Which type of bacteria rarely shows any active motility?

Which type of bacteria rarely shows any active motility?

• A. Bacilli
• B. Spirilla
• C. Cocci
• D. Vibrios

Answer: (C)

Cocci are a type of bacteria characterized by their spherical shape. Unlike bacilli (rod-shaped), spirilla (spiral-shaped), and vibrios (comma-shaped), cocci typically do not exhibit motility or movement. They usually remain in fixed positions, forming clusters or chains depending on their arrangement during cell division. This lack of motility is due to their simpler structure; cocci do not possess flagella, which are the whip-like structures that many motile bacteria use to propel themselves through their environment. The other shapes of bacteria can exhibit movement through various mechanisms. For instance, bacilli may utilize flagella for motility, while spirilla are known for their corkscrew motion, allowing them to move through viscous environments. Vibrios can also move due to their single polar flagellum, enabling a more mobile lifestyle in aquatic environments. Thus, the distinct structural aspects of cocci lend to their classification as non-motile bacteria.

Cocci are a type of bacteria characterized by their spherical shape. Unlike bacilli (rod-shaped), spirilla (spiral-shaped), and vibrios (comma-shaped), cocci typically do not exhibit motility or movement. They usually remain in fixed positions, forming clusters or chains depending on their arrangement during cell division. This lack of motility is due to their simpler structure; cocci do not possess flagella, which are the whip-like structures that many motile bacteria use to propel themselves through their environment.

The other shapes of bacteria can exhibit movement through various mechanisms. For instance, bacilli may utilize flagella for motility, while spirilla are known for their corkscrew motion, allowing them to move through viscous environments. Vibrios can also move due to their single polar flagellum, enabling a more mobile lifestyle in aquatic environments. Thus, the distinct structural aspects of cocci lend to their classification as non-motile bacteria.