Why is a minaret an important feature of a mosque?

Yes, call for prayer can be done from anywhere but you to have a fixed place from where you can call for prayer and that people can know about it so that they can congregate and pray together. Islam believes in unity, one brotherhood standing shoulder to shoulder no rich no poor, believes in one heart. 

Minarets are not very important but they serve as an identity of a mosque so that people will know that this is the mosque. That is it. 

Upheld the 1st amendment according to the u.s constitution. freedom of speech being limited in this case yes national emergencies

The constant presence of diseases or infectious agents within a given geographic area or population group. it may also refer to the usual prevalence of a given disease with such area or group. it includes holoendemic and hyperendemic diseases. a holoendemic disease is one for which a high prevalent level of infection begins early in life and affects most of the child population, leading to a state of equilibrium such that the adult population shows evidence of the disease much less commonly than do children (malaria in many communities is a holoendemic disease). a hyperendemic disease is one that is constantly present at a high incidence and/or prevalence rate and affects all groups equally. so probably family history.