Why do scientists consider viruses as nonliving?

Is it because their metabolic activity is borrowed from the host cell? They're unable to reproduce? They have no genes? I'm really confused.

Why do scientists consider viruses as nonliving?nortonantivirus

Because without a host cell, they cannot survive or, cause illness. They have no cells. Viruses are a sub-microscopic infectious agent that are unable to grow or reproduce outside a host cell. They are considered non-living as they do not meet the criteria of the definition of life.

Why do scientists consider viruses as nonliving?spyware

Virus consider as non living b/c virus can not reprpduce itself but it reproduce with host.It is main point that virus consider as non living.Virus have gene(DNA or RNA).Virus absoulatly depended upon host cell.Due all of virus activities virus consider as non living.
They do not contain the capacity to live on their own. They are essentialy obligate intracellular parasites and do not contain the ability to replicate on their own. They contain genetic material (DNA or RNA, depending on the virus) that encodes for viral proteins, but they require cellular machinery to transcribe and translate proteins, replicate the viral genetic material, and assemble new virions.

They DO have genes. They CAN reproduce, but again, they require host cellular machinery to do so. They cannot replicate on their own. A BIG categorical reason they are not 'alive' per se is that they have no metabilic machienry of their own, so outside of the host cell, they do nothing. They do not respirate, they do not have any metabolic machinery active for generating any ATP or any other metabolite. They are essentially static until they enter a host cell.
They don't exibit the traits of life until they occupy a host.
I seem to recall going over a sort-of checklist of things an organism needs to be alive. I found one online that might help. It is not true that viruses have no genes. They certainly do have both genes and a genome which is their own. One of the reasons that viruses are considered non-living is that they can not replicate on their own. They require at least some proponents of the host cell machinery to do so. Energy generated by the host cell is needed by these viruses because replication requires a lot of energy.

When you look at this site, notice that viruses do have some of the qualities listed as conventional characteristics of life. They are certainly organized, and also proliferate and adapt. Viruses have the capacity to change over time to promote their own proliferation.

I think that some people argue that all the features in the list absolutely need to be present for an individual to be defined as living. Since viruses don't technically fit under every category, they are considered to be non-living. But others argue that maybe this list needs to be revised, or that we can't just lump together a bunch of definitions to describe life on earth.