pretty much bio-research, if you arnt lucky with 1-2 years before graduation you are out of luck.(seats in labs are very limited in universities), many PI got burned by volunteers flaking on the duties, so they resist even mentioning lab work to potential students. also labs predominately prefer 1 demographic over another. and entry levels wont entertain you for a job, because its became a catch 22.

or some people love 1 major but cant seem to grasp the pre-req classes, as in passing them. i knew one that kept trying, but thier advisor told her to just give up because you arnt doing so well.