It depends.
Most medical school will allow a student to substitute an upper level bio with lab for an intro level class. But exact requirements will vary by school. You should consult the MSAR or the admission pages for every med school your child is interested in applying to in the future.
Chem requirements are more complicated. Your child cannot sub another chem class for ochem or biochem. Some schools will allow a student to substitute analytic, inorganic or physical chemistry for general chem if they have AP/IB credit for general chem. But again, you will need to check with specific schools.