Give three reasons why viruses can be considered not alive?

2602>They can't survive without a host, and they don't have cells. Sorry, I can't think of a 3rd one right now.
Reply:If they are dead. All viruses are alive though. If they are dead then they are not viruses anymore.
Reply:http://www.beyondbooks.com/lif72/2c.asp
Reply:thats confusing?
Reply:Someone responding to this post doesn't know about the controversy.





-They do not all have DNA. Some viruses have only RNA.


-They don't technically reproduce. They take over other cell's reproductive "machinery" if you will to reproduce.


-Do they REALLY sense and respond to change?
Reply:I'm just gonna quote the link above....





"Getting a definite answer if viruses are alive or not may never happen."
Reply:1. not made of cells


2. do not use energy


3. do not reproduce themselves
Reply:they need a host to reproduce (can t do it on their own)


they have no cell wall (only a capsid made of protein and in some cases part of the cells they infected)


they do not metabolize depending on the host for resources





other: they are not able to grow and do not respond to stimuli