Most decent PhD programs in biology will guarantee 5 years of funding (tuition plus stipend on the order of 22K-30K / year) , with the provision that you may have to work as a teaching assistant 20 hours/week for some or all of that time.
The challenge will be getting into one of these programs with a 2.7 GPA. Many graduate schools require a minimum GPA, often around 3.0, for admission. Departments can and do petition to admit students with lower GPAs, but it certainly makes things harder. Being an underrepresented minority can be helpful if there are other strong aspects to your application that compensate in part for the low GPA.
As you've indicated, doing research is one possibility. Publishing a result would be great; simply being a lab for an extended period of time working alongside a PI is already a good thing. Why? It shows that you know what research is about, and it enables you to get a letter of recommendation from someone who knows you well in a research capacity.
What else can you do? Letters of recommendation are very important; do you know faculty from who you could get strong letters? If not, start making those connections now. A good GRE score will go a long way toward compensating for poor grades. It's worth preparing thoroughly for the GRE before you take it. Contacting possible advisors at the schools to which you are applying is extremely important. You can find lots of advice about how to go about doing that here on this site.
Good luck. While you're not in an optimal position, we've taken students with GPAs in your range at our top-20 PhD program, so certainly there is hope.
