NOCTI Biomed Practice Exam 2025 - Free NOCTI Biomed Practice Questions and Study Guide

Viruses require host cells for reproduction because they are obligate intracellular parasites. This means that they cannot reproduce or carry out metabolic processes independently; they need to infect a living host cell to replicate. Once inside a host cell, viruses hijack the cell's machinery, such as its ribosomes and enzymes, to produce copies of themselves.

The host cell provides essential components and an environment for the virus to multiply, which is why it is critical for the virus's life cycle. Without a suitable host cell, a virus cannot reproduce or propagate its genetic material. Other options, while related to biological processes, do not fully encompass the specific need of viruses for host cells during their reproduction process. For instance, while living organisms can provide host cells, not all living organisms are suitable for all viruses. Similarly, viruses do not reproduce with the assistance of other viruses or purely in an environment without host cells.