Capsomeres are the individual protein subunits that make up the capsid, the protective outer shell of a virus. These subunits are arranged in specific geometric patterns that determine the overall shape of the virus:

Helical: The capsomeres are arranged in a spiral or ribbon-like manner around a central axis (e.g., Tobacco Mosaic Virus).

Polyhedral: The capsomeres form a many-sided shell, most commonly in the form of an icosahedron (a 20-sided polygon with 12 vertices) (e.g., Adenovirus).

──────────────────────────────────────────────────────────────────────────────────────────