The division shall have and exercise such of the powers and functions of the commission in the administration of the workers’ compensation law as the commission may by regulation prescribe; provided, however, that the power and duty to review any award made under the workers’ compensation law, as authorized by sections 287.470 and 287.480, may not be delegated, but such power and duty shall be exercised exclusively by the commission; and provided further, that the commission shall exercise no authority with respect to the selection or tenure of office of any individual appointed or employed by the division in the administration of the workers’ compensation law.