The examination of applicants for license to practice under this chapter must be conducted under rules adopted by the board and must include both practical demonstrations and written or oral tests in reference to the practices for which a license is desired and in reference to related studies or subjects as the board may determine necessary for the proper and efficient performance of a practice. The board may require the practical portion of the examination be conducted by schools of cosmetology as part of graduation requirements. The examination may not be confined to any specific system or method and must be consistent with the practical and theoretical requirements of cosmetology.