AQA GCSE Combined Science: Trilogy Biology Paper 2 (Foundation), June 2025: Question 2
15 marks · Low Demand difficulty · Short Answer
Answer a series of questions on agriculture, food chains, benefits of insects and hedgerows, peat compost properties, the carbon cycle, and deforestation.
Practise this questionQuestion
Question text
02 Farmers can increase crop yield by controlling the conditions that plants grow in.
02.1 Draw one line from each substance to how the substance increases crop yield.
[2 marks]
02.2 Figure 1 shows a food chain for a farmer’s field.
Figure 1
Which is the secondary consumer in the food chain?
[1 mark]
Tick ( ) one box.
Seeds
Mice
Owls 6
02.3 Bees are insects that live in hives.
The bees fly in and out of the hives.
Figure 2 shows a crop growing in a field.
The farmer has added bee hives to increase the number of bees in the field.
Figure 2
Increasing the number of bees and other insects increases crop yield.
Which are two ways that increasing the number of insects in an area will increase
crop yield?
[2 marks]
Tick ( ) two boxes.
Insects change the soil pH around the crop.
Insects eat leaves from the crop.
Insects eat pests on the crop.
Insects pollinate the crop.
Insects shelter in the crop. 7
02.4 Some farmers increase the size of hedgerows between fields where crops grow.
Suggest one reason why.
[1 mark]
Peat comes from peat bogs.
02.5 Peat can be used to produce garden compost.
Table 1 compares peat compost with a sample of soil.
Table 1
Mineral ion Speed at which water
concentration drains through
Peat compost Low Slow
Soil High Fast
Young plants have short roots.
Explain one advantage of growing young plants in peat compost instead of in soil.
[2 marks]
Peat can also be burnt as fuel.
Figure 3 shows part of the carbon cycle.
Figure 3
02.6 Name process A and process B.
Choose answers from the box.
[2 marks]
condensation photosynthesis respiration transpiration
Process A
Process B 9
02.7 Peat contains carbon compounds.
Explain why burning peat contributes to climate change.
[2 marks]
02.8 Decay is an important process in the carbon cycle.
Which two types of organism cause decay?
[2 marks]
Tick ( ) two boxes.
Algae
Animals
Bacteria
Fungi
Plants
02.9 Deforestation affects the carbon cycle.
Give one use of the land after the land has been cleared by deforestation.
[1 mark]
Mark scheme
Show the mark scheme
Question 2
AO /
Question Answers Mark
Spec. Ref.
02.1 AO1
4.7.1.1
4.7.1.2
4.7.3.2
4.6.2.4
4.7.3.3
do not accept more than one line from a box on the left
AO /
Question Answers Extra information Mark
Spec. Ref.
02.2 owls 1 AO2
4.7.2.1
AO /
Spec. Ref.
02.3 insects eat pests on the crop 1 AO2
4.7.1.1
insects pollinate the crop 1 4.7.2.1
AO /
Spec. Ref.
02.4 any one from: 1 AO2
4.7.3.6
• as a habitat for (beneficial) allow as a shelter / space for 4.7.3.1
insects / animals (beneficial) insects / animals 4.7.1.1
• to keep (larger) animals out allow to protect (the crop) from
or (larger) animals
to keep people out allow to protect (the crop) from 9
people
ignore keep insects / birds out
ignore to protect the crop
unqualified
ignore to stop pests eating the
crop
• (to increase) biodiversity allow to increase the number of
insects / plants
allow descriptions of increasing
biodiversity
• to reduce wind speed allow act as wind break
• as a habitat for predators of ignore to reduce pests
crop damaging organisms unqualified
• to prevent / reduce soil
erosion
ignore so more (crop) can be
grown
AO /
Spec. Ref.
02.5 allow converse if clearly
referring to soil
water takes more time to drain 1 AO3
allow there will be more water
(through) 4.7.3.3
(in the peat compost)
allow water drains / moves
slower
allow water drains / moves
more slowly
ignore water drains slow / slowly
10 (so) water is more likely to be allow (so) there is more time for 1
taken up by plants plants to take up water
or
(so) do not need to water plants allow (so) reduces water use
(as) frequently
or
(which is an advantage
because) young plants cannot
reach water that is deep (in soil /
compost)
ignore references to cost
allow 2 marks for water more
likely to be taken up by plants
before it drains away
AO /
Spec. Ref.
answer line takes precedence
02.6 (A) respiration 1 AO1
4.7.2.2
(B) photosynthesis 1
AO /
Spec. Ref.
02.7 (burning peat) releases / allow (burning peat) releases / 1 AO1
increases carbon dioxide increases CO2 4.7.2.2
ignore burning releases carbon 4.7.3.3
do not accept peat contains 4.7.3.5
carbon dioxide
(which) causes / increases allow (which) is a greenhouse 1
global warming gas
allow (which) causes the 11
greenhouse effect
ignore (which) causes /
increases climate change
AO /
Spec. Ref.
