Which of the following is NOT a characteristic of pus?

The characteristic that distinguishes pus is its appearance and composition. Pus is a thick fluid that is typically opaque and often yellow or greenish due to the presence of dead white blood cells, cellular debris, and bacteria. It is formed as a response to infection or inflammation, where the body sends white blood cells to the site of infection.

The option stating that pus is typically clear in appearance is incorrect because pus is not clear; rather, it is marked by its color and viscosity, which indicates the presence of the aforementioned cellular components and inflammatory reaction. Additionally, the presence of white blood cells, a thicker consistency, and debris from dead cells are all characteristics that help define pus, differentiating it from other bodily fluids that may be clearer or less dense.