Viruses are intracellular pathogens that bind to specific receptor molecules on the surface of the target cells for their entry to initiate infection. They exist as lifeless independent particles prior to their invasion of host cells which were subsequently infected due to virus. These parasitic particles find significant importance in the field of genetics, molecular and cell biology as they paved way for major advancement in human health aspects. In numerous researches and discussions were underway on these entities as of whether they belong to the realm of living organisms or not. | Virus The biological brain twister