1. What is the difference between federalism and unitary system of government? Provide examples of countries that use each system. - Federalism is a system of government in which power is divided between a central authority and various constituent units, such as states or provinces. Unitary system is a system of government in which all power is concentrated in a single central authority. Examples of federal countries are the United States, Canada, Germany, and India. Examples of unitary countries are France, Japan, China, and the United Kingdom. 2. What are the main functions and powers of the U.S. Congress? How are they distributed between the two chambers, the House of Representatives and the Senate? - The main functions and powers of the U.S. Congress are to make laws, represent the people, oversee the executive branch, conduct investigations, and declare war. The powers are distributed between the two chambers according to the principle of bicameralism, which means that each chamber has different roles and responsibilities. The House of Representatives has the power to initiate revenue bills, impeach federal officials, and elect the president in case of a tie in the electoral college. The Senate has the power to ratify treaties, confirm presidential appointments, try impeached officials, and approve or reject judicial nominations. 3. What are the main features and principles of the U.S. Constitution? How can it be amended? - The main features and principles of the U.S. Constitution are federalism, separation of powers, checks and balances, judicial review, popular sovereignty, limited government, and individual rights. The Constitution can be amended by two methods: either by a two-thirds vote of both houses of Congress followed by ratification by three-fourths of the states, or by a national convention called by two-thirds of the states followed by ratification by threefourths of the states. 4. What are the main types and functions of interest groups in American politics? How do they influence public policy and public opinion?