Teacher sheet · Ages 10–11 · about 45–50 minutes
How the body fights germs
Lesson page: echoesof.science/school/immune-system/ages-10-11/ · Pupil worksheet: echoesof.science/school/immune-system/ages-10-11/print/
Learning aims
- Describe barriers, the innate response and the adaptive response.
- Know that antibodies are made by B cells and that memory cells give faster protection.
- Explain how germs spread and why handwashing helps.
Lesson plan
| Time | Activity |
|---|---|
| 5 min | Starter: list all the ways a germ could get into your body. |
| 10 min | Read the text; draw the three lines of defence. |
| 20 min | Germ-spreading experiment and chart. |
| 5 min | Game: Barrier, fast or targeted? |
| 5 min | Quiz. |
Materials for the experiment
- Hand cream
- Fine biodegradable glitter
- Everyday objects: a pencil, a door handle model, a ball
- Magnifying glasses
- Soap, water and paper towels
- Tally chart
Safety: Use biodegradable glitter; keep hands away from eyes and mouths during the activity. Check for skin allergies to the cream. Wash and dry hands at the end and wipe objects clean.
Common misconceptions
| Pupils may think… | Actually… |
|---|---|
| Antibodies are white blood cells. | Antibodies are proteins made by B cells (plasma cells). |
| The immune system only works when you are ill. | Barriers work all the time and white blood cells constantly patrol the blood. |
| Inflammation means something has gone wrong. | Redness, swelling and warmth are normal signs of the innate response working. |
Worksheet answers
- Any three of: skin, mucus, tears, saliva, stomach acid.
- The innate response is fast and attacks any germ (for example by engulfing it); the adaptive response is slower but targets one particular germ with antibodies and T cells, and leaves memory cells.
- Glitter passed from hand to hand and onto objects, getting less each time; soap and water removed most of it.
- The first time, the adaptive response takes days to build up; the second time, memory cells respond much faster.
Quiz answers
- Where do all immune cells start? In the bone marrow. Immune cells come from precursors in the bone marrow.[1]
- Which is a barrier that stops germs getting in? Skin. Skin resists the entry of germs.[2]
- What do macrophages do? Engulf and digest germs. Macrophages are white blood cells that engulf pathogens.[2]
- Antibodies are made by… B cells. B cells (as plasma cells) make antibodies.[4]
- Why do memory cells help? They respond faster if the same germ returns. Memory cells make the second response quicker.[4]
- Redness, swelling, heat and pain around a cut are signs of… inflammation. Inflammation is part of the innate response.[2]
Going further
Find out what the thymus, lymph nodes and spleen do, and mark them on an outline of the body.
Sources used in this lesson
- [1] Overview of the Immune System (National Institute of Allergy and Infectious Diseases (NIH, USA)): reliability High
- [2] Concepts of Biology, 17.2 Innate Immunity (OpenStax, Rice University): reliability High
- [4] Concepts of Biology, 17.3 Adaptive Immunity (OpenStax, Rice University): reliability High
- [6] About Handwashing (Centers for Disease Control and Prevention (USA)): reliability High
- [7] Hand Hygiene Frequently Asked Questions (Centers for Disease Control and Prevention (USA)): reliability High
Full list with links and a note on each source's reliability: echoesof.science/school/immune-system/sources/
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