As Gerry Myerson points out in a comment to your question, you should ask the appropriate people at your university. Since this is a late answer to your question, I hope you have already done so, but perhaps this answer will benefit others.
Searching online for applied mathematics programs in biology reveals many courses (e.g. Brown University's Applied Mathematics - Biology degree.)
Certainly, calculus, linear algebra and probability are fundamental subjects. Statistics and differential equations are also important. For computational biology, discrete mathematics, especially graph theory and combinatorics can be valuable.
At an advanced level you may run into various subjects from partial differential equations to nonlinear dynamical systems to stochastic processes to computational topology to algebraic statistics. What to choose will depend on degree requirements, what is available at your university and the advice of experts in the area. I would also recommend asking about taking suitable biology courses and other subjects, such as programming, algorithms, chemistry and physics.