Viruses have no definite cell structure .when we classify microorganisms on the basis of their cell structure they are of four types:
bacteria (cynobacteria, vibrio cholera, staphylococcus)
protozoa(paramoecium, amoeba, euglena)
fungi (moulds, yeast)
While not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent particles. These viral particles, also known as virions, consist of two or three parts: (i) the genetic material made from either DNA or RNA, long molecules that carry genetic information; (ii) a protein coat that surrounds and protects the genetic material; and in some cases (iii) an envelope of lipids that surrounds the protein coat when they are outside a cell. The shapes of these virus particles range from simple helical and icosahedral forms for some virus species to more complex structures for others. Most virus species have virions that are too small to be seen with an optical microscope. The average virion is about one one-hundredth the size of the average bacterium.
name of four viral diseases are:
common cold by rhino virus
mumps by rubula virus