Answer:
Viruses are considered neither living nor non-living because they lack essential characteristics that define living organisms. Here are a few reasons why viruses are not considered living:
1. Lack of cellular structure: Unlike living organisms, viruses lack cells, which are the basic structural and functional units of life. Viruses are made up of genetic material (DNA or RNA) enclosed in a protein coat called a capsid.
2. Inability to carry out metabolic processes: Viruses cannot carry out essential metabolic processes such as respiration, growth, or reproduction on their own. They lack the necessary cellular machinery, such as enzymes and organelles, to perform these functions.
3. Dependence on a host organism: Viruses require a host organism to replicate and carry out their life cycle. They cannot reproduce independently and rely on hijacking the cellular machinery of their host cells to reproduce and spread.
4. Lack of response to stimuli: Living organisms respond to stimuli from their environment, such as light or temperature changes. Viruses do not exhibit any response to external stimuli, as they lack the necessary sensory and regulatory mechanisms.
So why do viruses need a host organism?
Viruses need a host organism for several reasons:
1. Replication: Viruses lack the cellular machinery required for replication. They need to infect a host cell and use the host's resources and machinery to replicate their genetic material and produce new virus particles.
2. Protein synthesis: Viruses rely on the host cell's machinery to synthesize viral proteins necessary for their replication and assembly.
3. Protection: The host organism provides a protective environment for the virus, shielding it from external threats such as the immune system or harsh environmental conditions.
4. Transmission: By infecting a host organism, viruses can be transmitted to other individuals of the same species, allowing them to spread and continue their life cycle.