What is the difference between bacteria and a virus?
Bacteria are much larger than viruses and much more complex. In fact the biggest virus is only as large as the smallest bacterium. A typical bacterium has a rigid cell wall containing a cell membrane, which holds cytoplasm (water like substance that fills the cell). Within that fluid are chromosomes that hold instructions for making new bacteria and performing a host of other functions. Viruses are much smaller than bacteria and are measured in millions of a millimeter. Viruses are much simpler than bacteria and are made up of only nucleic acid, a protein coat, and a spiked envelope. Viruses are unable to live in the absence of a living host cell.
