The prerequisites for medical school are(more or less the same for every school, some are a little different but they are basically the same):
Biology 1 with lab
Biology 2 with lab
Inorganic chemistry 1 with lab
Inorganic chemistry 2 with lab
Organic chemistry 1 with lab
Organic chemistry 2 with lab
Physics 1 with lab
Physics 2 with lab
Calculas 1 (depending on which school)
English 1 & 2 (also depending on which school)
& a bachalers degree is needed also with all of these prereq’s
You also need to take the MCAT.
For law school all you need is a bachelors degree & you have to take the LSAT.
I am not sure what you need for business school but I think all you need is a bachelors degree & you have to take the G-MAT