How Your Body Fights Germs

Science · The Human Body · ages 9-11

Name ______________________ Date ____________

What do white blood cells do when they find a germ inside your body?
- They ignore it
- They destroy it
- They turn into skin
What is the first thing that stops germs from getting into your body?
- Your skin
- Your blood
- Your bones
Vaccines contain a weakened or inactive form of a germ.
Circle one: True False
A germ manages to get past a cut in the skin. What happens next inside the body?
- White blood cells find and destroy it
- The skin grows back instantly
- Nothing happens until a vaccine is given
Tom gets a small cut while playing outside. Which part of his immune system was the first to try to stop germs from entering?
- His white blood cells
- His vaccine
- His skin
Why does a vaccine help protect you from a disease you have never had?
- It replaces your skin with a stronger layer
- It trains white blood cells to recognise the germ ahead of time
- It removes all germs from your body forever
If your body has never been vaccinated against a disease, your white blood cells cannot fight that disease at all.
Circle one: True False
Priya says: 'Since my skin covers my whole body, germs can never get inside me.' What is wrong with her idea?
- Skin actually invites germs in
- White blood cells only work after a vaccine
- Germs can enter through cuts, the nose, or the mouth

Answer key

For grown-ups. Fold this page away before handing over the rest.

They destroy it · White blood cells attack and destroy bacteria and viruses they find.
Your skin · Your skin covers your body and blocks most germs from getting inside.
True · That weak or inactive germ is safe, but it still teaches your immune system to recognise the real disease.
White blood cells find and destroy it · Once germs are inside, white blood cells travel through the blood to find and fight them.
His skin · The skin is the body's first barrier. Once it's broken, germs can get in more easily.
It trains white blood cells to recognise the germ ahead of time · The immune system learns to recognise the weakened germ, so it can react fast if the real disease ever appears.
False · White blood cells can still fight unfamiliar germs, but a vaccine helps them recognise and respond much faster.
Germs can enter through cuts, the nose, or the mouth · Skin is a strong barrier, but it is not the only way in. Germs can enter through breaks in the skin or through openings like the nose and mouth.