Types of Viruses Viruses are categorised as:
i. Plant virus: Virus that infect plants.
e.g. Tobacco mosaic virus, Cauliflower mosaic virus, Potato virus.
ii. Animal virus: Virus that infect animals. e.g. Adenovirus, Retrovirus(HIV), Influenza virus, Polio virus.
iii. Bacteriophages: Virus that infect bacterial cells. e.g. T4 bacteriophage.