Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
A ball is a spherical or ovoid structure that can refer to various anatomical or pathological formations, including bacterial colonies. In microbiology, 'ball' often describes the shape and aggregation of cells.
5 Must Know Facts For Your Next Test
Certain bacteria form spherical clusters known as cocci, which can be visualized as balls under a microscope.
Bacterial meningitis often involves round bacterial cells like Neisseria meningitidis, which appears in pairs resembling balls.
Staphylococcus aureus forms grape-like clusters of spherical cells called staphylococci.
Encapsulated bacteria such as Streptococcus pneumoniae have a polysaccharide capsule giving them a smooth ball-like appearance under staining.
Microscopic examination of cerebrospinal fluid (CSF) in suspected meningitis cases often reveals ball-shaped bacterial cells.