It is perfectly possible to do well at A-level in chemistry, biology or physics, without studying maths at A-level (although in the case of physics this requires support, either through "maths for scientists" courses or from the subject teacher during science lessons.) The next stage is much more difficult. Physics and engineering are completely out as degree options without A-level maths and a background in A-level maths is of great benefit to undergraduates in chemistry, biology or biochemistry.
One of the benefits of the ASA2 system is that more students are doing maths alongside science and therefore have an opportunity to study calculus, for example. It is very important, for the long-term future of the pure sciences at university that A-level maths is "stimulating, appropriately-challenging, enjoyable and eventually rewarding". If not, there will be more vacancies being advertised next August as fewer students are appropriately-qualified or fewer universities are able to sustain chemistry and physics departments.
Kris Stutchbury Head of science, King's School 1 Shrigley Rise, Bollington Macclesfield