Which of the following are classified as non-living particles?

Viruses are classified as non-living particles primarily because they do not possess the characteristics of living organisms. They lack cellular structure, cannot reproduce on their own, and require a host cell to replicate. Viruses consist of genetic material (either DNA or RNA) encased in a protein coat, and they do not carry out metabolic processes independent of a host. This lack of independent biological functions places them in the category of non-living entities, distinguishing them from living microorganisms like bacteria, fungi, and protozoa, which have cellular organization, metabolic activity, and the ability to reproduce independently. Understanding this classification helps clarify the fundamental differences between living and non-living biological entities.