How does the governmental and social structure of the Greek-city states

Option 1

How does the governmental and social structure of the Greek-city states (especially that of Athens) in the Classical Age compare to that the Roman Republic? What were the major problems, societal and otherwise, that they faced that led to the eventual collapse of democratic and Republican styles of government in both Greece and Rome?

Option 2

Compare and contrast the roles of religion in the Islamic, Byzantine, and western European worlds in the period 300-760. How central was religion to governmental and/or societal structure in these areas during those 460 years?