How can all DNS servers be integrated without upgrading the servers to windows...

[Sarah C]

...server 2003? It has been decided that the university will not replace the UNIX DNS servers with windows server 2003. It has also been discovered that a few small departments also have windows NT 4 servers running DNS. In order to reduce replication traffic, not all windows server 2000 domain controllers will run as DNS servers. In addition, some windows server 2003 member servers will run DNS. The head of the computer Services Department recommends that only active directory-integrated zones be created to reproduce administrative and managment overhead. What are the implications of such a decision and how can all DNS servers be integrated without upgrading the servers to windows server 2003?

This is the last week of my networking class and this is part of my homework this last week. I'm so confused atm about DNS and Zones. While studying for my final its a bit overwhelming. If anyone has and idea on where to go with this question, it would be very much appreciated.