SPM Biology Paper 2 Section A: structured questions
Section A (60 marks, 8 questions (answer all)) rewards short, precise answers matched to the marks shown, read the number in brackets before you decide how much to write.
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What Section A involves
Section A is made up of 8 questions (answer all), each broken into sub-parts such as (a), (b)(i) and (b)(ii). Sub-parts move from simple recall to application, and most are built around a diagram, a set of results or a short data table that you must read before answering.
Because it carries Section A: 60 marks, more than half of Paper 2's total, Section A is where careful, disciplined answering has the biggest effect on your overall score.
Reading the mark allocation
| Marks shown | What the examiner expects |
|---|---|
| [1] | One correct term or fact, stated clearly |
| [2] | Two distinct points, or one point plus a linked reason |
| [3]–[4] | Two or more distinct points, or a full explanation with more than one step |
Command words you meet in Section A
The command word in each sub-part tells you what kind of answer earns the marks. Answering the wrong command, explaining when asked to state, or describing when asked to explain, is one of the most common ways to lose marks you actually knew.
| Command word | What to give |
|---|---|
| State / Name | One correct term or fact, with no explanation |
| Define | The exact meaning of the term, using its key phrases |
| Describe | What is seen or what happens, in order, without the reason |
| Explain | The reason or cause, an answer built on "because" |
| Calculate | A worked answer with the steps shown and the correct unit |
| Suggest | A biologically reasonable idea applied to a new situation |
| Compare | A similarity or difference stated for both items, not one alone |
Answering data and diagram sub-questions
- Read the diagram, table or graph fully before answering any sub-question that refers to it.
- When asked to describe a trend, name the direction and quote actual figures with units from the data, a trend stated without figures rarely earns full marks.
- On a graph, check the axis labels, units and scale before reading off any value.
- For diagram labelling, use a ruled straight line that touches the exact structure, and spell the term correctly.
Calculations and graph plotting
Section A often includes a short calculation, a rate, a percentage change or a magnification, and a graph to plot. Both reward method, not just the final figure, so show every step even when the arithmetic is simple.
- For a calculation, write the formula, substitute the figures, then give the answer with the correct unit; a right number with no working can lose the method mark.
- For a percentage change, use the change divided by the original value, then multiplied by one hundred, and state whether it is an increase or a decrease.
- When plotting a graph, label each axis with its quantity and unit, and choose a scale that fills more than half the grid.
- Plot each point precisely with a small cross or dot, then draw a single best-fit line or a smooth curve rather than joining points dot-to-dot, unless the data are discrete.
A worked structured sub-question
Question. A student counted the oxygen bubbles released each minute by a piece of pondweed as a lamp was moved further away. Results: 10 cm gave 60 bubbles per minute; 20 cm gave 32; 30 cm gave 15; 40 cm gave 8.
(a) State the process that releases the oxygen. [1] (b) Describe the relationship between the distance of the lamp and the rate of bubbling. [2] (c) Explain, in terms of light intensity, why the rate changes as the lamp is moved further away. [2] (d) Suggest one variable the student should keep constant for a fair test. [1]
Model answer. (a) Photosynthesis. (b) As the distance of the lamp increases, the rate of bubbling decreases; the fall is steepest between 10 cm and 20 cm, from 60 to 32 bubbles per minute.
(c) Moving the lamp further away lowers the light intensity reaching the pondweed; light is a limiting factor, so less light means a slower rate of photosynthesis and fewer oxygen bubbles. (d) Keep the temperature constant (or the carbon dioxide concentration, or use the same piece of pondweed).
Common mistakes in Section A
Source:SRC-FORMAT
Frequently asked questions
How many marks does Section A carry?
How do I know how much to write for a Section A question?
What do the command words in Section A mean?
How do I show working in a Section A calculation?
What should I do with a data table or graph in Section A?
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