They are on your skin, in the soil and in every breath — living things too small to see without a microscope. Most microorganisms are harmless or helpful, and a few cause illness. At Microbe Marsh, Year 5 scientists meet bacteria, viruses and fungi.
What your child will learn
- Know that microorganisms are living things too small to see
- Name three kinds: bacteria, viruses and fungi
- Give examples of helpful and harmful microbes
- Explain how hand-washing and vaccines protect us
Helpful microbes
Yeast is a fungus that makes bread rise. Bacteria turn milk into yoghurt and cheese. In soil, microbes rot dead leaves and return their goodness to the earth, and bacteria in our gut help us digest food.
Harmful microbes
Some microbes, often called germs, cause illnesses such as colds, flu and food poisoning, and others make food go mouldy. Washing hands with soap, cooking and chilling food properly, and vaccines all help to stop them.
Example questions
Here are a few questions like the ones in the first quest. Can you solve them?
1. True or false? All microorganisms are harmful.
Show answer
Answer: False. Many are helpful — they make bread, yoghurt and healthy soil.
2. Which microorganism makes bread rise?
🍞- Rust
- Mould
- Yeast
- A virus
Show answer
Answer: Yeast. Yeast makes gas bubbles that puff up the dough.
3. Which of these is a microorganism?
- Bacteria
- A grain of sand
- A daisy
- An ant
Show answer
Answer: Bacteria. Bacteria are living things far too small to see.
Tips for grown-ups
- Mix yeast, sugar and warm water in a bottle with a balloon over the top and watch it inflate.
- Seal a slice of bread in a bag and watch mould grow over a week — don’t open it.
- Put glitter on your hands to see how easily “germs” spread, then wash it off.