Microbiology
Virus
A microscopic infectious agent that can only replicate inside living cells. Viruses consist of genetic material (DNA or RNA) surrounded by a protein coat, lacking the machinery for independent metabolism.
Biological Context
Viruses aren't considered fully alive—they're obligate parasites of cellular life. They evolve rapidly due to high mutation rates. Viruses drive evolution by transferring genes between organisms and by selecting for immune defenses.
Business Application
Viral business models hijack host systems to replicate—viral marketing uses social networks, viral products spread through user sharing. Like biological viruses, viral business strategies depend on host infrastructure they don't own or control.