Ball

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

1. Certain bacteria form spherical clusters known as cocci, which can be visualized as balls under a microscope.
2. Bacterial meningitis often involves round bacterial cells like Neisseria meningitidis, which appears in pairs resembling balls.
3. Staphylococcus aureus forms grape-like clusters of spherical cells called staphylococci.
4. Encapsulated bacteria such as Streptococcus pneumoniae have a polysaccharide capsule giving them a smooth ball-like appearance under staining.
5. Microscopic examination of cerebrospinal fluid (CSF) in suspected meningitis cases often reveals ball-shaped bacterial cells.

Review Questions

• What type of bacterial cell arrangement resembles a cluster of grapes?
• Which encapsulated bacterium appears smooth and ball-like under staining?
• How does Neisseria meningitidis typically appear when viewed through a microscope?

Related terms

Coccus: A spherical bacterium.

Meningitis: Inflammation of the protective membranes covering the brain and spinal cord.

Capsule: A polysaccharide layer outside the cell wall of some bacteria providing protection and contributing to pathogenicity.