Problems with AQA A level biology Watch
That's just over two-thirds of the marks for an A*. Half marks will get you a comfortable B. Other exam boards show similar figures.
62% in the context of most exams you'll be used to sounds pretty bad, but in reality it's a comfortable A, coming up to A*. When you're marking past papers, make sure that you look at the grade boundaries to give yourself an accurate picture of how well you did in relation to everybody else.