9700/21/O/N/25 · Biology October/November 2025 Paper 21
6 questions, 60 marks. Each one links to its official mark scheme.
- Question 1 · 9 marks · Fluid mosaic model, Diffusion, osmosis and active transport
- Question 2 · 12 marks · Haemoglobin, Oxygen dissociation curve, Arteries, veins and capillaries, Cardiac cycle
- Question 3 · 10 marks · How enzymes work, Food tests, Measuring enzyme activity, Inhibitors
- Question 4 · 12 marks · Sugars and glycosidic bonds, Prevention and control, Antibiotics
- Question 5 · 8 marks · Xylem and phloem cells, Transpiration, Xerophytes, The cell cycle
- Question 6 · 9 marks · Genes and the genetic code, Transcription and translation, Water potential, Functions of the tissues
Questions and mark schemes from Cambridge International past papers. Paperstreak isn't affiliated with Cambridge.