Michigan Cosmetology Licensing Practice Exam

Sebaceous glands are found all over the skin, except for the palms and soles of the feet. These glands produce an oily substance called sebum, which helps to lubricate and protect the skin. This is the primary function of the sebaceous glands, making option C the correct answer. Option A is incorrect because melanin is actually produced by melanocytes, not sebaceous glands. Option B is also incorrect because sweat is produced by eccrine glands, not sebaceous glands. Option D is incorrect because keratin is produced by cells in the epidermis, not sebaceous glands. Therefore, the primary function of the sebaceous glands is to produce sebum, protecting and moisturizing the skin.