Wisconsin Barber Practice Exam

The service that is known to alter the chemical structure of the hair is the process of creating permanent waves. This service involves using chemical solutions to break and reform the disulfide bonds in the hair, which changes its structure and allows for the creation of curls or waves that last for an extended period of time. The chemicals used in this process penetrate the hair shaft, affecting its internal composition and resulting in a permanent change to the hair's texture.

In contrast, haircutting primarily involves trimming hair without affecting its internal structure. Coloring, while it alters the appearance of the hair by changing its color, does not fundamentally change the hair's chemical bonds. Conditioning treatments are designed to improve the hair's condition and manageability but do not change its chemical structure either. Therefore, the most accurate choice that involves a significant change to the hair’s chemical makeup is the service that creates permanent waves.