AQA GCSE Biology Biology Paper 2 (Foundation), June 2023: Question 3
13 marks · Low Demand difficulty · Short Answer
Examine feeding relationships, adaptations, predator-prey population dynamics, and biomass loss in a food chain consisting of grass, snowshoe hare, and lynx.
Practise this questionQuestion
Question text
03 Different species in a habitat may depend on each other for food.
Figure 3 shows a food chain.
Figure 3
03.1 The grass needs energy to grow.
What is the source of energy for the grass?
[1 mark]
03.2 Table 2 lists different types of feeding relationship.
Table 2
Feeding relationship Organism
Secondary consumer Lynx
Primary consumer
Producer
Herbivore
Carnivore
Prey
Predator
Write the name of one organism from Figure 3 in each box in Table 2.
[3 marks]
Each organism may be written in one box or in more than one box.
The first box has been completed for you.
03.3 Figure 4 shows the appearance of the snowshoe hare in the summer and in
the winter.
Figure 4
Snowshoe hare in summer Snowshoe hare in winter
The snowshoe hare has a different fur colour in the summer than in the winter.
Explain how the different fur colour increases the chance of survival of the
snowshoe hare.
[3 marks]
Figure 5 shows how the number of snowshoe hares and the number of lynx varied in
one area between 1900 and 1935.
Figure 5
03.4 Figure 5 shows that the number of snowshoe hares and the number of lynx increase
and decrease several times.
Suggest two reasons why the number of snowshoe hares increases.
[2 marks]
03.5 The number of snowshoe hares increased and decreased four times between 1900
and 1935.
What effect does an increase in the number of snowshoe hares have on the number
of lynx?
[1 mark]
03.6 Suggest one reason why the number of lynx decreased from 1915 to 1919.
Use information from Figure 5.
[1 mark]
03.7 When the snowshoe hare eats grass, about 90% of the biomass of the grass is lost.
Give two ways the biomass is lost.
[2 marks]
Mark scheme
Show the mark scheme
Question 3
AO /
Question Answers Extra information Mark
Spec Ref.
03.1 any one from: ignore photosynthesis 1 AO1
4.7.2.1
• sun 4.7.4.3
• light
AO /
Question Answers Mark
Spec Ref.
03.2 AO3
Feeding relationship Organism 4.7.2.1
4.7.4.1
Secondary consumer lynx
Primary consumer (snowshoe) hare
Producer grass
Herbivore (snowshoe) hare
Carnivore lynx 1
Prey (snowshoe) hare
Predator lynx 1
if no other mark awarded allow 1 mark for 3 correct answers
AO /
Spec Ref.
03.3 camouflaged / hidden allow description eg blends in 1 AO3
or not (easily) seen with surroundings
from lynx / predator / carnivore 1 AO2
not killed / eaten allow less likely to be killed / 1 AO2
eaten
4.7.1.2
4.7.1.3
4.7.1.4
4.7.2.1
AO /
Spec Ref.
03.4 any two from: 2 AO2
• fewer lynx (to eat them) allow not many predators / lynx 4.7.1.3
do not accept no lynx / 4.7.2.1
predators
• more food / grass (available) allow a lot of food / grass 11
• hares reproduce / breed /
multiply
AO /
Spec Ref.
03.5 (number of lynx) increases 1 AO3
4.7.1.3
4.7.2.1
AO /
Spec Ref.
03.6 less food or fewer (snowshoe) ignore the lynx were hunted 1 AO2
hares (to eat) or fewer prey 4.7.1.3
4.7.2.1
do not accept no food
AO /
Spec Ref.
03.7 any two from: 2 AO1
• (lost in) respiration (of allow as carbon dioxide 4.7.2.1
4.7.4.3
snowshoe hare)
• egestion / faeces allow not all digested
• excretion / urea / urine
• not all eaten allow not all (named) parts
eaten
if no other mark awarded, allow
1 mark for waste
Total Question 3 13
How to answer it
Feeding Relationships, Predator-Prey Cycles & Biomass Transfer
This question assesses core ecology concepts from AQA GCSE Biology Specification sections 4.7.1, 4.7.2, and 4.7.4:
- Energy source in ecosystems: Identifying light / the Sun as the primary energy input.
- Trophic levels & feeding terms: Correctly identifying producers, primary/secondary consumers, herbivores, carnivores, predators, and prey.
