From what I've heard, first-year physics at UoM is comparatively poorly taught and fairly difficult (before the upscaling that tends to occur, mercifully, unlike in calculus and chemistry). I reckon you should be able to get Physics in, though; you have 5 spots taken up during first year without Physics (since Linear Algebra is in summer). You could take both Physics 1 and 2 AND get a breadth completed, and after summer semester you'd only have 15 subjects left within your degree. However, for postgraduate engineering, Calc 2 and Linear Algebra are all you need for SOME of the postgraduate engineering courses (they tend to need 2 first-year subjects in a relevant discipline, like physics, computer science etc. but I'm assuming you're not planning on software eng so first-year physics, chem and bio would cover most all of them), so from that point you could focus on your MD prerequisites and whichever major you choose. Your major is completed in 3rd year and is comprised of four subjects out of the degree's twenty-four. However, most subjects involved in your major will have prerequisites. After first year, you will have an idea of your desired major and should then choose appropriate second-year subjects to fulfil third-year prerequisites. Doing life sciences, chemistry, maths and physics in first year opens you up to a lot of majors; aside from earth sciences and geography you can do just about everything!