Bibhudatta Panda presented on viruses at the Department of Botany seminar. A virus is an infectious microbe composed of nucleic acid surrounded by protein, lacking cellular structure. Viruses range from 20-200nm and can mutate, making them difficult to classify. They were first discovered in 1892 but named in 1898. Viruses contain genetic material but cannot reproduce outside a host cell, so they are not considered living. Viruses are classified by shape, host, and life cycle, and can have lytic or lysogenic life cycles. Examples include plant, animal, and bacteria infecting viruses. While viruses have some beneficial uses, they can also cause diseases and epidemics in plants, animals, and humans like SARS