Viruses exist in an ambiguous state between living and non-living. They consist of nucleic acid wrapped in protein and require a host cell to replicate, perform metabolic functions, and survive. While viruses do not meet all the standard criteria for classifying something as living, certain giant viruses like the Mimivirus challenge this classification and show traits more similar to living organisms. Viruses are most similar to parasites in their need for a host cell but differ in that viruses cannot self-replicate without one.

1. Are viruses living?

3. Qualifications of Living Organism x= Needs a host cell to perform these functions X x x x x X Virus X X X X X X Organism Evolution Metabolism Homeostasis Growth Reproduction Responds to Stimuli Living Organism vs. Virus

6. Questions?