The virus literally means a poison molecule that cannot be separated from a bacterial filter because it is smaller than a bacterium and its chemical structure is a piece of nucleic acid surrounded by a protein envelope.
Ivanovsky, a Dutch scientist, is credited with the discovery of the virus because he discovered the virus in tobacco-affected husbands with Mosaic disease.
Bacteriophages were discovered by scientists Wart and D. Herle
Size – The size of a normal virus is 10–200 nm but the size of the largest virus is up to 300 um and there is an element of the virus that animal viruses are smaller in size than plant viruses. The size of the virus is dense and complex.
Chemical Organization –
The basic structure of all types of viruses is the same. All viruses have either one of the genetic material RNA or DNA, but they are covered by protein cover and all viruses have only one molecule of genetic material. The number of pairs of nucleotides in them varies from 1000 to 250000 but their number is not fixed.
Classification of viruses
Scientists andrelowff, horne and tournier classified viruses, so their classification is also called LHT classification and it was recognized in 1966 by the International Committee on Nomenclature of virus naming of viruses.