WACE Human Biology most tested topics
Across the six SCSA Human Biology external papers from 2020 to 2025, Central and peripheral nervous system carries 14.7% of the marks against 1.7% for Science Inquiry Skills (Unit 4), so the paper rewards Central and peripheral nervous system more than any other topic. At dot-point level 4.6.1 carries 6.8% of paper marks, and three of the 58 dot points that the board assesses externally have not appeared in one of these papers. Every percentage below covers the 99.2% of marks that map to a syllabus dot point.
Computed from 6 SCSA Human Biology external papers, 2020 to 2025: 243 questions, 478 question parts and 1294 marks.
Unit, topic and dot-point shares below are of the 1284 marks that map to a dot point, so each of those tables adds to 100%. 131 of the 478 parts are assessed against more than one dot point, and their 466 marks are divided evenly between the dot points they cover.
What these papers are
| Year | Exam | Questions | Marks |
|---|---|---|---|
| 2025 | Exam | 40 | 216 |
| 2024 | Exam | 40 | 216 |
| 2023 | Exam | 40 | 217 |
| 2022 | Exam | 40 | 209 |
| 2021 | Exam | 41 | 216 |
| 2020 | Exam | 42 | 220 |
Marks by unit
| Unit | Share of marks |
|---|---|
| Unit 3: Homeostasis and disease | 54.3% |
| Unit 4: Human variation and evolution | 45.7% |
Marks by topic
| Topic | Share of marks | Papers it appears in | Years |
|---|---|---|---|
| Central and peripheral nervous system | 14.7% | 6 of 6 | 6 of 6 |
| Hominid evolutionary trends | 14.3% | 6 of 6 | 6 of 6 |
| Response to infection | 12.0% | 6 of 6 | 6 of 6 |
| Homeostasis | 11.9% | 6 of 6 | 6 of 6 |
| Evidence for evolution | 10.4% | 6 of 6 | 6 of 6 |
| Gene pools | 7.6% | 6 of 6 | 6 of 6 |
| Science as a Human Endeavour (Unit 4) | 6.3% | 6 of 6 | 6 of 6 |
| Endocrine system | 6.1% | 6 of 6 | 6 of 6 |
| Science Inquiry Skills (Unit 3) | 5.4% | 6 of 6 | 6 of 6 |
| Mutations | 5.4% | 6 of 6 | 6 of 6 |
| Science as a Human Endeavour (Unit 3) | 4.1% | 6 of 6 | 6 of 6 |
| Science Inquiry Skills (Unit 4) | 1.7% | 6 of 6 | 6 of 6 |
Marks by dot point
Dot-point numbers and wording are SCSA's own. Where a dot point is written as a list, its items run together here separated by semicolons.
| Dot point | Content | Topic | Share of marks | Papers |
|---|---|---|---|---|
| 4.6.1 | humans as primates are classified as great apes. The species within the great ape family are differentiated by DNA nucleotide sequences, which brings about differences in relative size of cerebral cortex; mobility of the digits; stance and locomotion – adaptations to bipedalism, brachiation and quadrupedalism; prognathism and dentition | Hominid evolutionary trends | 6.8% | 6 of 6 |
| 3.4.5 | transmission of nerve impulses is via electro-chemical changes that occur at the generation of the impulse, the propagation of the impulse along the nerve fibre, and the transfer of the impulse across the synapse | Central and peripheral nervous system | 4.9% | 6 of 6 |
| 4.3.1 | mutations in genes and chromosomes can result from errors in DNA replication, cell division or from damage caused by mutagens | Mutations | 4.2% | 6 of 6 |
| 4.5.4 | both relative dating techniques, including stratigraphy and index fossils, and absolute dating techniques, including radiocarbon dating and potassium-argon dating, have limitations of application | Evidence for evolution | 4.1% | 6 of 6 |
| 4.6.2 | determining relatedness and possible evolutionary pathways for hominins uses evidence from comparisons of modern humans and the other great apes with fossils of Australopithecus afarensis; Australopithecus africanus; Paranthropus robustus; Homo habilis; Homo erectus; Homo neanderthalensis; Homo sapiens | Hominid evolutionary trends | 3.9% | 6 of 6 |
| 4.6.3 | tool use is seen in a number of hominin species and the study of these tools provides important insight into the evolution of the human cognitive abilities and lifestyles. Trends are seen in the changes in manufacturing techniques and the materials used in the tool cultures of Homo habilis; Homo erectus; Homo neanderthalensis; Homo sapiens | Hominid evolutionary trends | 3.6% | 6 of 6 |
| 4.2.1 | developments in biotechnology, for example polymerase chain reaction (PCR), gel electrophoresis and DNA sequencing, have increased access to genetic information of species and provide evidence for evolution (the process of obtaining a DNA sequence is not required) | Science as a Human Endeavour (Unit 4) | 3.4% | 6 of 6 |
| 3.5.3 | blood sugar levels are maintained by controlling of sugar uptake, its storage and release by cells and use in metabolism; these processes involve the hormones of the pancreas and adrenal glands | Homeostasis | 3.2% | 6 of 6 |
| 3.5.2 | thermoregulation occurs by the control of heat exchange and metabolic activity through physiological and behavioural mechanisms | Homeostasis | 3.2% | 4 of 6 |
| 4.2.2 | developments in the fields of comparative biochemistry (including DNA and protein sequences) and bioinformatics have enabled identification of further evidence for evolutionary relationships, which help refine existing models and theories | Science as a Human Endeavour (Unit 4) | 2.9% | 6 of 6 |
| 4.4.2 | gene pools are dynamic, with changes in allele frequency caused by mutations; differing selection pressures; random genetic drift, including the founder effect; changes in gene flow between adjoining groups | Gene pools | 2.9% | 6 of 6 |
