Do you advise I drop AS biology?

Hello! I'm an external student. I did AS levels in chemistry and physics and at the moment I'm working towards exams in A2 chemistry, A2 physics and both AS and 2 A 2 maths(doing full a level in one year). I added AS biology on, hurst because I thought it would look good, but I'm finding I spend most of my time on the other three and I'm wondering whether AS biology will just take my time and better grades away from the other three subjects. I was just shy of an A in chemistry and physics at AS so I really want to get am A this time. I've done some mocks for maths and I have had 90%, for core 1, 90% mechanics 1 and 87% for core 2. Currently working on core 3 and mechanics 2.
Any advice would be appreciated!

I did A level biology and got a D in it ten years ago, not sure whether that could count, also AS law but it was a grade D also. I'm wondering whether 1 A* and 2As will be enough to get me into a good uni?

10 years ago wut? anyway those count but arnt good enough for a forth AS and 1 A* and 2 A's will get you into top unis i think you should do AS bio and just aim for a C

Yes ten years ago! I'm external student wanting to go to uni

im guessing you'll have around 10-12 exams so I would focus on the others until you understand everything then go onto bio so it doesn't affect the others or you could always spread out your revision for all your exams so you perform well in all of them when do you plan to start to revise?