Paper 2 Section A: short-answer and data-based questions

Section A of Paper 2 is a set of compulsory short-answer and data-based questions worth 40 marks. It has the same format and the same 40 marks at SL and HL, and it can draw on any topic of the course, from the foundation ideas of perspectives, systems and sustainability to urban air pollution. Questions are usually built around a short stimulus, such as a graph, a table, a photograph, a diagram or a few lines of text, and then split into parts worth 1 to 4 marks, with an occasional longer part.

Because every question is compulsory, Section A rewards breadth. There is no choice to hide a weak topic, and each mark is earned by a short, precise statement rather than by a long argument. The skills are learnable: reading the command term, counting the marks, writing one clear point per mark, handling data with values and units, and drawing clean diagrams.

How Section A is marked

Section A is marked with a question-specific markscheme. For each part, the markscheme lists the acceptable marking points, each worth one mark, often with more points than there are marks available. An examiner awards a mark for each valid, distinct point up to the maximum, and nothing for points that repeat, contradict or only restate the question.

Three consequences follow from point marking. First, the number of marks tells you how many separate points are needed. Second, length earns nothing on its own: a 4-mark answer with four precise sentences scores more than a page of general discussion. Third, a point must be specific enough to be recognisable as one of the markscheme points, so vague words such as “affects”, “harms” or “impacts the environment” rarely earn credit.

Each command term has a fixed meaning. What matters most in Section A is how the command term combines with the number of marks: “Outline two…” for 2 marks wants two brief points, while “Explain two…” for 4 marks wants two points, each followed by its reason.

What a mark looks like

The clearest way to see point marking is to compare three answers to the same question. All three students know the topic; only one writes in marking points.

Answer C also shows a useful habit: each point ends with the mark it is aiming for, at least in your head. When you can see where each mark will come from, you know the answer is complete.

A method for every short-answer question

A short routine, used every time, keeps answers focused and stops marks leaking away through misreading. It takes a few seconds per question once it is habitual.

1. Read the stem and the stimulus first. Note the place, the organism, the dates, the units and anything labelled “hypothetical”. Most data questions use only what is in front of you.

2. Underline the command term, the marks and the subject. “Explain how … [3]” needs three linked steps about exactly what follows “how”.

3. Count the marks and plan that many points. For 3 or more marks, plan one extra point in case one is not credited.

4. Write one point per sentence. Start with the point, then add the reason or the evidence. Avoid restating the question as an opening line.

5. Use course terms. Write “positive feedback”, “eutrophication”, “biochemical oxygen demand”, “transfer”, “transformation” where they fit: precise terms are often the marking points themselves.

6. Check numbers, units and the question. Is every value quoted with its unit? Has the answer given the number of items asked for, no more?

Question types and how to answer them

Section A questions fall into a small number of types. Each has a recognisable shape, and each has a typical way of losing marks.

Define and state

Definitions earn 1 or 2 marks and are where precise wording matters most. A definition should place the term in its category (“a storage of…”, “the process by which…”, “the maximum number of…”) and include the qualifier that makes it exact.

“State” items want a name, value or brief fact with no explanation. Adding explanation does no harm, but it costs time that longer questions need.

Outline and describe

“Outline” asks for brief points; “describe” asks for a more detailed account. In Section A the difference is mostly one of detail per point. A 4-mark “describe” question about a method expects the sequence of steps; a 4-mark “outline” question expects four distinct points.

Explain

“Explain” questions are where most marks are lost. An explanation is a chain: something happens, which causes something else, which leads to the outcome named in the question. Each link in the chain is usually one mark. Answers that state the outcome without the mechanism, or the mechanism without reaching the outcome, are incomplete.

Distinguish

A “distinguish” answer makes the difference clear for both items. Writing about one item and leaving the reader to infer the other usually earns only part of the marks. The safest structure is a pair of contrasting sentences, or a sentence with “whereas”.

Suggest

“Suggest” questions give an unfamiliar situation and ask for a reasonable answer. There is rarely one right answer: the markscheme accepts any plausible reason that applies course concepts to the stimulus. The skill is to use the information given rather than to recall a learned list.

Short evaluations

Section A sometimes includes an “evaluate” or “discuss” part worth 3 or 4 marks. These are marked by points, not markbands, but the points must include both strengths and limitations, and usually a brief judgement. A one-sided answer cannot reach full marks, however good it is.

Data-based questions

Many Section A questions open with data: a line graph, a table, a bar chart, a map or a short extract. The data are often hypothetical, invented to test a skill rather than knowledge of a particular place. The questions then move from reading the data, to calculating with it, to explaining it, to judging what it can and cannot show.

The graph shows the annual catch of a hypothetical fish stock. It is used in the worked examples that follow, which together cover the most common data skills.

Describing a trend

A description of a graph needs three things: the overall trend, the key values with their years and units, and any change of direction or anomaly. Writing “it goes up and then down” describes the shape but earns little, because it uses no data.

Calculations

Calculations in Section A are usually worth 1 or 2 marks: one for the working and one for the answer with its unit. The most common are percentage change, rates of change, means, the Lincoln index, Simpson’s reciprocal index, efficiency of energy transfer, natural increase and doubling time. Whatever the formula, the habit that earns the marks is setting out the working so that a marker can follow it.

A second calculation, typical of the population topic, uses rates given per thousand. The rule of 70 gives the doubling time.

Explaining and suggesting from data

After describing and calculating, questions usually ask why the data look as they do. The answer must still be anchored in the data: name the phase or value being explained, then give the reason.

Tables and comparisons

Tables often compare two sites, two years or two groups. “Compare” items need a statement about both, ideally with values, and a comparative word (“higher”, “three times”, “whereas”).

Correlation is not causation

Some questions ask whether data prove a cause. Two variables can change together because one causes the other, because both are caused by a third factor, or by chance. A strong answer recognises the relationship, then names the alternative explanation and what extra evidence would be needed.

Diagrams in Section A

Diagram questions use the command terms draw, label, annotate and construct. Each correct component earns a mark, so a diagram must be clear enough for a marker to find every one. In ESS the most common is the systems diagram: storages in boxes and flows as arrows labelled with the process, with inputs and outputs crossing the system boundary.

Using named examples in short answers

Some Section A parts say “with reference to a named example” or “for a named ecosystem”. These marks are only available if the example is named precisely and if a detail from it is used to support the point. One accurate, specific fact is worth more than a paragraph of general narrative.

Common ways to lose marks

A complete practice question

Section A questions are usually built as a sequence of parts on one stimulus. The question that follows is in that style, with a full model answer and the marks each part would earn.

Before moving to the next question

• The answer matches the command term: points for “outline”, mechanisms for “explain”, both sides for “distinguish” and “evaluate”.

• There are at least as many distinct points as marks, with no repeats or opposites.

• Every value from the stimulus has its unit and year; every calculation shows its working.

• Course terms are used exactly (transfer, transformation, positive feedback, carrying capacity, BOD).

• Diagrams have every box and arrow labelled.

• Named examples have a place, a date or a number, and a link to the point.