VIRUS

Virus
          - particles smaller than cells
          - noncellular
          - specific
          - DNA or RNA
Martinus Beijerinck
         - first to use the term virus


STRUCTURE
     - capsid- protein surrounding the DNA or RNA
     - bacteriophages - virus infecting bacteria

DNA viruses
          - hepa B, smallpox, cowpox, herpes
RNA viruses
          - AIDS, mumps, common colds, leukemia, measles