Question 1 of Paper 5 asks you to plan an investigation: the apparatus, how each variable is changed, measured and kept constant, and the risks. These pages cover the experiment families that keep coming back. In each one, watch the set-up assembled step by step with the variables and the graph beside it, build it yourself on a bench, then check the wording the examiners want.
Catalase and hydrogen peroxide: a sealed tube, a gas syringe or inverted cylinder, a water bath and a buffer.
Like: 9700/51 June 2023
EnzymesTiming a colour or cloudiness change, with colour standards or a colorimeter, at a range of concentrations.
Like: 9700/52 June 2023, 9700/51 June 2025, 9700/52 June 2025
PhotosynthesisAlgal beads in hydrogencarbonate indicator, a lamp at measured distances, a heat filter and colour standards.
Like: 9700/53 June 2023, 9700/51 Nov 2024, 9700/52 Nov 2024
Transport in plantsCutting under water, an airtight seal, the bubble in the capillary and what is kept constant.
Like: 9700/51 June 2024, 9700/52 Nov 2025
EcologyRandom sampling with a grid, a belt transect from a fixed point, percentage cover and abiotic factors.
Like: 9700/52 March 2025, 9700/52 June 2024, 9700/52 Nov 2023
Biological moleculesJuice added to DCPIP until the blue colour disappears, a standard vitamin C solution and fair comparisons.
Like: 9700/51 Nov 2023
Investigation skillsMaking a dilution series with syringes, seeds on Petri dishes, an incubator and a fair test.
Like: 9700/51 Nov 2025
We read every 9700 Paper 5 Question 1 from 2023 to 2025, and grouped them by the apparatus they need. Each page is an original experiment in the style of its family, and every step carries what the Cambridge examiner reports said students got wrong.
Next: practise in the enzyme and osmosis investigations trainer. The experiments and wording on these pages are our own.