Rock the New Jersey Cosmetology State Exam 2025 – Style Your Way to Success!

The stratum corneum is the outermost layer of the epidermis and is specifically known for containing keratin, a protein that provides waterproofing and protection to the skin. This layer consists of dead skin cells that are filled with keratin, making it crucial for maintaining the skin's barrier function against environmental damage and preventing water loss. The presence of keratin in the stratum corneum helps in the overall structure and resilience of the skin, making it an essential component in skincare and cosmetology.

While the epidermis generally includes various layers where keratin is produced, it is the stratum corneum that is predominantly recognized for its concentration of this vital protein. Other layers, such as the stratum lucidum, also contain keratin, but only in specific contexts and not to the extent found in the stratum corneum. Therefore, identifying the stratum corneum as the correct answer highlights its specialized role within the overall structure of the skin.