The intention of the Legislature is hereby declared to be that the executive officer shall perform and discharge under the direction and control of the board the powers, duties, purposes, functions, and jurisdiction vested in the board and delegated to him by it.
Any power, duty, purpose, function, or jurisdiction which the board may lawfully delegate shall be conclusively presumed to have been delegated to the executive officer unless it is shown that the board by affirmative vote recorded in its minutes specifically has reserved the same for its own action. The executive officer may redelegate to his subordinates or to an appointing power he designates, unless by board rule or express provision of law he is specifically required to act personally.