EVERYDAY SCIENCE

Detailed explanation-1: -Introduction. Viruses are obligate intracellular parasites and their reproduction entirely relies on the host cell machinery for the synthesis of viral components such as nucleic acids, proteins and membranes.

Detailed explanation-2: -Since viruses are intracellular parasites, they rely on their host cells for the energy, macromolecular synthesis machinery and the work benches for genome replication and particle assembly. Because of this dependence, viruses have evolved a myriad of mechanisms for exploiting normal host cell functions.

Detailed explanation-3: -A virus cannot replicate alone; instead, it must infect cells and use components of the host cell to make copies of itself. Often, a virus ends up killing the host cell in the process, causing damage to the host organism. Well-known examples of viruses causing human disease include AIDS, COVID-19, measles and smallpox.

Detailed explanation-4: -A lysogenic virus remains inactive for a period of time. In the lysogenic cycle, the viral DNA gets integrated with the host’s DNA and gets copied when the host cell replicates.

Detailed explanation-5: -A virus needs a living cell in order to reproduce. The living cell in which the virus reproduces is called a host cell.