Explain why a community of organisms depends on producers for survival.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
A freshwater pond contains pondweed, water fleas, small fish and pike. The pondweed is the only producer in this ecosystem.
Model answer (4 marks)
Producers carry out photosynthesis, converting light energy into biomass and organic matter.
They are the source of biomass and energy for all other organisms in the food chain.
Primary consumers, such as water fleas, feed on producers and would have no food source without them.
If producers were lost, the whole community would decline or die because of this interdependence.
They are the source of biomass and energy for all other organisms in the food chain.
Primary consumers, such as water fleas, feed on producers and would have no food source without them.
If producers were lost, the whole community would decline or die because of this interdependence.
Examiner tips
- Use the word 'producers' and 'photosynthesis' early. Show the flow of energy from producers to consumers. Mention primary consumers explicitly. Explain the consequence of losing producers.
- common_mistakes
- :
- Confusing producers with consumers. Omitting the role of primary consumers. Failing to link loss of producers to community collapse.
Mark scheme (4 marks)
- Producers carry out photosynthesis / convert light energy into biomass / organic matter
- Producers are the source of biomass / energy for all other organisms in the food chain
- Primary consumers (e.g. water fleas) eat producers and would have no food source without them
- Loss of producers would cause the whole community / all populations to decline or die due to interdependence
Key terms in this question
Related
- Revision notes: Organisation of an ecosystem →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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