There were quite a few GCSE Biology exams today, including the following and possibly more.
Edexcel GCSE Biology Paper 1 (Foundation Tier)
Edexcel GCSE Biology Paper 1 (Higher Tier)
Edexcel IGCSE Biology Paper 1
OCR GCSE Biology Paper 1 (Foundation Tier)
OCR GCSE Biology Paper 3 (Higher Tier)
AQA GCSE Biology Biology Paper 1 (Foundation Tier)
AQA GCSE Biology Biology Paper 1 (Higher Tier)
To which are you referring? Or are you asking generally - i.e. across all of them?