virus's

[Mr Joe]

ive read over and over how virus's arent considered living..........why?

[destiny]

viruses (n.) Any of various simple submicroscopic parasites of plants, animals, and bacteria that often cause disease and that consist essentially of a core of RNA or DNA surrounded by a protein coat. Unable to replicate without a host cell, viruses are typically not considered living organisms.

--- American Heritage Dictionary of the English Language – Fourth Edition


It depends on what you mean by the word 'living'.

Check out http://www.cs.unc.edu/Research/nano/ed/virus.html

[monny]

Viruses are not considered living bcoz they cannot live independently.Yes,they can multiply and replicate but thats only when they r inside host cell.Outside, they r as good as simple chemical substances.

[Poison]

Search please. You will find what you want.

[Darby]

They break several of the "Life Rules," and you have to decide how important the rules are to you. I'd say more than 50% of biologists, when pushed, would consider them alive. I have no actual data to support that claim.

But -

- They're not truly cellular, even if they have membrane coating swiped from the host cell.

- Outside of the host cell, they have no real metabolism.

- Once formed, they neither grow nor develop.



The reproduction thing doesn't hold up - there are limitations to many parasites that no one would consider not alive that pretty much match a virus.

[sachin]

Viruses are just complex molecules........ That serves as vectors......

But my question is....

Why were Viruses had Evolved?

[jimmystang]

hmm... but viruses do evolve

[jimmystang]

oops, i guess sachin had asked the same question

[sachin]

oops, i guess sachin had asked the same question

I want to ask......

Why they come into existance.??.........

I m asking "Why" not "How" (since I know how )

[MrMistery]

there is no why.
why does a bacteria survive? does it want to? no. it just does. why(in this case) is not something a biologist can answer. a creationist might have an answer for you, but i doubt it would satisfy you..

[Mr Joe]

how bout this. ill play devils advocate a little
how is a virus non living if it has DNA ?
this is what leads me to beleive there living, because as we all know DNA is the blueprint of LIFE.
one last thing, i know alot of people say its because they cant reproduce with out a host, making them non living
i cant reproduce by myself, being a male i need a female to assist in the process?
just food for thought.

[MrMistery]

You're not living :p
On a more serious note, having genetic material is a necessary but not sufficient condition for something to be living.
You can't reproduce as an individual, but the species can

This whole living/non-living/in between thing is purely definition. It really doesn't matter. Viruses are what they are regardless if we consider them living or not...