Practise Edexcel IGCSE Biology Movement of substances into and out of cells with exam-style questions for IGCSE Biology. 23 questions, matched to the Edexcel IGCSE Biology (4BI1) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.