A virus can be considered living as it:

Question

Accepted Answer

The correct option is 3:

Viruses exist in a fascinating grey area between living and non-living entities. The most crucial characteristic that allows us to consider a virus "living" is its ability to reproduce. However, viruses cannot reproduce on their own; they are obligate intracellular parasites, meaning they must infect a host cell and hijack the host's cellular machinery to replicate their genetic material and produce new viral particles. This act of replication, even though it requires a host, is a fundamental process associated with life. Once inside a suitable host cell, a virus can direct the synthesis of its components and assemble new virions, effectively passing on its genetic information, which is a hallmark of living organisms. Without a host cell, a virus is essentially an inert package of genetic material and protein.

The incorrect option is 1: Respire

Viruses do not respire. Respiration is a metabolic process that generates energy, typically involving the breakdown of organic molecules. Viruses lack the cellular machinery (like mitochondria) to carry out respiration and rely entirely on the host cell for energy.

The incorrect option is 2: Respond to touch

While some living organisms respond to touch, this is not a universal characteristic of life, and viruses do not exhibit this property. Their interactions are primarily chemical, involving binding to specific host cell receptors, rather than a physical response to touch.

The incorrect option is 4: Can cause disease

Many non-living things, such as toxins or environmental factors, can also cause disease. The ability to cause disease is a consequence of viral activity within a host, but it is not a defining characteristic that classifies a virus as living. For example, a poison can cause disease, but it is not a living organism.