what do you know about virus - Biology Blog
Virus Viruses are simple noncellular entities consisting of one or more molecules of either DNA or RNA enclosed in a coat of protein. They become active only in living cells and they are intracellular parasites. The size of the virus is 0.02 to 0.03 micrometer but the size of the virus in smallpox is 200nm in diameter which is the largest size of the virus. A fully assembled infectious virus is called a virion . " The main function of the virion is to deliver its genetic material into the host cells so that the genome can be expressed by the host cell. " Viral Structure - The structure of virions is very diverse, varying widely in size, shape, and chemical composition. All viruses have a nucleocapsid composed of nucleic acid surrounded by a protein capsid. The capsid is formed as single or doub...