Papua New Guinea is a parliamentary democracy governed under the constitution of 1975 as amended. The monarch of Great Britain and Northern Ireland is the head of state and is represented by the governor-general. The government is headed by the prime minister, who is appointed by the governor-general. The unicameral National Parliament consists of 109 members who are popularly elected for five-year terms. Administratively, the country is divided into 20 provinces, the autonomous region of Bougainville, and the National Capital District.