Why can't a virus replicate itself without a host?

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  • 2 months ago
    Favourite answer

    because it is not even a cell, it is literally a small jumble of dna in a capsule. A bacteria can grow outside a cell because it is much bigger, and has all the features of a living cell, a virus is tiny and does not have a fraction of the life giving features a bacteria does. A virus is basically dead until it enters a living cell. It is only when it is in there does it multiply, because the environment is optimal for multiplication to happen. A virus cannot replicate by itself because it doesn't have a cell membrane nor does it metabolise food on its own or anything. It needs assistance from an actual living cell, with all the features that can give rise to multiplication. 

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  • Snoopy
    Lv 6
    2 months ago

    Because it would die without organic material as living matter is only organic on earth. 

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  • MARK
    Lv 7
    2 months ago

    Because a virus is either DNA or RNA. That is all it is. In order to replicated viruses both DNA and RNA are required and all the biochemistry for synthesising more virus.

    If you want it in very simplistic terms a virus is nothing more than a blueprint. It requires an engineering firm to turn the design into the finished product. The cell is the engineering firm.

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  • 2 months ago

    Because, by definition, all viruses lack a metabolism.  They depend upon their host to supply the metabolism while they supply only the genetic instructions that direct the host's metabolism.

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  • 2 months ago

    Let's suppose I go and look at all the chemical bits and pieces in my living room. I might find complex molecules from the tiny drops of wine that ended up on my coffee table when I set a glass there. Or bits of fibres from my clothes and socks. There would be dead skin cells making up bits of dust and dead and living bacteria. The point is, there is all manner of detritus and chemical leftovers.

    A virus is basically strands of DNA or RNA wrapped up in a protein shell. In many respects it is nothing more than bits and pieces left over ... a sort of chemical waste due to living organisms.

    When viruses come into contact with cells they shove their DNA or RNA into that cell. They don't do this to survive or to reproduce. They do this because they happen to have chemical structures that result in that interaction. Cells see this DNA or RNA and just respond to it.

    Over millions of years, what started out as chemical leftovers became the viruses we see today by evolution. The instructions they carry are instructions to make them. Their structures allow them to get that genetic material into cells. In other words, given the sheer amount of chemical crud leftover from living cells and enough time, we now have viruses that infect cells and use the cellular machinery to reproduce them.

    This might sound like a strange answer to your question but what I'm trying to get across is the idea that viruses are just chemical bits and pieces that managed to replicate using cell hosts because evolution weeded out the structures that couldn't! 

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  • 2 months ago

    Because it lacks reproductive organs. It injects its own genetic material into cells and hijacks their systems.

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  • 2 months ago

    because it can't create the same living conditions on its own. It is completely dependent on hosts ie humans. Humans are so inviting. and .generous.

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  • 2 months ago

    Because it doesn't have any of the usual machinery the cell has to do that. It's just a strip of genes with a coating.

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  • mokrie
    Lv 7
    2 months ago

    Not a doctor but I would imagine that just like people they need food to survive and they probably get that from entering our blood stream. Then they can replicate.

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    • Ted K
      Lv 7
      2 months agoReport

      Jeez, food?  It's 2020, fer chrissake.  How can someone be THAT ignorant about what a virus is???  So easy to just look it up.

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