You’ll need a year (two semesters) of Biology, Chemistry, Organic Chemistry and Physics, with the accompanying labs. Most schools require applicants to take one or two courses in English, Calculus and the Social Sciences too. There is some variation from school to school, so check with your advisors.
For the MCAT, courses in Genetics, Anatomy, and Biochemistry can be helpful, but they’re not required or neccessary (I did just fine without them). Post-2015, there’s a different looking landscape, including an emphasis on cellular and molecular biology, plus genetics and biochemistry. It may be a fair trade, since the second semester of organic chemistry, the emphasis on physics, and the writing section are going away. Other additions include entry-level classes in psychology and sociology, in order to ensure that future doctors are well-equipped to understand and communicate with patients, and understand socio-cultural and behavioral effects on health. It’s a good idea to check with a pre-med counselor to confirm which courses at your school fulfill the required pre-med coursework. You might also want to contact medical schools you could see yourself applying to, to be sure they don’t have any special requirements like “Gender Politics in 18th-century Tuvalu” or something we haven’t mentioned here.  It’s unlikely, but there are a few schools that do.