HSC Biology exam 2026Exam: Wed 21 Oct · NESA timetable
Your HSC Biology exam:
When and how long
- Biology9.25 am to 12.30 pm3 h plus 5 min reading time
NESA: the exam start time shown on your timetable is when reading time begins, and you must arrive well before it. Finishing times marked approximate are shown as approx.
Source: 2026 HSC written exam timetable (NESA), checked Wednesday 23 September 2026. Where a start time, reading time or duration isn't shown, the timetable doesn't publish it: check your personal timetable and the front of your paper.
Paper format
Higher School Certificate Examination - Biology: 100 marks, 3 h writing time plus 5 minutes reading time.
- Section I - Objective response20 marks
- Section II - Short answer and extended response80 marks
NESA HSC exam specification for the Biology Stage 6 (2017) syllabus: 3 hours plus 5 minutes reading time, 100 marks. Section I is objective-response questions worth 20 marks. Section II is worth 80 marks: 20 to 25 items (questions may contain parts), at least two of them worth 7 to 9 marks. There is no Section III. The time split per section is our suggestion.
From the official specification: source.
Most-examined dot points
From 303 questions on the official NESA papers (2019 to 2025), mapped to the syllabus. Past frequency is a guide to what to secure, not a prediction.
- Meiosis and gamete formation explained36 questions · examined in 7 of 7 years
- Homeostasis, feedback, thermoregulation and osmoregulation23 questions · examined in 7 of 7 years
- Epidemiology: incidence, prevalence, mortality and study designs18 questions · examined in 7 of 7 years
- Biotechnology applications in agriculture, medicine and industry16 questions · examined in 6 of 7 years
- Types of mutation: point, silent, frameshift and chromosomal16 questions · examined in 7 of 7 years
- Mutation, gamete variation and the source of new alleles14 questions · examined in 7 of 7 years
- Local, regional and global strategies to limit disease spread14 questions · examined in 7 of 7 years
- Transcription and translation explained13 questions · examined in 6 of 7 years
Night-before and exam-morning checklists
The night before
- Check your personalised timetable on Students Online: the start time shown is when reading time begins.[2]
- Confirm your venue and the start time.[1]
- Pack a clear bag: several black pens (no erasable ink), 2B pencils, sharpener, eraser and a ruler.[1]
- Pack an approved calculator (check NESA's list) and a compass or protractor if the exam needs them.[1]
- Fill a clear, label-free water bottle.[1]
- A plain watch only if you want one (no smart or programmable watch); it goes on the desk.[1]
- Stop revising around 7 to 8 pm, set two alarms and sleep.[1]
Exam morning
- Eat a real breakfast.[1]
- Arrive well before the start time to allow for seating and checks.[2]
- Leave your phone and other electronic devices outside the exam room.[1]
- Use the bathroom before you go in.[1]
- In reading time, read and plan only: no writing, marking or annotating.[1]
- You can't leave in the first hour or the last 15 minutes.[1]
Exam-week survival kit: The last 7 days · The night before and exam morning · What to bring, and what's banned · How to use reading time · If you're sick or something goes wrong · Handling exam-week stress.
Last-week revision
- Timed mock examHigher School Certificate Examination - Biology
- 2025 past paperWalkthrough, with a link to the official NESA paper
- 2024 past paperWalkthrough, with a link to the official NESA paper
- 2023 past paperWalkthrough, with a link to the official NESA paper
- 2022 past paperWalkthrough, with a link to the official NESA paper
- Exam trendsEvery dot point by how often it is examined
- FlashcardsSpaced-repetition cards from the syllabus pages
- QuizInfectious and non-infectious disease (Modules 7 and 8)
- QuizExam-style practice (harder): Biology multiple choice
- QuizHeredity and genetics (Modules 5 and 6)
- Study guides7 guides
Syllabus by module
HSC Biology cram sheet
Key formulas, definitions and facts copied from our Biology syllabus pages, most-examined topics first. One page when printed.
Module 5: Heredity
Meiosis halves, fertilisation restores. A diploid (2n) germ-line cell divides twice to give four haploid (n) gametes; fusion of two haploid gametes at fertilisation rebuilds a diploid (2n) zygote. This is what keeps the chromosome number constant across generations.
DNA replication is semi-conservative: each daughter helix keeps one parental strand and gains one new strand. Because DNA polymerase only builds 5' to 3', the antiparallel templates force a continuous leading strand and a discontinuous lagging strand of Okazaki fragments sealed by ligase.
A male has only one X chromosome, so he expresses any allele on it. For an X-linked recessive trait the genotypes are: females (unaffected), (unaffected carrier) or (affected); males (unaffected) or (affected). There is no male carrier state.