I'm a non-science major and have only taken the usual bio/gen/orgo/physics classes. The classes were huge (around 600 kids) and though I occasionally went to office hours, I never made a big impression on the professors (various reasons, but mainly I worked so much that I just didn't have time to go to campus wait in line and what not, just to get a quick answer. Anyway, the professors will only write a letter if you did fantastically in the class. I've had around a B+ average in these classes with a couple of A-'s so they basically all said they were sorry but its not their policy. My school does have a committee letter, and I submitted very positive letters from a research adviser (psychology study) the dentist I worked with and the head of the masters program for psychology (my major). However, I'm really at a loss about a science letter. Should I take extra science courses, as I'm taking a lag year? What would be your advice in this situation?