Eli5: what exactly is a virus and are viruses alive?
In: 130
A “cell” is like a factory. It has machines that it uses to do normal cell things, and instructions to run those machines. A cell uses those machines and instructions to live, grow, and eventually copy itself, which is called “reproduction.”
On the other hand, a “virus” is just a set of instructions. It has no machines, so it needs to find a cell, a “host,” to put its instructions into. When it does, its instructions take control of the host’s machines. Instead of helping the cell live, the virus’s instructions make the machines create copies of the virus. Eventually, the cell will be so full of virus copies that it bursts open, setting those new viruses free to find new cells to repeat that process.
Are viruses alive? That’s still an ongoing debate. There is no one universally-accepted definition of what can be considered “alive.” Some say that something alive should be able to grow, copy itself, and evolve on its own. Under that definition, a virus is *not* alive – it can’t do those things itself, it needs a host cell. And yet, it has the instructions on how to copy itself, and can do that inside the host…
The short answer is, we don’t know if viruses are alive! They are an edge case where none of our standards completely fit. At least, not *yet.*
Latest Answers