Can I take a gap/year break between 2nd and 3rd year Biology?

I asked a few friends and said they believe that it's possible, but you have to have a good reason for wanting one for them to give you the chance.

My reason for wanting a year break between the 2nd and 3rd year of my Biology course is that I'm not 100% certain on my future career. I want 1 year to take on multiple concept art (drawings/paintings for film and video game industry) opportunities abroad and practice non-stop to be good enough to work freelance and earn money from individual commissions and working for companies.

Is this a good enough reason that they'll let me? It's important to me because it's to do with my future, and I'm not certain I want to follow a science career after uni. I feel as if though if they don't allow me, I might drop out after this year and not continue my final year.