why are viruses not conciderd living things?

Question

help

Answer 1

The primary argument is that viruses are incapable of living outside of their host. Interestingly, this is true of many bacteria and some fungi as well. Most virologists will tell you that viruses are alive and meet all the important criteria of life:

There are 7 characteristics of life: homeostasis, organization, metabolism, growth, adaptation, response to stimuli, and reproduction.

Homeostasis - many bacteria don't maintain a stable internal environment, are they dead?

Organization - Viruses are organized, have you ever seen a crystal structure of a virion

Metabolism - no

Growth - yes virus particles grow and mature in the host cell

adaptation (evolution) - very much yes

response to stimuli - Viruses respond to stimuli, just not the stimuli you think of naturally. Viruses modulate their reproduction and life cycles based on the "stimuli" in the host cell

Reproduction - Of course yes. Of course they reproduce and pass on their genes. And nearly all viruses encode their own replication proteins.

So the only characteristic that viruses fail to qualifiy as alive for is metabolism, and it could easily be argued that metabolism is the least important and most arbitrar characteristic of living organisms since viruses do a fine job of gathering energy from their environment (host cell). Some folks can't get over this arbitrary criteria so they refuse to give the idea any thought.

Answer 2

I think it depends on your source. Some areas do certainly consider viruses as living organisms.

Answer 3

No metabolism. They do not independently have the ability to synthesize the macromolecules of which they are composed.

If this is for a homework or test question, you may want to add that they do not reproduce independently either.

Answer 4

because they only function when they are living inside a host, they cant live by themselves

Answer 5

they do not have the characterisitcs of life, such as being composeed of cells, or reproducing on thier own