- Structural adaptations: Explaining how camouflage increases survival chances against predation.
- Predator-prey population cycles: Interpreting population graphs and explaining reasons for population increases and crashes.
- Biomass loss: Recalling the specific biological pathways by which energy and biomass are lost between trophic levels.
Question 03.1
Source of Energy for Producers [1 mark]
✅ Correct Answer
Any one from:
- Light
- Sun (or sunlight)
❌ Common Errors & Trap
Do NOT write "photosynthesis". Photosynthesis is the process that transfers energy, not the source of the energy itself. Writing photosynthesis scores 0 marks.
Question 03.2
Feeding Relationships Terminology [3 marks]
| Feeding Relationship | Correct Organism | Examiner Marking Pair |
|---|---|---|
| Secondary consumer | Lynx (Given in paper) | — |
| Primary consumer | (Snowshoe) hare | Both correct = 1 mark |
| Producer | Grass | |
| Herbivore | (Snowshoe) hare | Both correct = 1 mark |
| Carnivore | Lynx | |
| Prey | (Snowshoe) hare | Both correct = 1 mark |
| Predator | Lynx |
💡 Key Definitions to Remember
- Producer: Photosynthetic organism that synthesises its own food (grass).
- Herbivore: Animal that eats only plants (snowshoe hare).
- Carnivore: Animal that eats other animals (lynx).
- Prey: Organism hunted and eaten by a predator (snowshoe hare).
🧠 Exam Technique
Notice that organisms can be used more than once. There are 6 blanks grouped into 3 pairs (1 mark per correct pair). If you don't get full marks on the pairs, a compensatory 1 mark is awarded if any 3 answers are correct.
Question 03.3
Adaptation and Survival (Camouflage) [3 marks]
✅ 3-Step Marking Points
- The hare is camouflaged / hidden (or blends in with surroundings / snow in winter and vegetation in summer).
- Hidden from predators / lynx / carnivores.
- Therefore it is less likely to be killed / eaten.
🧠 Exam Technique: "Explain Survival"
Whenever an exam asks how an adaptation increases survival, always provide the 3-link chain:
Physical feature (camouflaged/blends in) → Interaction (unseen by predator) → Outcome (not killed/eaten → survives).
Question 03.4
Reasons for Hare Population Increase [2 marks]
✅ Correct Reasons (Any TWO)
- Fewer lynx / fewer predators (to hunt or eat them).
- More food / grass available.
- Hares reproduce / breed / multiply.
❌ Common Misconceptions
- "No lynx / no predators": Reject! In nature, predator numbers fall, but they never drop to absolute zero. Always say fewer, not none.
- Do not just describe the graph (e.g. "it goes up"). The question asks you to suggest reasons why.
Question 03.5
Effect of Prey Increase on Predator Population [1 mark]
✅ Correct Answer
The number of lynx increases.
💡 The Predator-Prey Lag
More prey means more food for the predator. Lynx survive longer, reproduce more successfully, and their numbers rise shortly after the hare population rises.
Question 03.6
Interpreting Population Drop (1915–1919) [1 mark]
✅ Correct Answer
Any one from:
- Less food / less prey.
- Fewer (snowshoe) hares to eat.
❌ Common Errors
- "Hunting / disease": The question specifically demands: "Use information from Figure 5". You must refer directly to the data shown (the hare population dropped just before/during this period).
- "No food": Do not state there is "no food"; write less food or fewer hares.
Question 03.7
Loss of Biomass Between Trophic Levels [2 marks]
✅ Accepted Biological Reasons (Any TWO)
- Respiration: Lost as carbon dioxide (CO₂) and water during cellular respiration to release energy.
- Egestion / faeces: Undigested food that passes out of the body.
- Excretion / urine: Metabolic waste, such as urea in urine.
- Not all eaten: Some parts of the grass (e.g. roots) are not consumed by the hare.
❌ Examiner Pitfalls
- "Lost as heat": Respiration releases energy; some is transferred thermally, but state respiration or loss of CO₂ to guarantee the mark.
- Egestion vs. Excretion: Know the difference! Faeces is egestion (undigested material); urine is excretion (metabolic waste). Stating either is acceptable, but be biologically precise.
- If no full points are awarded, writing simply "waste" only gets a maximum of 1 mark.
Topics
Biology · B7: Ecology
Question and mark scheme from the AQA GCSE Biology examination, Biology Paper 2 (Foundation), June 2023. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.