dropdown boxes

Wanting to create a multi-tier drop down list…

As follows:

Gender (dropdown box) , male or female. Once you click on the Male/Female option I want to be able to have another dropdown box beside the “Gender” which would say “Relational” with its own dropdown box showing its list of relevant terms referring back to “male”. If “female” is chosen then another set of relational terms would show in the “relational” dropdown box.

Any ideas?