1. Entry into host cells: The virus comes into contact with a suitable host. Pierces the host body. Through the pore, the virus genome enters the host cell. The virus increases the number in the host’s body.
2. Obligate endoparasites: Virus are obligate endoparasites. It resides in living host cells. Virus cannot multiply without a living host. Cannot multiply even in culture medium.
3. Coercing living cells to obey instructions: Virus contain nucleic acid inside the capsid. Virus contain either DNA or RNA as nucleic acid. The nucleic acid of the virus combines with the nucleic acid of the host. Then it creates new virus under the instructions of the virus. Dr. Siddiq Publications
4. Host Specificity: Virus are host specific. Bacteriophages attack bacteria, cyanophages attack cyanobacteria, plant virus attack plants and animal virus attack animals. However, if the virus changes its host, it is called an emerging virus.
5. Attack Site Specificity: Virus are host specific and attack site specific. Hepatitis B and C virus attack liver cells, HIV white blood cells, poliovirus the spinal cord, papillomavirus the genitalia, herpes simplex virus the skin, Epstein Barr virus the nose and pharynx, and T-lymphotrophic virus the white blood cells.
6. Genetic modification: Genetic modification can occur in virus. Mutant virus are a serious threat to the ecosystem. Vaccines or drugs are not effective against the mutated generation. Virus such as flu virus and covid-19. For this reason, every year new antibiotics have to be taken.