It has to fit the shape of the cell that it is infecting.
It is actually the other way around. A virus destroys a host cell after it has make the replicants of the virus. The cell will split open (lyse) when full of new virions which then get released to infect other cells. Our immune systems can "destroy" a virus in a cell, but the cell itself does not do that. The immune system makes antibodies that fit the virus perfectly to block the way it would have attached to the cell to infect it. The antibody attaches to the virus to prevent its ability to attach to a cell. See the related question below about the lytic cycle for more details about virus "reproduction".
It is actually the other way around. A virus destroys a host cell after it has make the replicants of the virus. The cell will split open (lyse) when full of new virions which then get released to infect other cells. Our immune systems can "destroy" a virus in a cell, but the cell itself does not do that. The immune system makes antibodies that fit the virus perfectly to block the way it would have attached to the cell to infect it. The antibody attaches to the virus to prevent its ability to attach to a cell. See the related question below about the lytic cycle for more details about virus "reproduction".
The protein capsid of the virus will only fit in a protein marker of a certain cell with that marker, which creates specificity to the cell they infect. For this reason, a virus that is harmful to a plant may be harmless to humans.
No where. A virus is not a cell.
A virus is many times smaller than either an amoeba or a bacteria. Perhaps thousands would fit into a bacterial cell.
What a cell and a virus have in common is the RNA or DNA. The virus can be either a RNA virus or a DNA virus.
The cell infected by a virus is referred to as the host cell. The virus hijacks the host cell's machinery to replicate and produce more virus particles.
A virus.
Both a living cell and a virus contain nucleic acid. The virus has a capsid, whereas a living cell does not.
The cell invaded by the virus is called a host cell because it provides the environment and resources necessary for the virus to replicate and multiply. The virus uses the host cell's machinery to produce more viruses, ultimately leading to the destruction of the host cell.
A virus will replicate within a host cell.