3P.8—Processing and analysing practical data

Processing data means converting measurements into a form that answers the question: check units, calculate the required quantity, summarise repeats and compare the result with a control or prediction.

Use means when repeats represent the same condition, calculate a proportion or index with the correct numerator and denominator, and report appropriate significant figures. Keep raw values available so a calculation can be checked.

For a mitotic index, count cells with visible chromosomes, divide by total cells and state whether the answer is a proportion or percentage. For a clear zone, calculate area from radius rather than diameter.

Rounding too early can change a conclusion, and an average can hide a skewed or contaminated sample. State the mathematical operation and the biological meaning of the output.