BOS, for some reason, does not release sample answers; only books that contain student answers. Even in these they don't tell you exactly what mark the answer got, they just tell you the band range that the answer is in...
The best thing you can get is to buy the Success One Book. The answers in there are written by science teachers and, according to the authors, would have resulted in full marks. Though I am a bit sceptical of some of their answers, they go waaaay too much in depth at times and dont even relate to the question properly at other times. But generally they are very good answers.
