I got...
Biology-
GCSE A (2 UMS of an A*)
AS - B
Chemistry
GCSE - A*
AS - C (I got an A and a D in exams, literally no revision)
Maths
GCSE - A*
AS - A (and probably A* at A2)
I completely fluked my GCSEs, I did very little revision (under 30mins for each in total), I decided to carry this on into AS which didn't turn out too great. I only did alright in maths as we had loads of mocks so ended up learning! If you are sensible and actually do work you'll be fine!
I would say A* in maths as FM, at least a B in each science but preferably an A especially if you're currently in top set and aiming for high A level grades!