Primary 5 · Science · Diversity: Fungi & Bacteria
Diversity: Fungi & Bacteria questions for Primary 5 Science
9 questions to work through online, 2 of them written out the way the paper asks. Answer and you get the working straight away, then a score at the end. No sign-up, and you can retake it as often as you like.
- What decomposers do
- Reasoning without decomposers
- Conditions for decomposers
- Reading results
- Where fungi get food
- Useful and harmful
- Naming the role
- Naming what is returned
- Applying the ideas
| Compost heap | Turned regularly | Kept damp | Months to rot down |
|---|---|---|---|
| J | ✓ | ✓ | 3 |
| K | ✗ | ✓ | 7 |
| L | ✓ | ✗ | 9 |
Answers and explanations for all 9 questions
Every answer with the reasoning behind it. Worth reading after you have tried the set — or on its own, if you are a parent marking it.
What do fungi and bacteria do to a fallen log over many years?
Answer: They break it down and return its materials to the soil.
Decomposers feed on dead material, breaking it apart. The materials it was made of go back into the soil, where plants can use them again.
What would happen in a forest if all its fungi and bacteria disappeared?
Answer: Dead leaves and animals would pile up and the soil would lose its goodness.
Nothing would rot. Dead material would accumulate, and the minerals locked inside it would never return to the soil for plants to use.
The leaves in bin A rotted fastest. Which two statements about the set-ups above are correct?
Answer: A and B only
A beat B, which was dry, and A beat C, which was cold. Each comparison changes one condition, so both moisture and warmth are shown to matter.
Based on the table above, which conclusion is correct?
Answer: Both air and moisture speed up rotting.
J had both and took 3 months. Removing the air took it to 7 and removing the moisture took it to 9, so each condition matters on its own.
How does a fungus growing on a dead tree stump obtain its food?
Answer: It breaks down the dead wood and absorbs the substances released.
A fungus releases substances that break the wood down where it lies, then absorbs what is released. That is why the stump crumbles.
Which two of these are examples of bacteria or fungi being useful?
Answer: A and B only
The same organisms are useful or harmful depending on where they act. Breaking food down is welcome in a compost heap or a yoghurt pot and unwelcome in the meat drawer.
Fungi and bacteria that feed on dead plants and animals and return their materials to the soil have a special name. What are they called?
Answer: decomposers
Organisms that break down dead material are decomposers.
When decomposers break down a dead leaf, they return substances the plant took from the ground. What do they return the leaf's materials to?
Answer: soil
Decomposers return the materials to the soil, where plants can take them up again.
Why do gardeners add compost to their soil rather than throwing plant waste away?
Answer: Decomposers have already released the plants' minerals into it, ready for new plants to use.
Composting is decomposition put to work. The minerals locked in last year's plants are released and go straight back into the bed for this year's.