Edexcel GCSE Maths - Linear/Modular

So, at my school we've already done Modular maths. I got a B. I'm resitting Unit 3, but my school's also entered me for Linear, too.

I was wondering: is what we need to know for linear different? I understand linear's a blend of all 3 units, but I'm inquiring as to whether you don't need to know AS MUCH content/theory for linear? Or do you still need to know ALL topics from the units?