What characteristic is typical of bacilli bacteria?

Bacilli bacteria are characterized by their rod-shaped structure. This distinctive shape plays a significant role in the identification and classification of bacteria in microbiology. The rod-like form allows for certain physiological and structural features that are typical of this type of bacteria, such as specific patterns of growth and reproduction. Because bacilli are elongated compared to spherical (cocci) or spiral (spirilla) bacteria, their morphology can influence how they interact with their environment, including their movement and the formation of colonies.

The other options describe different shapes or structures that do not pertain to bacilli. Spherical bacteria would be classified as cocci, while spiral bacteria fall under spirilla or spirochetes. Flagellation, which relates to the presence of flagella that aid in movement, is not a defining characteristic of all bacilli, though some may possess flagella. Understanding these fundamental differences is crucial for identifying bacterial types and understanding their behaviors in different contexts.