Section 61 of the constitution states that "The executive power of the Commonwealth is vested in the Queen and is exercisable by the Governor‑General as the Queen's representative, and extends to the execution and maintenance of this Constitution, and of the laws of the Commonwealth." Section 2 provides that a governor-general shall represent the Queen in Australia. The governor-general is appointed by the monarch on the advice of the prime minister of Australia. In practice, the governor-general carries out all the functions usually performed by a head of state, without reference to the Queen; though the governor-general is the Queen's representative, he or she is not the monarch's delegate or agent. Under the conventions of the Westminster system, the governor-general's powers are almost always exercised on the advice of the prime minister or other ministers of the Crown. The governor-general may use the reserve powers of the Crown as prescribed by the constitution, though these are rarely exercised. One notable example of their use was by Governor-General Sir John Kerr during the Australian constitutional crisis of 1975.