Topics · Primary Science · Diversity: Fungi & Bacteria
Fungi and bacteria
Two groups of living things that are neither plants nor animals. Both are useful and both cause harm, and papers ask for one of each — an answer giving only the harm rarely scores full marks.
- 274 exam papers analysed
- appears in 77% of P3 Science papers
- ~3 min read
01 Living things, but not plants
Fungi include mushrooms, moulds and yeast. They are living: they grow, reproduce and need food.
But a fungus cannot make its own food, because it has no chlorophyll and does not photosynthesise. That is the single fact that keeps it out of the plant group, and it is what papers ask.
Bacteria are far smaller — too small to see without a microscope — and are a group of their own again.
Both need warmth, moisture and food to grow, which is why food is kept cold and dry.
02 Useful and harmful — both, always
Questions almost always ask for one of each, so learn them in pairs.
| Group | Useful | Harmful |
|---|---|---|
| Fungi | yeast makes bread rise; moulds give medicines | moulds spoil food; some cause skin disease |
| Bacteria | make yoghurt and cheese; break down dead matter | spoil food; cause illness |
03 Decomposers
Fungi and bacteria break down dead plants and animals, which is the job that makes them matter to the whole environment.
Breaking dead matter down returns nutrients to the soil, where plants take them up again. Without decomposers, dead material would pile up and those nutrients would never be reused.
So a question asking what would happen if all bacteria disappeared wants that answer: dead matter would not decay, and nutrients would not return to the soil.
04 Slowing them down
Food goes bad because fungi and bacteria grow on it. Every method of keeping food takes away one of the three things they need.
- Refrigerating and freezing — removes warmth, so they grow slowly or not at all.
- Drying — removes moisture.
- Salting and adding sugar — draws moisture out.
- Canning and boiling — kills them with heat and then keeps new ones out.
- None of these makes food last for ever. They slow the growth; they do not stop it permanently, which is a distinction papers test.
05 How to say them
These are words most children have never said out loud, and a word you cannot say is a word you avoid using. Capitals mark the syllable you lean on. Tap the speaker to hear it.
- fungussayFUNG-guhsmore than onefungi
A living thing such as a mushroom, mould or yeast that cannot make its own food.
- bacteriasaybak-TEER-ee-uhmore than onebacteria (one is a bacterium)
Living things too small to see without a microscope.
- mouldsaymohldmore than onemoulds
A fungus that grows on food and other damp surfaces.
- yeastsayyeest
A fungus used to make bread rise.
- decomposesaydee-kuhm-POHZ
To break down dead plants and animals, returning nutrients to the soil.
- chlorophyllsayKLOR-uh-fil
The green substance plants use to make food. Fungi have none, which is why they are not plants.
06 What each level is tested on
The same topic, asked differently as it goes up. The percentage is the share of papers at that level in which it appears.
- P3
Recognising fungi and bacteria as living things, and where they are found.
Practise P3 Diversity: Fungi & Bacteria — 10 questions →77% of P3 papers
- P4
Useful and harmful examples, and what they need to grow.
Practise P4 Diversity: Fungi & Bacteria — 10 questions →46% of P4 papers
- P5
Decomposers and their role, and how food is preserved.
Practise P5 Diversity: Fungi & Bacteria — 9 questions →23% of P5 papers
- P6
Fungi and bacteria inside environment questions and fair tests on food spoilage.
Practise P6 Diversity: Fungi & Bacteria — 9 questions →45% of P6 papers
07 Mistakes worth knowing about
Each of these is wrong. Decide why before you open it.
“A mushroom is a plant.”
It cannot make its own food and has no chlorophyll. Fungi are a group of their own.
“Bacteria are always harmful.”
They make yoghurt and cheese and break down dead matter. Questions usually want one useful and one harmful example.
“Freezing kills the bacteria on food.”
It slows them almost to a stop. They can grow again once the food warms up.
“Fungi and bacteria are the same kind of thing.”
Two separate groups. Fungi include mushrooms and moulds you can see; bacteria need a microscope.
“Mould grew on the bread because the bread was old.”
It grew because there was warmth, moisture and food. Age only gives it time.
Now try it
38 questions across 4 levels, marked as you go with the working shown.