masters or phd or both?

[science1]

I graduated with my bachelors in functional biology (physiology concentration) last May. Early in my undergraduate career, my goal was to go to PA school so I focused alot more on getting experience in the healthcare field so I interned with physicians. It wasn't until my final year that I started doing research and switched gears completely. To confirm what I thought I wanted to do, I started working in the research/biotech field working primarily on cancer research and am now finally thinking about going back to school. My GPA is not stellar (2.99) and I got a 300 on my gre. My dream is to eventually get my phD and it would be ideal to directly apply and get in but am thinking thats kind of impossible for me.

Do any of you believe it may be more beneficial to get a masters first? and then apply to phD programs? if so, what kind of masters programs should I consider?

Research is what I live and breathe now, so want to make sure I am doing everything I can.