Primary 4 · Science · Diversity: Fungi & Bacteria
Diversity: Fungi & Bacteria questions for Primary 4 Science
10 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.
- Choosing the right comparison
- Reading results
- Keeping food
- Useful microbes
- Why fungi are not plants
- Fair testing microbes
- How fungi feed
- Naming a condition
- Naming a method
- Reasoning about spoilage
| Set-up | Damp | Warm | Mould after 5 days |
|---|---|---|---|
| A | ✓ | ✓ | ✓ |
| B | ✗ | ✓ | ✗ |
| C | ✓ | ✗ | ✗ |
| D | ✗ | ✗ | ✗ |
Answers and explanations for all 10 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.
Which two set-ups shown above should be compared to find out whether warmth affects mould growth?
Answer: A and C
To test warmth, everything but the temperature must match. A and C are both damp and differ only in being in a warm room or a fridge.
Based on the table above, what do fungi need in order to grow well?
Answer: both moisture and warmth together
Only A, which had both, grew mould. Take away either condition and nothing grows, so both are needed together.
Which two of these keep food fresh by making conditions harder for bacteria and fungi?
Answer: A and B only
Cooling and drying each remove one of the conditions microbes need. Warmth and moisture do the opposite.
Which of these depends on bacteria doing their work?
Answer: turning milk into yoghurt
Yoghurt is made by adding particular bacteria to milk on purpose and letting them work. The others are all attempts to stop microbes.
A pupil wrote 'mushrooms are plants because they grow in soil'. What is wrong with the reasoning?
Answer: Where something grows does not decide its group; mushrooms cannot make their own food.
Groups are decided by characteristics, not by location. A plant makes its own food using light; a mushroom cannot, so it is a fungus.
A class tests whether sugar makes bread mould faster. Which two things must they keep the same?
Answer: A and B only
Only the sugar should differ. Same-sized slices in the same place mean any difference in mould must be down to the sugar.
Bread mould spreads across a slice of bread over several days. Where is it getting its food?
Answer: from the bread it is growing on
A fungus feeds on whatever it grows on. The mould is breaking the bread down and taking its food from it, which is why the bread spoils.
A slice of bread kept in a fridge grows no mould, while an identical slice in a warm kitchen does. Which condition does the mould need that the fridge takes away?
Answer: warmth
The fridge removes the warmth the mould needs, which is why the cold slice stays clean.
Fish is left in the sun until all the water has gone, so that it can be stored for months. What is this method of preserving food called?
Answer: drying
Removing the water so microbes cannot grow is drying.
Why does an opened carton of milk go sour in a day on the table but last a week in the fridge?
Answer: The cold slows the bacteria down so they multiply far more slowly.
The bacteria are present either way. Warmth lets them multiply quickly; cold slows them down, so the same milk takes far longer to sour.