What distinguishes cells from viruses?

The distinction between cells and viruses is fundamentally rooted in the characteristics of life. Cells are considered living organisms because they possess the ability to grow and develop, which encompasses the processes of cell division, metabolism, and responding to changes in their environment. Cells undergo various stages of differentiation and can increase in size and mass, adapting their functions accordingly.

On the other hand, viruses do not exhibit these characteristics. They cannot grow, develop, or increase in size independently. Instead, viruses must infect a host cell to replicate and proliferate, relying entirely on the cellular machinery of their host for reproduction. This critical difference sets cells apart as autonomous units of life, while viruses remain acellular and dependent on other living organisms to carry out their lifecycle.

Although it is true that cells can replicate independently, obtain and use energy, and respond to their environment, the aspect of growth and development as a defining characteristic of living organisms underscores the distinction more clearly. Thus, the ability of cells to grow and develop is a primary feature that differentiates them from viruses.