02.8 bacteria 1 AO1
4.7.2.2
4.7.3.3
fungi 1
AO /
Spec. Ref.
02.9 farming (cattle / biofuel / crops / allow examples of farming a 1 AO1
animals) crop / animal 4.7.3.4
allow building
allow named type of building
eg houses / factories
allow mining
allow landfill
allow reforestation / rewilding
12Total Question 2 15
How to answer it
Ecosystems, Agricultural Practices & The Carbon Cycle
What this question tests
This multi-part question tests your core understanding of agricultural biology and ecology topics:
- Crop production methods: The specific roles of chemical fertilisers and herbicides.
- Trophic levels: Identifying producers, primary, and secondary consumers in a food chain.
- Ecosystem interactions: Roles of pollinators, biological pest control, and field hedgerows.
- Data evaluation: Using physical properties of soil and peat compost to explain plant growth advantages.
- The Carbon Cycle: Key processes moving CO₂ (respiration, photosynthesis, combustion, decay) and links to global warming.
Matching Agricultural Substances to Function
AO1 Recall
✅ Correct Matches
- Fertiliser → Adds mineral ions to the soil [1 mark]
- Herbicide → Kills weeds that compete with crops [1 mark]
❌ Common Errors
- Drawing multiple lines: The instruction states "Draw one line from each substance". Drawing two lines from one box loses the mark even if one is correct.
- Confusing herbicide (kills unwanted plants) with pesticide/insecticide (kills pest insects).
Identifying Consumers in a Food Chain
AO2 Application
✅ Correct Answer
Tick: Owls [1 mark]
💡 Key Knowledge
- Seeds: Producer (makes biomass from sunlight).
- Mice: Primary consumer (herbivore eating the producer).
- Owls: Secondary consumer (carnivore eating the primary consumer).
Benefits of Insects in Agriculture
AO2 Application
✅ Correct Answers (Choose 2)
- ☑ Insects eat pests on the crop [1 mark]
- ☑ Insects pollinate the crop [1 mark]
🧠 Exam Technique
Always check whether the option describes an advantage to the farmer. Eating leaves harms the yield, insects do not change soil pH meaningfully, and "shelter in crop" offers no benefit to crop yield.
Reasons for Planting Hedgerows
AO2 Application
✅ Acceptable Answers (Any 1)
- As a habitat / shelter for beneficial insects or birds [1 mark]
- To increase biodiversity [1 mark]
- To act as a windbreak / reduce wind damage [1 mark]
- To prevent or reduce soil erosion [1 mark]
- To keep large animals or people out [1 mark]
❌ Insufficient Answers
- "To protect the crop" is too vague without explaining how (e.g. from wind or large animals).
- "To stop pests eating the crop" is ignored unless you state it provides a habitat for predators of pests.
Comparing Compost Properties for Young Plants
AO3 Analysis & Evaluation
✅ Two-Part Marking Structure
- Observation from table: Water drains through peat compost more slowly / takes more time to drain [1 mark].
- Biological link to young roots: Therefore, water remains available for longer so short roots have more time to absorb it (or roots don't dry out / do not need frequent watering) [1 mark].
🧠 Data Question Rule
When given a table, you must directly use data/descriptors from it. State the property first ("drains slowly"), then explain why this property helps the specific feature in the prompt ("young plants have short roots").
Processes in the Carbon Cycle
AO1 Recall
✅ Correct Identification
- Process A: respiration [1 mark]
- Process B: photosynthesis [1 mark]
💡 Arrow Direction Matters
- Arrow pointing away from organisms to air: CO₂ released → Respiration (or Combustion).
- Arrow pointing from air into plants: CO₂ absorbed → Photosynthesis.
Peat Combustion & Climate Change
AO1 Knowledge Application
✅ Two-Mark Explanation
- Burning peat releases / increases carbon dioxide (CO₂) [1 mark].
- Carbon dioxide is a greenhouse gas, which causes / increases global warming (or enhances the greenhouse effect) [1 mark].
❌ Examiner Warning: Easy Lost Marks
- "Releases carbon": 0 marks! You must specify carbon dioxide or CO₂ .
- "It causes climate change": 0 marks! This repeats the wording already in the question stem. You must specify global warming or the greenhouse effect.
Decomposers & Land Clearance
AO1 Recall
✅ 02.8 Decomposers (Tick 2) [2 marks]
- ☑ Bacteria [1 mark]
- ☑ Fungi [1 mark]
Decomposition of organic material is carried out primarily by microorganisms (bacteria and microscopic fungi).
✅ 02.9 Use of Deforested Land [1 mark]
Any one valid use:
- Farming / Agriculture: Cattle grazing, growing crops (e.g. soy), or growing biofuel crops.
- Building / Urban development: Houses, towns, or factories.
- Quarrying / Mining: Extracting minerals.
Topics
Biology · B7: Ecology
Question and mark scheme from the AQA GCSE Combined Science: Trilogy examination, Biology Paper 2 (Foundation), June 2025. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.