Health and Disease resources
Biology, grade 9. Notes, worksheets, videos, interactive tools and revision materials for this chapter.
Notes
Study notes
The chapter's lessons are the notes — read them in order, then use the resources below.
01Meet the PathogensMeet bacteria, viruses, fungi and protists and find out how they make us ill.Read lesson →02The Body's DefencesDiscover skin, stomach acid, white blood cells and antibodies that fight infection.Read lesson →03How Vaccines WorkLearn how vaccination trains the immune system to defeat a disease before it strikes.Read lesson →04A Healthy LifestyleExplore how diet, exercise, sleep and avoiding smoking protect long-term health.Read lesson →
Worksheets
Practice worksheet
Attempt every question before revealing the answer — that struggle is where learning happens.
Practice questions live inside each lesson — work through them there, then return for revision.
Videos
Watch and learn
Hand-picked searches to find a clear video explanation of each lesson.
Revision
Revision checklist
Can you explain each of these out loud, without looking? If not, re-read that lesson.
- Meet the Pathogens: Meet bacteria, viruses, fungi and protists and find out how they make us ill.
- The Body's Defences: Discover skin, stomach acid, white blood cells and antibodies that fight infection.
- How Vaccines Work: Learn how vaccination trains the immune system to defeat a disease before it strikes.
- A Healthy Lifestyle: Explore how diet, exercise, sleep and avoiding smoking protect long-term health.
- Read each lesson's summary and re-do its practice questions from memory.