PATHOLOGY

Detailed explanation-1: -Viruses reproduce only inside the cells of the host organism. It utilises its host cell’s machinery to make copies of themselves.

Detailed explanation-2: -A host cell is a cell that harbors foreign molecules, viruses, or microorganisms. It may also be a cell that has been introduced with DNA (or RNA), such as a bacterial cell acting as a host cell for the DNA isolated from a bacteriophage.

Detailed explanation-3: -Option (d) viruses. Viruses reproduce inside a living organism. They can develop only inside the cells of the host organisms (which may be an animal, plant or bacterium).