Final answer:
The United States has two court systems: state and federal. The federal system is not the only one with appellate courts, and it is not the only one based on the constitutional doctrine of separation of powers. The federal system, however, does have judges who are appointed to office.
Step-by-step explanation:
The United States has two court systems: state and federal. The federal system is not the only one with appellate courts, as both state and federal systems have trial and appellate courts. The federal system is not the only one based on the constitutional doctrine of separation of powers, as both state and federal systems are based on this doctrine. The federal system, however, does have judges who are appointed to office, whereas in some state systems judges may be elected by the public.