Applying for different majors... How should I go about my essays?

So I’m applying to the UC system except for some schools I’m applying as an Art major but others I’m applying as a biology major. If I do get into a school, I will end up either majoring or minoring in the other, but these two are very different majors so… how do I end up talking about what I want to do in the future (especially for Prompt 1!) without the schools being confused on what I actually want? The reason why I’m applying for two different majors is because I’m not exactly sure what I want to do yet… Thanks!