Viruses don't grow; instead, they replicate by hijacking host cells to produce new viral particles.
Unlike living organisms that grow by increasing in size or complexity through the utilization of energy and nutrients, viruses employ a different strategy. They lack the cellular machinery necessary for independent growth. Therefore, viruses rely entirely on a host cell to replicate.
Here's a breakdown of the process:
- Attachment: A virus attaches to a specific receptor on a host cell's surface.
- Entry: The virus enters the host cell. This can occur through various mechanisms, such as endocytosis or fusion with the cell membrane.
- Replication: Once inside, the virus releases its genetic material (DNA or RNA). This genetic material then directs the host cell's machinery (ribosomes, enzymes, etc.) to produce viral proteins and replicate the viral genome. The host cell essentially becomes a virus-producing factory.
- Assembly: The newly synthesized viral components (proteins and genetic material) are assembled into new virus particles, called virions. Each virion is fully formed.
- Release: The newly assembled virions are released from the host cell. This can occur through lysis (bursting) of the cell, or through budding, where the virus particles are enveloped in a portion of the host cell membrane. These newly released virions can then infect other cells, continuing the cycle.
Essentially, viruses manipulate host cells into building new viruses. This means that each individual virus particle, or virion, is created in its fully-formed state. It does not grow in size or complexity after it is assembled. A virus starts as a complete particle and does not undergo a growth phase like a bacterium or other organism.
In summary, viruses don't grow; they replicate within host cells to create more copies of themselves, which are already fully formed.
