The topic of whether viruses are dead, or living, organisms, is pretty much up for debate. Given that there are 8 specific characteristics that would categorize an organism as living, or non-living, and seeing as viruses seem to meet some of these characteristics, but not others, scientists are still not able to define that a virus is definitely dead, or alive. All they know for sure is that a virus is an organism that is comprised of genetic material and a capsule that protects that material, that it uses certain mechanisms to infect a host cell to use it for its survival purposes, and that it can adapt to environmental conditions.
First, lets analyze the 8 criteria that science takes into account to suppose an organism is alive or not, and apply it to viruses. The first criteria is organization. In the case of viruses, these organisms are organized enough that they are not just genetic material on the loose; they have protective barriers and mechanisms that will allow the virus not just to identify a host cell, but also penetrate it and use it in its favor. Second, we have that a living organism must be able to reproduce. In the case of viruses there is still uncertainty on this point. Science knows viruses replicate their genetic material with the help of the cell, and then daughter virions are produced, but not all scientists agree that viruses actually reproduce. They certainly multiply. Third, we have that living organisms maintain homeostasis. In this case viruses fail miserably as all they do is literally infect, be replicated and kill their host. They are not capable of controlling their environmental conditions and are totally dependent on their host. Fourth, we have that living things grow. Viruses do not grow at all. Virions are simply exact replicas of their original virus. Next we have the use of energy. Although still not decided, it seems that viruses take advantage of the energy of the host cell, but it is uncertain if they themselves are capable of producing any energy, or using energy without a host. Then we have response to stimuli. Viruses do not respond at all to this. They are simply programmed to infect and replicate, but if they are stimulated, the process of reaction does not change in the least, like it would happen with bacteria or fungi. Living organisms possess genetic material, and on this point is where most scientists disagree on whether viruses are alive or not, because these organisms do have genetic material. Finally, the eighth characteristic of living organisms is that they adapt and evolve. On this point, viruses also get a passing score. They are able to remain dormant, and stable, even if conditions change, and they will adapt perfectly to new conditions as well, becoming active once more.
So in the end, can we say that viruses are alive? Well, if we look it from several of the characteristics of life, then yes, we would have to say so. Viruses have genetic coding, they replicate, they are organized and they adapt. However, they do not respond to stimuli, their only point is to replicate and kill their host, they depend entirely on host cells to be able to carry out their funtion, so in this case, we would definitely say that viruses are not living organisms.
