(a) If at any time any member of the Board is for any reason unable to exercise the functions of his or her office, the Governor General may after consultation with the appropriate body appoint a person who is qualified to be appointed as a member of the Board to act as a member, and any person so appointed shall, subject to the provisions of subsection (3), continue to act until the office in which he or she is acting has been filled or, as the case may be, until the holder thereof has resumed his or her functions or until his or her appointment to act has been revoked by the Governor General.