| 3.1.4 | represent data in meaningful and useful ways, including the use of mean, median, range and probability; organise and analyse data to identify trends, patterns and relationships; discuss the ways in which measurement error, instrumental accuracy, the nature of the procedure and the sample size may influence limitations in data; and select, synthesise and use evidence to make and justify conclusions | Science Inquiry Skills (Unit 3) | 2.7% | 5 of 6 |
| 3.4.2 | the parts of the central nervous system, including the brain (cerebrum, cerebellum, medulla oblongata, hypothalamus, corpus callosum) and spinal cord, have specific roles in the co-ordination of body functions and are protected by the bones of the skull, the meninges and cerebro-spinal fluid | Central and peripheral nervous system | 2.7% | 6 of 6 |
| 4.5.2 | the fossil record is incomplete and cannot represent the entire biodiversity of a time or a location due to many factors that affect fossil formation, the persistence of fossils and accessibility to fossilised remains | Evidence for evolution | 2.5% | 6 of 6 |
| 3.5.4 | body fluid concentrations are maintained by balancing water and salts via the skin, digestive system and the kidneys, which involve the actions of antidiuretic hormone (ADH) and aldosterone on the nephron, and the thirst reflex | Homeostasis | 2.5% | 6 of 6 |
| 3.6.5 | antiviral and antibiotic drugs are used for treating infections and differ in their specificity to pathogens | Response to infection | 2.4% | 6 of 6 |
| 3.6.7 | immunity is gained through the exposure to specific antigens by the production of antibodies by B lymphocytes and the provision of cell-mediated immunity by T lymphocytes; in both cases memory cells are produced | Response to infection | 2.4% | 6 of 6 |
| 3.3.2 | hormones secreted from the hypothalamus, pituitary, thyroid, parathyroid, pancreas and adrenal glands are involved in homeostasis by affecting specific target organs | Endocrine system | 2.4% | 6 of 6 |
These 18 dot points carry 60.7% of the paper marks between them. Another 37 assessed dot points share the rest, and 3 of the 58 externally assessable dot points have not been assessed in any of these 6 papers. Content that has not appeared is still examinable.
What has moved between papers
Comparing the 2020 to 2022 papers with the 2023 to 2025 papers, two topics have moved by more than 3.0 percentage points.
| Topic | 2020 to 2022 share | 2023 to 2025 share | Movement |
|---|---|---|---|
| Response to infection | 14.3% | 9.8% | down 4.5 points |
| Homeostasis | 10.2% | 13.6% | up 3.4 points |
How the papers are built
Short answer carries 70.6% of the marks across these 6 papers.
| Question type | Share of marks | Marks | Parts |
|---|---|---|---|
| Short answer | 70.6% | 914 | 273 |
| Extended response | 15.5% | 200 | 25 |
| Multiple choice | 13.9% | 180 | 180 |
| Verb | Share of marks | Marks | Parts |
|---|---|---|---|
| explain | 32.2% | 417 | 76 |
| describe | 19.0% | 246 | 46 |
| identify | 13.7% | 177 | 54 |
| outline | 7.8% | 101 | 25 |
| name | 6.7% | 87 | 15 |
| justify | 5.0% | 65 | 19 |
| state | 4.8% | 62 | 31 |
| define | 2.9% | 37 | 8 |
What these percentages do not tell you
Where to practise
Every topic above links to its own page of real SCSA questions with marking criteria and average scores attached: Central and peripheral nervous system, Hominid evolutionary trends, Response to infection, Homeostasis, Evidence for evolution, Gene pools, Science as a Human Endeavour (Unit 4), Endocrine system, Science Inquiry Skills (Unit 3), Mutations, Science as a Human Endeavour (Unit 3) and Science Inquiry Skills (Unit 4). For how students actually score on this content, read WACE Human Biology hardest topics, and for the full question bank start at WACE Human Biology.
Frequently asked questions
Which topic carries the most marks in the WACE Human Biology external exam?
Central and peripheral nervous system carries 14.7% of the marks across the 6 SCSA papers from 2020 to 2025, ahead of Hominid evolutionary trends on 14.3%.
How are marks split between question types in the WACE Human Biology exam?
Short answer carries 70.6% of the marks, extended response carries 15.5% of the marks and multiple choice carries 13.9% of the marks, measured across 6 papers and 1294 marks from 2020 to 2025.
Has the topic balance changed in recent WACE Human Biology papers?
Yes. Response to infection moved down 4.5 percentage points and Homeostasis moved up 3.4 percentage points between the 2020 to 2022 and 2023 to 2025 papers.
How many past papers is this WACE Human Biology analysis based on?
6 SCSA external papers from 2020 to 2025, covering 243 questions and 1294 marks. 0.8% of those marks carry no dot-point mapping and sit outside the percentages.
Sources
- ATAR Human Biology Course Examination, SCSA, 2025. 6 papers, 2020 to 2025, covering 243 questions and 1294 marks. Listed individually in the table at the top of this guide. Dot-point numbering follows the current SCSA Human Biology syllabus.
Syllabus and assessment material referenced in this guide is used under licence, © School Curriculum and Standards Authority. See our SCSA licensing notice. The School Curriculum and Standards Authority does not endorse this publication or product.
Keep reading
Practise what you just read
Work through real SCSA Human Biology questions and get your written answers marked against the official criteria, instantly.