Is it possible to Major in Bio and have a Minor in Political Sci? Has anyone done this before?
And what does it mean to have a Minor.. Oh, and also.. if I have to take Political Sci courses in summer school, will that affect me in any way? (ie. If applying to MedSchool, will that have a negative impact on me, seeing that I took the courses in summer school?)

You can for sure minor in PoliSci here are the requirements: http://registrar.mcmaster.ca /CALEN...nt/pg1718.html
With all the elective space in honours bio it shouldnt be a problem... im also going into honours bio and im planning on doing a minor in origins. I have no idea what it means to minor in something other then getting the title of minor/the relevant skills you learn from those courses.

It also depends on the school but more from the aspect of whether they include these courses in your GPA calculation. Some count summer courses, some don't.