So is it better to take bioligy A-Level even if the college requirements doesn't ask for it?

So I'm in year 11 now and my college faculty of biotechnoligy, requires 8 O.Levels only, so far I have 6 done and now in year 11 taking Bioligy A.S and 2 more O.L, so my question is, if my college revisits all the topics from scratch basically and only builds up from O.L should I spend another year at year 12 to take A2 bioligy to have the upper hand or should I just go to college? What do you think?