Many animal parasites and bacterial disease agents infect a fairlybroad range of hosts, but viruses are often very specific to one type of tissue in one or a few species because
a) a virus must be recognized and "taken in" by a host cell.
b) different host cells vary greatly in the DNA or RNA they will replicate.
c) it is believed that viruses may have evolved from nucleic acids from these host cells genomes
d) both A and B are correct
e) all of the above are correct

Question

Many animal parasites and bacterial disease agents infect a fairlybroad range of hosts, but viruses are often very specific to one type of tissue in one or a few species because
a) a virus must be recognized and "taken in" by a host cell.
b) different host cells vary greatly in the DNA or RNA they will replicate.
c) it is believed that viruses may have evolved from nucleic acids from these host cells genomes
d) both A and B are correct
e) all of the above are correct

geometry_hater · Answer

possibly C at least thats what i would go with

cathyangs · Answer

wel...I think A would be correct. Viruses can replicate using host cells... don't know about B. C seems likely too.

anonymous · Answer

I think a is the best answer - cells have receptors on their surface which get highjacked and allow viruses to enter the cell. So a particular virus will need a particular receptor for entry and that receptor might only be expressed on a subset of cells - say T cells of the immune system for example which get attacked by the HIV virus.