PhD and First Year BSc Grades
pg: PhD programs care much more about recommendations than grades.  The most important thing you can do is get a good recommendation from a professor at your school who's known to whoever you want to work with at the target school.As for grades specifically, you can probably just tell them the truth, which is that you screwed up freshman year.  Grad school admissions are done by smart people (usually the profs themselves).  They'll realize that if you got good grades in the later, harder classes, you could have done well in the easier ones.