Yea I have resat Core Science. Damn that was a long time ago.
I did it in year 10 and came out with 3 A's in all 3 sciences (I don't say that out of arrogance by the way, if it helps I ****ed up extension science lol), yet they called it 'core'. I wanted to do science at A level so I thought it would be best to get grades for the individual sciences (Biology, physics, chemistry) rather than (Core, Additional and Extension). In all honesty, if you're not going to do science at A level I wouldn't bother retaking, and even at B grades you can still probably get into whatever course you want to do. By retaking, I was put through 9 science exams, 3 pieces of coursework, in one year lol. Wasn't as bad as I though though.
Anyway, I'm going on here now. I did science at A level, chemistry and biology. In all honesty, I'm no longer a fan of the sciences, rather business and economics. Weird but everyone changes their passions once in awhile. Also, A level science I pretty much suck at lol.
Also, to the GCSE kids criticizing people for doing foundation, you higher lot are the foundation to me! Seriously, stop with your arrogance about whatever level you do. Everyone is different with respects to what they're good at. It is that arrogance and snobby attitude you hold which will undoubtedly lead you nowhere in life. Just focus on your own results and what you want.