My Science School

 In Latin, 'camera' means chamber and 'bi' means two. So, a bicameral parliament has two chambers, and a unicameral parliament has only one chamber. Bicameral legislatures are common in federal systems - a system in which a group of regions is controlled by a central government. The United States is an example. Generally, bicameral legislatures require a majority from both houses to pass a law.

Unicameral legislatures are common in communist states such as China and Cuba. Many former communist states such as Ukraine, Moldova and Serbia have retained their unicameral legislatures. Others such as Russia and Poland have adopted bicameral legislatures after the fall of communism. In unicameral systems, law making is efficient, simple and cost effective. The lack of 'checks and balances' is a drawback of the bicameral system.