A single virus particle or unit.
Individual virus particles, varying (according to the type of virus) from 10 to 300 nm, only those over 200 nm being recognizable by light microscopy.
Virus particle, consisting of a protein coat called a capsid, and a nucleic acid core.
A complete, potentially virulent virus particle, consisting of an RNA (ribonucleic acid) or DNA (deoxyribonucleic acid) core with a protein layer. A virion is the infective form of a virus.
A complete virus particle; a emit of genetic material, the genome, surrounded by a protective protein coat, the capsid. Sometimes the capsid is surrounded by a lipid envelope.