acellular

Acellular means “not made of cells.”

• Most living things are built from cells (one cell or many cells), but viruses are different because they have no cells at all.
• An acellular virus is usually just genetic material (DNA or RNA) wrapped in a protein coat (and sometimes an outer covering).
• Because it has no cells, a virus cannot do life processes on its own (like making proteins or producing energy). It must enter a host cell and use the host’s machinery to make more viruses.
• Think of a virus like a USB drive: it carries information, but it can’t “run” by itself—only when plugged into a computer (the host cell) can it make copies.
• So, “acellular” helps explain why viruses are often described as being on the borderline between living and non-living: they act “alive” only inside a host cell.