Paper 5 · Question 1 · 9700/52 Oct/Nov 2023 · 16 marks

Algae in rocky shore pools: work it, then see the model answer.

Test rock pool depth against the number of algal species with Spearman's rank, then plan a belt transect across a rocky shore. Read the question, answer each part on paper, then work through it below and see how many of the 16 marks you would earn. The worked example shows a full-mark answer with the mark scheme point each line scores.

Past-paper referenceRephrased from Cambridge AS & A Level Biology 9700/52, Oct/Nov 2023, Question 1 (Paper 5, Planning, Analysis and Evaluation), for teaching. The figures, workout and worked example are ours.

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How Question 1 is marked

Variables and hypotheses

Identify the independent and dependent variables exactly as they apply to this investigation, and name standardised variables with how each is kept the same.

Method

A method in a logical order that someone else could follow: how the independent variable is changed (with values), how the dependent variable is measured, replicates, controls and a risk assessment that fits the procedure.

Data and graphs

Processed values to a consistent number of decimal places, tables with units in the headings, graphs with labelled axes, points joined with ruled lines or a line of best fit as the data need, and error bars when asked.

Conclusions and statistics

Say whether the data support the hypothesis using the actual figures, choose the right statistical test, state the null hypothesis and interpret the result against the critical value.

Habits that save marks

The question on this page is rephrased from a Cambridge International past paper for teaching. The figures, wording of the workout and the worked example are our own; the marking follows the published mark scheme. The original question paper is available from Cambridge.