Virus

There is no precise definition of what separates the living from the non-living. One definition might be the point at which an entity becomes self-aware. In this sense, someone who has had severe head trauma may be classified as brain dead. In this case, the body and brain are still functioning on a base level and there is definitely metabolic activity in all of the cells that make up the larger organism, but it is presumed that there is no self-awareness so the person is classified as brain dead. On the other end of the spectrum, a different criterion for defining life would be the ability to move a genetic blueprint into future generations, thereby regenerating your likeness. In the second, more simplistic definition, viruses are definitely alive. They are undeniably the most efficient entities on this planet at propagating their genetic information.

Although there is no definitive resolution to the question of whether viruses can be considered living entities, their ability to pass on genetic information to future generations makes them major players in an evolutionary sense.

The simplest answer is: "That depends".1 I don't mean to be flippant but that recognises how much of the definition of a word like "life" comes from personal perspective. There is no real wrong or right here . You make your case for why you think it is or is not alive, and that's your position. Cool. However we tend to yield to more objective facts though, and just say "No, they are not". At best, viruses could be considered undead (they are not dead because that would imply they were once alive). No zombie parallels please-they don't eat brains...although there are some....later!

Another argument is that viruses should not be added to the tree of life...even the big viruses...but then the concept of a tree of life may be outdated as well2,3.

So, back to some virology. A virus can not make more of itself, or multiply, without help from the contents of living cells (lets leave