Answer:
Advantages:
An advantage of unitary government are that it is a single and decisive legislative. Also, a unitary government is very simple system, and as such less costly to run. Another advantage of a unitary government is that the laws of the unitary system, unlike in a federation, are uniform because laws are made only by a single central government for the whole state.
Disadvantages:
A disadvantage of using this type of system is that it has slow government response. For example, there are no state defence forces that could be dispatched in cases of emergency. Troops would have to be mobilized by national authority. It is also easily loses track of local issues. Also, it is quite a divisive form of government where everyone is forced to compete with everyone else for priority.
Hope that helps....