You do not need Higher English. You do not need Higher Maths.
The only Higher you must have is Chemistry. Most universities say that you should have two or three science subjects of which maths is counted.
Personally, I think maths and English should be taken...simply because they are useful for life in general. Most applicants will have one of three subject combos in fifth year:
1. English, Maths, Chemistry, Biology, Physics- I find this combo very limiting but probably the most popular.
2. English, Maths, Chemistry, Biology, History/Geography/Mod Studs/Language
3. English, Maths, Chemistry, Physics, History/Geography/Mod Studs/Language- I took these subjects and don't regret it for an instant.
YOU DO NOT NEED ADV HIGHER BIO.
I chose to take Higher Biology in sixth year along with my three Advanced Highers. This is possible but taking 4 subjects in sixth year is dependent on school policy.