Honestly, I don't think minors matter to PT programs. PTCAS doesn't ask you to include them and I was never asked if I have any. I just wanted to chime in because I was a health promo major, bio minor and ended up switching to the bio major, health promo minor, and picking up a psych minor as well. I don't think the minors or my major had any impact on getting into school, but I will tell you that I feel they have all prepared me very well for PT school and the material I have learned has given me more to talk about in my interviews. Also, cell biology was the course that really interested me in biology, and if you enjoy biology I think cell is really awesome and helpful. It is something I will always have in the back of my mind in PT school. So, if you are interested in biology and feel you want to know more and have the time, I would go for finishing the minor. But honestly, will it affect your chances of getting in at least on paper? I doubt it. It's just a matter of what you are most interested in.