viruses are acellular i.e. they do not possess cellular organization yet show some characteristics of living. Viruses are infectious entities that contain either RNA or DNA, normally encased in a protein coat, and reproduce only in living cells, where they cause several diseases. They are not considered organisms and thus are not included in the five-kingdom classification system. Prions and viroids are also acellular particles and are not included in the five-kingdom classification system.