Viruses have some characteristics of life (they replicate and evolve), but they don't have any metabolic processes and can't exist independently, so they're usu

Viruses have some characteristics of life (they replicate and evolve), but they don't have any metabolic processes and can't exist independently, so they're usually not considered "alive" in the same way cells are. They don't grow, they don't have a life cycle, they don't consume or expend energy, or do anything on their own, really. They're merely (quite mechanical) clumps of self replicating generic material.