If I dont know health or death history of a parent how do I answer life insurance questions?

It is very simple. You answer "Unknown". If you want to comment, you can always go to the section of application down below that says "Additional Comments" or something like that and explain why it is unknown (i.e. both parents died when you were a little child, or parents were divorced and you lost track of your dad, or anything else). However, you do not have to explain much. If underwriters of the company that you are applying with, have these additional questions they will call you to conduct a brief phone interview. It is a normal practice with reputable companies and you don't need to be worried if they call. Hope this helps. Sincerely, FH