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My teacher mentioned a few things in class, but I want to know why a virus is considered living or non-living.

2007-02-19 07:42:54 · 17 answers · asked by crystalgoddess101 1 in Science & Mathematics Biology

i need a reason that sticks to the characteristics of life: a living organism:
are made of cells,
require energy/ metabolize,
grow,
reproduce,
respond to environmental stimuli,
maintain homeostatsis,
& evolve and adapt.

2007-02-19 08:16:25 · update #1

17 answers

this is a tough question, i'm a virologist and i consider viruses as living, but in most text books they are regarded as non-living. Living things are composed of cells viruses are not, also they don't have homeostasis, they rely on the host cell to provide for all that. But viruses do adapt they do replicate, so in that sense they are living, but for the most part for your purposes its not living.

2007-02-19 08:40:34 · answer #1 · answered by rizo_rocker 2 · 0 0

2

2016-08-21 22:01:08 · answer #2 · answered by ? 3 · 0 0

Most virologists consider viruses to be living. You should try talking to one Nosrett.

Here's why.

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 - agreed, 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. As a matter of fact, we can make viral proteins reproduce viral RNAs in vitro, outside of a host cell.

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 arbitrary 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.

Many bacteria and fungi are obligate parasites, meaning they can't live or reproduce outside of their host. Are they any less alive?

2007-02-21 04:56:06 · answer #3 · answered by floundering penguins 5 · 0 0

Viruses can replicate themselves only by infecting a host cell. They therefore cannot reproduce on their own. Most virologists consider them non-living, as they do not meet all the criteria of the generally accepted definition of life.

2007-02-19 08:00:49 · answer #4 · answered by Toothie 2 · 1 0

non-living. It really isn't feeding off of anything, it is using the host cell to reproduce some more of it's genetic material. A virus is only a piece of genetic material (DNA or RNA) wrapped in a protein coat. It can't eat, it can't convert food into energy, it doesn't have any mitochondria. It has no organelles. the virus can't do anything unless it has a host cell, floating out in the open, a virus is harmless.

2007-02-19 07:54:37 · answer #5 · answered by buttercup 3 · 0 1

Most virologists consider them non-living, as they do not meet all the criteria of the generally accepted definition of life. as they lack the means for self-reproduction outside a host cell, but unlike parasites, viruses are generally not considered to be true living organisms. A definitive answer is still elusive. Some organisms considered to be living exhibit characteristics of both living and non-living particles, as viruses do. For those who consider viruses living, viruses are an exception to the cell theory as viruses are not made up of cells.

2007-02-19 07:56:34 · answer #6 · answered by nosrettaptnilc 2 · 1 1

bothcoz:LIVING#they reproduce within cells of living organisms
NON-LIVING#they dont respire
#cant reproduce except when within cells
of a living organism
#can form crystals and survive in this form
for many years

2007-02-19 07:54:27 · answer #7 · answered by kandy 2 · 0 0

It is not a living thing. It is unable to reproduce on its own. It depends entirely on a bacteria or a cell to help produce more viruses.

2007-02-19 07:46:16 · answer #8 · answered by . 1 · 4 1

Nope. Non-living.
No metabolism. A virus does not take in small molecules from the environment, process them for energy, and synthesize its own macromolecules from them.

2007-02-19 09:24:53 · answer #9 · answered by Anonymous · 0 1

no, i dont think so, it cant reproduce on its own and it needs a cell to reproduce. you need asexual or sexual reproduction according to the 7 needs of life.A virus does none.

2007-02-19 08:13:33 · answer #10 · answered by AllisonAmber 2 · 1 0

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