How to add dynamic controls to the mvc view

Dear Experts
I need an example for below task.
I have one registration form in mvc 4 . i have some dependency questions are also there in the registration form.so i have to go server after entering an answer for a question to store that answer and i will check i there any dependency question to enable based on the current question answer(dynamic questions). and i have only one field for many answers in model. in this case how can i accomplish this task. and how can i do validations.

Thanks
AnkiReddy