Depends what exam board you will be on. I do AQA A Level Textiles and I finished my last exam today - HELL!
Textiles was not what I was expecting, I'll put it that way. I did nothing for my GCSE Textiles and came out with a A, so I decided to take it. A Level Textiles consists of a Science section, talking about molecules in materials, linear structures of fibres and oxidisation for dyeing. There's then an ICT/Manufacturing section, talking about tons of different systems used to plan, make and distribute. Then there is a designer and history section. Just because they are in sections, doesn't mean something from all of them come up. I got the highest in the class last year for a D in the exam. I worked so hard this year for my next one and nearly cried when I got out today. Bye bye University! The coursework is fun but sooo much work, takes 80% of your time.
Then again this is just my opinion and I don't know what Graphic Design is like, so I can't compare. But based on my experience, big no no!
Be prepared, it's a lot of work, a lot of info and very broad!