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The simple answer to this question is "no", but as usual in medicine, there are no simple answers.
First, we must understand that viruses are not "alive" in any traditional sense. They are basically little packages of DNA or RNA (the instruction codes for life) that require a host cell to be able to begin behaving in a life-like way (producing proteins and exerting influence on the world around them). So in this sense, a virus most definitely needs a host to truly live.
Perhaps a better question (or at least a different one) might be "does a virus necessarily need a host to survive"? The answer to this question is a fairly definite "no". Some viruses outside the body can survive for hours, even days, on inanimate objects, waiting for another host to pick them up and become infected with them. This is the case with Rhinovirus, a common cause of the common cold.
On the other hand, some viruses (like HIV) can survive only a very short time outside their human hosts - sometimes only seconds or minutes.
So in conclusion, a virus definitely requires a host to carry out its life mission of reproducing itself and producing disease, but does not require a host (necessarily) to survive.
Wiki User
∙ 15y ago
Wiki User
∙ 13y agoThe DNA must be reproduced to make more infected cells so yes they must have a host in order to become a full-on virus.
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What infectious agent live only by invading cells?
strict pathogens like Spirochetes only can live in host due there short genome
Microbiology If there were no plaques on your plate offer an explanation?
Because viruses cannot multiply without a host cell, they cannot be grown in sterile media the way bacteria can. Host cells must be provided for the virus to infect. Bacteriophage may be cultured with bacterial cells in liquid culture or on plates. To culture on plates, bacteria and bacteriophage are combined in melted agar and then poured into plates. The bacterial cells divide and evenly cover the surface of the plate forming a lawn. Wherever bacterial cells have been destroyed by the bacteriophage, clearings called plaques will appear in the lawn. Because it is harder to culture animal cells than it is for most bacteria, it is also more difficult to grow animal viruses in the lab. Some animal cells will grow in culture dishes much as bacteria do and will form a single layer on the bottom of a dish that contains a suitable growth medium. Viruses that can infect these cells can be grown along with them. Animal cells that are infected by the virus will display visible deterioration. Some viruses whose host cells can not be grown in culture can be grown in living animals such as rabbits, mice, and guinea pigs. Other viruses can be grown in fertilized chicken eggs. However, because some viral host ranges are highly specific, each virus infects only certain cell types, I cannot grow all cells in culture, yes grow all viruses.
What type of microorganism can only grow and reproduce in host cells?
Viruses.(although they aren't completely clarified as living beings)
Viruses do not contradict the idea that all living things are made of cells because?
Viruses aren't considered to be alive because they depend on a host cell for energy and reproduction.
How are viruses like organisms?
Well, if you consider a cell a living organism, then yes. A virus is a living organism because, like cells, they usually regulate in your body. On a certain basis, viruses can be extremely harmful, causing sickness among its host. Otherwise, viruses are injected inside a host(viruses are already dead) to help prevent illness and create an immunity.
Why can bacteria be grown in a petri-dish but not possible for viruses?
Viruses need host cells to replicate and this cannot be done by growing them like bacteria cells are grown.
Is there a difference with viruses and cells?
Yes there is a difference. Viruses are non-living and cells are living This is because Viruses can't reproduce on their own without a host. They don't have a metabolism like cells. They can't maintain homeostasis. They cannot synthesize proteins (they lack the ribosomes to do so) without a host. Without a host viruses can neither generate nor store ATP (adenosine triphosphate). Viruses cannot live unless they have a host.
Do both cells and viruses have genetic material?
Viruses do not contain DNA or RNA . . . they 'steal' those molecules from their host living cell.
What infectious agent live only by invading cells?
strict pathogens like Spirochetes only can live in host due there short genome
How viruses use the cells of living organisms to reproduce. What is the type of cell used by the virus called?
host
Why are viruses called obligate parasite?
Because they absolutely require living host cells in order to multiply
ARE Viruses are a type of cell?
The type of cells that viruses live in are host cells. Viruses need host cells in order to reproduce or multiply.
Does a virus use sexual reproduction?
Viruses cannot reproduce themselves alone. They inject their DNA into living cells of a host organism. The virus cells use the host cells to develop themselves and leave the cell when ready. Viruses are not living, so they are dependent on a living organism for reproduction.
What could you use to grow a virus on?
Due to their nature obligate intracellular parasites viruses cannot be grown in standard culture media, they must be grown on living cells or in multi- celled organisms. Various methods by which host cells may be maintained to support virus growth include- 1) Solid mediums - plaque assay-mixing cells and virus using pour plate or soft agar overlay method. 2) Growth in liquid culture- by mixing together host and viral cells 3) Growth in tissue culture - cells from plants or animals may be grown 'in vitro' often in flasks on a plastic substrate 4) grown in host organism -viruses which normally infect plants or animals or bacteria can be grown simply by infecting the living host 5) Embryonated eggs - fertilized and growing eggs usually from chickens make an excellent cheap 'in situ' growth chambers
What cells do the cell theory apply to?
plants and animalsmulticellular organisms fungi
Which is the difference between bacteria and viruses that shows the bacteria are living organisms and viruses are not?
Only Bacteria can reproduce outside of a host.. Bacteria are made of cells
What difference between bacteria and viruses shows that bacteria are living organisms and viruses?
Bacteria are able to reproduce on their own while viruses need a host to.
