QCE Biology external exam: structure and technique

The external exam is 50% of your QCE Biology result and is sat as two written papers, each with 5 minutes perusal and 90 minutes working time, calculator permitted, covering Units 3 and 4. In 2025 the papers carried 101 marks between them: 20 multiple-choice marks and 29 short-response marks in Paper 1, and 52 short-response marks in Paper 2, which works out at roughly 1.8 minutes per mark in Paper 1 and 1.7 in Paper 2. Almost everything QCAA says about how marks are lost is about how students read and answer questions, not about how much biology they know.

Where the exam sits

Half your subject result comes from two papers. The 2026 Year 12 cohort, the first assessed under the 2025 syllabus for Units 3 and 4, sits them in October and November 2026. The other half is already banked by then, across the three internal assessments.

Only part of the syllabus is examinable here. Each of the four Unit 3 and Unit 4 topics splits into Science understanding and Science as a human endeavour, and it is the Science understanding dot points that are externally assessable. Science as a human endeavour is assessed internally.

Structure and the time budget

Two written papers. Each is 5 minutes perusal and 90 minutes working time, with a calculator permitted.

Total 101 marks in 2025. That split is reported in the subject report rather than fixed by the syllabus, so treat it as the shape of a recent paper rather than a guarantee for yours.

The useful thing to do with those numbers is turn them into a rate. Paper 1 carries 49 marks in 90 minutes, which is about 1.8 minutes per mark. Paper 2 carries 52 marks in 90 minutes, which is about 1.7 minutes per mark.

Multiple choice: the real risk is being confidently wrong

This is the part of the exam students most often assume is the easy part, and the 2025 data says otherwise for a handful of items.

QCAA publishes the percentage of the cohort choosing each option for every multiple-choice question. Here are the five hardest questions on the 2025 General paper, with the correct answer and the wrong option that drew the most students.

Percentages do not always total 100, because some students skipped questions.

Question 5 is the one to sit with. All three wrong options outdrew the correct answer, and only about one student in ten got it right. A pattern like that is not students guessing at random. It is a specific idea that most of the cohort held, applied confidently, and got wrong.

These are not trick questions, and QCAA does not describe them that way. Nothing in the report suggests the items were designed to mislead. What the numbers show is that a plausible-sounding misconception can be more attractive than the correct biology, which is an argument for checking your reasoning rather than for distrusting the paper.

Our own data points the same direction on where short-response marks go. Across 30,613 marked attempts on AusGrader in QCE Biology, multiple-choice questions average 72.0% (n=25,430) while short-answer questions average 68.1% (n=4,309). That is a self-selected sample of AusGrader users rather than the state cohort, so read it as corroboration, not as a cohort statistic. It is consistent with QCAA's message that the difficulty in this exam is concentrated in constructing answers.

What the 2025 cohort did well

Worth knowing, because it tells you which skills are already reliable across the state and therefore where a marginal hour of revision buys you least. From the report, students handled:

• Reading unknown values from graphs
• Interpreting graphs and tables, including inferring species relatedness from molecular data, reading a karyotype, interpreting ecological field data, and inferring carrying capacity
• Simple calculations, including the Lincoln index and quadrat-based population estimates
• Enzymes in DNA replication
• Species interactions

Note what that list is made of: extracting and interpreting information that is in front of you. That skill is in good shape.

What the 2025 cohort struggled with

QCAA names the content explicitly, and the pattern in the list is at least as informative as the individual items.

Describing. Key features of the Linnaean system. How climax communities differ from pioneer communities. The structure of plasmids and their role in recombinant DNA.

Explaining. Why molecular sequence data is better than anatomical data for determining relatedness. How populations change through natural selection. Why genetic drift is high in bottlenecked populations. How transcription factors allow cell differentiation.

Terminology, with three pairs named directly. Sex chromosome versus sex cell. Population growth versus population growth rate. Negative feedback versus homeostasis.

Numeracy. Rearranging equations, calculating percentages, determining ratios.

The pattern QCAA has named three years running

The strongest signal in the reports is not any single year's weakness. It is what appears again and again across the 2023, 2024 and 2025 cohorts.

Read the cueing factors before you write

Named in all three years, and the most persistent message QCAA sends about Biology exam technique.

• 2023: QCAA advised emphasising the importance of cognitive verbs and the number of marks when planning responses, giving the example that a comparison requires identification of similarities, differences and their significance.
• 2024: the advice expands to "cueing factors such as the cognitive verb, the number of marks, key terms in the question and relevant stimulus when planning responses".
• 2025: the same framing recurs through all twelve worked short-response items in the report.

That is four things to check before your pen moves: the verb, the marks, the key terms, and the stimulus. It is a technique problem rather than a knowledge problem, which is why it is worth practising deliberately.

Engage with the stimulus instead of generalising

Named in 2023 and again in 2025. The 2023 report asked teachers to give students more opportunity to respond to stimulus appropriately rather than making generalised statements. On the 2025 karyotype item, the report praises responses that referred to features in the stimulus rather than making generalised statements about aneuploidy.

