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Science · Year 9 · Unit 1

Disease

This 22-lesson unit explores how the body keeps itself stable, what disease is, how it spreads, and how the body fights back. You will investigate homeostasis, pathogens, the immune system, vaccination, antibiotics, and the science behind public health decisions that affect millions of lives.

22lessons

5assessments

9-13hstudy

Start Lesson 1 →

Lessons

Block A, Foundations of Disease (Lessons 1-6)

What Is Disease?

Defining health, disease, and disorder; infectious vs non-infectious

Stable Internal Conditions

Homeostasis; the internal environment; why stability keeps us healthy

System Interactions and Feedback

Negative feedback; nervous vs endocrine control of the body

Types of Pathogens

Bacteria, viruses, fungi, protists, parasitic worms; how pathogens cause harm

How Disease Spreads

Transmission routes: direct, indirect, airborne, vector-borne, waterborne

First Line of Defence

Physical and chemical barriers; skin, mucous membranes, stomach acid

Cumulative assessment for Lessons 1-6

Block B, The Immune System (Lessons 7-11)

Infection and Defence: Review and Connect

Consolidating infection, transmission, and the early lines of defence

Second Line of Defence

Inflammation, phagocytes, fever, complement proteins

The Immune Response: Review and Connect

Lines of defence, adaptive immunity, B cells, T cells, immune memory

Vaccination and Immunity

Active vs passive immunity; how vaccines train the immune system

Australia's Immunisation Story

National Immunisation Program; historical outbreaks; immunisation data

Cumulative assessment for Lessons 7-11

Block C, Fighting Disease with Science (Lessons 12-16)

Herd Immunity and Vaccination Coverage

Herd immunity threshold; R0; protecting the vulnerable

Antibiotics and Antivirals

How antibiotics and antivirals work; proper use; antimicrobial resistance

Designing a Disease Investigation

Investigable questions; variables; fair tests; validity

Non-Infectious Disease

Lifestyle diseases (CVD, diabetes, obesity); risk factors; prevention

Investigating Outbreaks: Epidemiology

Outbreak tracing; contact tracing; incidence and case data

Cumulative assessment for Lessons 12-16

Block D, Disease in Context (Lessons 17-22)

Cancer: When Cells Go Wrong

Mutations; benign vs malignant tumours; metastasis; screening

Aboriginal and Torres Strait Islander Health

Traditional plant medicine; historical health impacts; Closing the Gap

Global Disease and Pandemics

Pandemic vs epidemic; COVID-19; influenza; malaria; global response

Investigating Disease

Designing fair tests; case-control studies; data analysis; ethics

Public Health and Prevention

Sanitation, quarantine, screening, health promotion; Australian systems

Unit Synthesis and Depth Study Prep

Connecting concepts; preparing investigable questions; planning studies

Cumulative assessment for Lessons 17-22

Full unit assessment covering all 22 lessons

Unit Snapshot

22lessons

4checkpoints

1unit quiz

1NESA outcome

Ready to start?

Work through the lessons in order, each one builds on the last.

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