# A student is investigating the effect of temperature on the rate of an enzyme-controlled reaction. They plan to measure the time taken for a substrate to be completely broken down at different temperatures. Describe how the student could ensure their results are reliable.

> OCR A-Level Biology A (H420) — 1 Development of practical skills in biology · Describe · 4 marks

## Mark scheme (4 marks)

1. Repeat the experiment multiple times at each temperature investigated.
2. Calculate a mean or average value from the repeated trials for each temperature.
3. Identify and exclude any anomalous results or outliers before calculating the mean.
4. Ensure all other independent variables are kept constant across all trials.

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-is-investigating-the-effect-edc8cc52) · Published by Druglandscape Ltd.