Illinois Nail Technician Practice Exam 2025 – Complete Prep Guide

Bacilli and spirilla are types of bacteria that have distinct shapes and movement mechanisms. The correct answer indicates that these bacteria propel themselves by using flagella and cilia.

Flagella are long, whip-like structures that can rotate, allowing bacteria to swim through liquid environments. Since bacilli are rod-shaped and spirilla are spiral-shaped, both can utilize flagella to move in a directed manner, making it easier for them to navigate through fluids. Cilia are shorter, hair-like structures that can also aid in movement, but they are less common among bacilli and spirilla. However, some bacterial species might have a combination of these structures that help them move effectively.

The other options describe different mechanisms that do not apply to how bacilli and spirilla move. Pseudopodia are temporary projections of eukaryotic cells used for movement and are not found in bacteria. Muscle contractions are a characteristic of multicellular organisms and do not pertain to bacterial motion. Diffusion is a passive process of movement at the molecular level and does not reflect how these bacteria propel themselves through their environment.