Final answer:
Treponema pallidum is a spirochete bacterium with a thin, spiral, corkscrew-like shape. This distinctive shape aids in its identification and is crucial for the diagnosis of syphilis.
Step-by-step explanation:
Treponema pallidum, the bacterium that causes syphilis, has a distinctive shape. It is a spirochete, which means it has a thin, spiral, corkscrew-like shape that allows it to move in a twisting motion. This shape is characteristic of several bacteria in the spirochete family. Understanding the shape of T. pallidum is important because it can help in the identification of the bacteria when viewing it under a microscope, which is critical for diagnosing syphilis