Which term describes a rod-shaped bacterium?

The term that describes a rod-shaped bacterium is bacillus. Bacteria are classified by their shapes, and bacilli specifically refer to those that are elongated, resembling a rod. This shape can influence how the bacteria behave, their arrangement, and their overall function within their environment.

Coccus refers to spherical-shaped bacteria, while vibrio describes a curved or comma-shaped bacterium. Spirillum is used for bacteria that are spiral or corkscrew-shaped. Understanding these terms is essential for microbiological identification and classification, as the shape can provide insights into the bacteria's characteristics and potential behavior in different environments.