There seems to be a lot of confusion on another thread as to exactly what a virus is! Not surprising, considering that SCIENTISTS can't even seem to agree exactly what it is.

The big question is- Is a virus alive? That is a debate- And in reality it comes down to semantics- You have to decide exactly what your meaning of 'alive' is.

By the 'traditional' way of defining life, a virus is NOT alive- They do not move (on their own), they do not respire, do not respond to a change in environment. In addition, they cannot reproduce without the aid of a host cell.

Viruses do NOT produce their own proteins to grow and/or reproduce. So, They really aren't alive. I think some of the confusion comes from people saying that they can be 'killed'- again, this is semantics- They aren't really killed, but destroyed (and some with MUCH difficulty!)

They can, and do- evolve, however. When they find a host and reproduce, the genetic code can change, which is how they become worse and more resistant to treatments, etc. Viruses are usually specific as to what makes a suitable host- often they are unable to go between species, but sometimes in evolving they become able to do so.

It is important that the distinction between a bacteria and a virus be understood, because a lot of people will assume that if something is cleaned and sanitized it must be disease free. This simply isn't the case- a lot of viruses can withstand chemicals and heat that would destroy the item that you are attempting to sanitize...

Also, they are SMALL- They are measured in terms of NANOMETERS- Which is 1,000,000,000th of a meter.... THOUSANDS can fit on the period at the end of this sentence. (<-----That one) The can hide out pretty easily!

Hope this helps, rather than confusing more

-Andrew

Great info!

good info , this was what i was trying to explain and not succeeding

Andrew, you just explained that better in a matter of minutes than my A&P professor did in an entire class period! Thank you!