Confusing closely related terms

Named in 2024 and 2025. The 2024 report singled out genetics terminology, giving allele versus gene as the example. The 2025 report adds sex chromosome versus sex cell, population growth versus population growth rate, and negative feedback versus homeostasis, and gene versus allele turns up again in its internal assessment commentary.

Describing and explaining under exam conditions

Named in 2024 and 2025, each with its own list of content. The 2024 list covers the role of tRNA, crossing over and genetic variation, energy transformation in an ecosystem, habitat fragmentation and speciation, DNA replication errors leading to point and frameshift mutations, regulation of gene expression, and primary versus secondary succession. The 2025 list is above.

Integrating knowledge to explain phenomena

Named in 2024 and 2025. The 2024 example is why genetic mutations do not always affect the phenotype. The 2025 examples are why molecular sequence data beats anatomical data for relatedness, and why genetic drift is high in bottlenecked populations. These questions require joining two ideas that are taught separately, which is a different task from recalling either.

The verb pattern, and what our data adds

Start with the board. QCAA named describing and explaining as weaknesses in both the 2024 and 2025 reports, and recommends more work on the numeracy underneath biology: rearranging equations, percentages and ratios. That is the finding.

Our marking data agrees from a different direction, and adds resolution the board does not publish. QCAA reports on content and skills; it does not publish an average score per cognitive verb. We can. Across 30,613 marked attempts on AusGrader in QCE Biology, against an overall average of 73.1%:

These are AusGrader users practising when they chose to, not the state cohort under exam conditions, so they support QCAA's finding rather than standing in for it. Two independent sources landing on the same verbs is the point.

Set that table against QCAA's own definitions of the cognitive verbs and a shape appears. The weak end (calculate, predict, compare, explain, describe) is made of verbs that ask you to produce reasoning or an account. The strong end (infer, identify, analyse) is made of verbs closer to recognition or a single step.

What the twelve worked items actually teach

The 2025 report works through twelve short-response items, and the striking thing is how little of its commentary is about biology. Across all twelve, the same process advice repeats:

1. Consider the cueing factors. The cognitive verb, the number of marks available, and the key terms in the question.
2. Engage with the stimulus directly, rather than making generalised statements.
3. Sequence ideas logically.
4. State a conclusion, then support it with reasoning and evidence.

That last one is worth taking literally. A conclusion on its own is an assertion. The reasoning is what converts it into an answer, and in a multi-mark question the reasoning is usually where the second mark lives.

Common mistakes

Answering the topic instead of the question. The generalised-statement problem, named in two separate cohorts. If your answer would fit any question on that topic, it is not engaging with this one.

Ignoring the mark allocation. The number of marks is a cueing factor QCAA names explicitly. It tells you how many distinct things the marker is looking for. A 3-mark question answered with one idea, however well expressed, is capped.

Answering a describe question with an explain answer, or the reverse. Both verbs sit near the bottom of our verb table, and QCAA names both as cohort weaknesses. Producing the wrong kind of account is a separate failure from not knowing the content.

Using the near-miss term. Population growth for population growth rate, sex cell for sex chromosome, homeostasis for negative feedback, gene for allele. All four pairs appear in QCAA's commentary.

Moving on from a multiple-choice question because the answer was obvious. On the 2025 paper's hardest item, the obvious answer was wrong for about nine students in ten.

Substituting into an equation before rearranging it. QCAA's numeracy advice is specific: rearranging equations, percentages, ratios. Our own data has calculate as the weakest verb we measure, at 55.7% across 268 attempts.

Weak versus strong responses

The left column is the pattern QCAA describes in its exam commentary. The right column is what the report says effective responses did instead. The content examples are the ones QCAA names as 2025 weaknesses.

What changed for 2026

Three things worth knowing if you are working from older material or past papers.

Perusal time is now 5 minutes, reduced from 10, across effectively every QCE subject. Any advice you read about a 10-minute perusal plan is out of date.

Calculator conditions have been clarified. A calculator is permitted in both papers.

Subject matter was revised, including changes to cognitive verbs. QCAA's own worked example of this is instructive: describe the modes of speciation became explain how geographic, temporal and spatial isolation influence gene flow and may lead to allopatric, sympatric and parapatric speciation.

Grade boundaries

Grade boundaries are set each year against the reporting standards, so they move. Across three recent cohorts every boundary shifted at least once: the A cut-off was 86 in 2023 and 87 in both 2024 and 2025, and the C cut-off was 49 in 2023 and 50 in the two years after.

For the 2025 cohort the boundaries were A 100-87, B 86-71, C 70-50, D 49-20 and E 19-0, and the state distribution across 13,961 students in 449 schools was 31.98% A, 47.99% B, 19.56% C, 0.47% D and no E results. Nearly 80% of the cohort achieved an A or a B.

Treat all of that as an illustration of one year rather than a target. A guide that tells you "87 gets you an A" will be wrong for somebody's cohort.

The other half of your result is the three internal assessments. See the IA1 data test guide, the IA2 student experiment guide and the IA3 research investigation guide, or start from the QCE Biology subject page to practise against real questions.