Which is a characteristic of a virus, but not a bacterium?
a) capsid
b) causes illness
c) damages the cells in a body
d) transmitted in food and drink

The best answer to the question above is letter C, damages the cells in a body. 
A virus is a  tiny organism which may lead to mild to severe illnesses in humans, animals and plants which includes flu or a cold to something more life threatening like HIV/AIDS.

Viruses cannot grow or multiply on their own. They are not alive, thus, they need to enter a human or animal cell and take over the cell to help them multiply. They can also infect bacterial cells.

In my own word cell technology can  lead to advances in the understanding of diseases mechanism and transmission because diseases is very bad