Which cytoskeletal element is a hollow tube that helps move materials around the cell?

• A. Microfilaments
• B. Centrioles
• C. Microtubules
• D. Intermediate filaments

Answer: (C)

Think of the cell’s transport network as hollow tracks that cargo can ride along. Microtubules are long, hollow tubes made of tubulin that form these checkpoints inside the cell. Motor proteins such as kinesin and dynein walk along microtubules carrying vesicles, organelles, and other materials to where they’re needed, which is why they’re described as tracks for movement. They’re also involved in organizing the spindle during cell division, but their defining feature here is providing intracellular highways.

In contrast, microfilaments are thin, flexible actin filaments involved in movement and shape changes, not hollow tubes for transport. Centrioles are cylindrical structures that help organize microtubules during division rather than serving as transport tracks themselves. Intermediate filaments provide structural support, not movement along tracks.