Im assuming you are in year 13. If you need THREE A's to get on your course, and you are worried that you might not get 3 A's, i suppose there are 2 things you can do. You can drop biology and you DEFINITELY won't get 3 A's. Or you can push on, put some work in and you have A CHANCE to get 3 A's. I suppose there is a bonus mystery 3rd option, where you don'd drop it, but don't try too hard in it and just see if you can at least pass. But there is time to turn this around. Don't lose hope and don't be disheartened by getting a B in year 12!!