Why are viruses not considered alive in terms of how they reproduce?
Viruses are not considered alive because they are unable to reproduce on their own. While they can replicate and multiply inside a host cell, they lack the necessary cellular machinery to independently reproduce.
Unlike cells, which can carry out metabolic processes, grow, and divide, viruses are acellular entities that rely entirely on host cells for their reproduction. They hijack the host's cellular machinery to replicate their genetic material and produce new virus particles. In doing so, viruses essentially "take over" the host's cellular functions and forcefully redirect them towards viral replication.
Since viruses are completely dependent on host cells for their reproduction and lack independent cellular structures and metabolic activities, they are not classified as living organisms. However, they exhibit certain characteristics of life, such as the ability to evolve and adapt to their environment, as well as the capability to cause infection and disease.