Which hair structure is often characterized by a whorl pattern?

The hair follicle is the correct choice as it is the structure responsible for producing hair and is characterized by various patterns, including whorl patterns. A whorl pattern in hair growth occurs when the hair follicles are oriented in a circular or spiral formation on the scalp, often found at the crown of the head. This unique characteristic can affect hair styling and cutting, as well as the overall appearance of the hair. The hair follicle plays a significant role in how hair grows and can determine different growth patterns. Understanding the structure of the hair follicle is important for cosmetologists in providing hair care and styling services.