Graduate school applications and pass/fail credits during undergrad?

[argentnox]

I am really nervous about having several pass/fail credits on my transcript for graduate school applications. I am trying to pad my application with a few select courses (human genetics, human bio, biochem or o-chem, humans in the environment) and get A's in order to essentially say, "Look, I can handle science courses just fine, it was just less expensive and time consuming to take several exams for credit rather than all courses." I also have some regular courses (all of my minour is from coursework, and I have some other credits from coursework...see my signature), all A's.

I am sitting on a 4.0 at the moment, with my name on the President's List for the past spring semester.

I should have solid letters of recommendation (one from a history professor that absolutely LOVES me, one from a psych professor that I spent a ton of time after class with--discussing the subject just because it was interesting, and hopefully one from either a researcher if I can manage to get research experience or from a biology professor).

I have a lot of volunteer time, both relating to biology and otherwise. I also intend to try to pack in some more. I will be helping underprivileged elementary students with biology once my background check clears (I do not foresee any problems there, just that background checks take forever).

I also did a lot of bio-related extracurriculars in high school. I raised and showed rabbits, poultry, and dogs. I was in 4-H and FFA (held leadership positions in both). I volunteered at University of California Davis small animal AND equine vet centres.

I am just really worried that the pass/fail credits will look like holes, especially since quite a bit of my majour credits are coming from the GRE. Plus, I am not likely to have the advantage of having any research experience because I have had to work and go to school throughout my entire degree. People want research assistance from people who can come on weekdays, during the day, not evenings or weekends.

Any tips for making my application more impressive to offset the pass/fail credits from exams? I want to get into the Molecular Biosciences program at University of Chicago, if at all possible.

I am closing in on one year (or less) until my undergrad degree is done, so I am really trying to make sure I get everything I need in.