👉 In biology, "capsidae" refers to a group of organisms that have a spherical or cylindrical shape. These organisms are typically found in the eukaryotic kingdom and include viruses, bacteria, fungi, and protozoa. The term "capsidae" is derived from the Greek words "capos" (which means "spherical") and "diaspora" (meaning "cylinder"), which both describe the shape of a capsid. Capsids are structures that some