The executive branch is composed of the president, a vice president, and the 32-member cabinet, the Federal Executive Council.
The president, who is both chief of state and head of the government, is elected by popular vote every four years and is limited to two terms. A candidate for president must be a Nigerian citizen by birth, at least 40 years old, a sponsored member of a political party, and have achieved at least a high school education.
Olusegun Obasanjo has been president since 1999, but concludes his second term in 2007 and is constitutionally ineligible to run again.
The Federal Executive Council, which includes the vice president and 30 presidential-appointed ministers, is chaired by the president and meets weekly to help formulate executive branch policy.
Legislative
Nigeria's National Assembly is a bicameral legislature comprised of the Senate and House of Representatives.
The Senate is made up of 109 members from 36 three-seat constituencies and one single-seat constituency in Abuja, the capital. Senators are elected every four years.
The House of Representatives currently has 360 members -- the constitutional maximum -- elected every four years.
The largely centrist People's Democratic Party holds the majority in both branches of the Assembly, winning majorities in both 1999 and 2003.
The National Assembly has the power to pass laws, even without the president's approval. Typically, a bill becomes a law once it is approved by both branches of the National Assembly and by the president.
Judicial
The Supreme Court is the highest federal court and has appellate jurisdiction over all state and lower federal courts. It is comprised of a chief justice and 21 justices, all of whom are nominated by the president and confirmed by the Senate. Supreme Court justices must be qualified to practice law in Nigeria, and have done so for at least 15 years.
Other courts at the federal level include a Federal High Court and a Court of Appeals, which sits in 10 judicial divisions throughout the country, but rules as a united body.
Because Sharia law, a system of Islamic law, is practiced at a state level in the north of the country, the constitution mandates that the Court of Appeals shall have "no less than three judges learned in Islamic law."
The Court of Appeals also hears cases on ethnic Customary law, which is a system of law handed down orally that reflects the values and traditions of the indigenous population, and must have at least three judges well-versed in the traditional law. Most of the cases tried under Customary law deal with family and marriage issues.
Each state also has a High Court, a Sharia Court of Appeal and a Customary Law Court of Appeal.
