Coccus

A coccus (plural cocci) is any bacterium or archaeon that has a spherical, ovoid, or generally round shape. It is one of the three distinct bacterial shapes, the other two being bacillus (rod-shaped) and spiral-shaped cells. A coccus (plural cocci) is any bacterium or archaeon that has a spherical, ovoid, or generally round shape. It is one of the three distinct bacterial shapes, the other two being bacillus (rod-shaped) and spiral-shaped cells. Cocci is an English loanword of a modern or neo-Latin noun, which in turn stems from the Greek masculine noun cóccos (κόκκος) meaning 'berry'. Cocci may occur as single cells or remain attached following cell division. Those that remain attached can be classified based on cellular arrangement: