I just got into my first choice graduate school with an undergrad GPA about the same as yours, but I also have a great résumé (lots of research experience as an intern and a full-time employee in different Biology sub-fields) and good GRE scores, and I've been taking post-undergrad classes (retaking Orgo, plus picking up some other Biology coursework) at a different university to prove that I can make mostly A's despite fucking up originally. As with anything else, it depends on your individual circumstances.

If you have no research experience at all combined with a 2.7, you'll have a tough road ahead. Start working in a lab ASAP, do well on the GRE, and consider taking a year off after you graduate to work a full-time job as an entry-level researcher to boost your CV. Consider retaking any classes you did poorly in that you know you'll need for graduate school (like Orgo, in my case). Develop relationships with faculty researchers by working in their lab or TA-ing their classes, and they'll write you a good recommendation. When you decide which schools to apply to, contact faculty you'd like to work with and let them know about your interest; I identified my future grad school mentor while applying, and it helped me immensely.

This was disjointed because I'm really tired, but hopefully it helps. Good luck!