Year 11 - Science
Transfers of biomass between trophic levels
Maintaining biodiversity and human impacts
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
This unit explores trophic levels, biomass pyramids, and the efficiency of biomass transfers in ecosystems. It examines human impacts on biodiversity, factors affecting food security, and biotechnological solutions. Emphasis is on evaluating environmental changes and ethical considerations.
Lesson Summary
You will learn to explain biomass transfer between trophic levels in food chains and calculate the efficiency of biomass transfers.
Key Notes
- All food chains start with a producer that makes the biomass that is transferred to consumers in higher trophic levels.
- Not all biomass from a trophic level is passed to the next one (due to respiration, uneaten parts, egestion, excretion).
- Pyramids of biomass are scaled diagrams that can be used to show the amount of biomass present at each trophic level.
- % efficiency of biomass transfer = (biomass in higher trophic level ÷ biomass in lower trophic level) × 100
- How efficiency of biomass transfer affects the number of organisms in higher trophic levels.
Vocabulary To Learn
- producer: A producer is an organism that makes its own food.
- biomass: Biomass is the mass of living material in one or more organisms.
- trophic level: A trophic level is the position of an organism in a food chain diagram.
- pyramid of biomass: A pyramid of biomass is a diagram which shows the biological mass (biomass) of organisms at each trophic level in a food chain diagram.
- efficiency: The efficiency is how much of something is transferred compared to how much is available, e.g. how much biomass is transferred to a consumer compared to how much is available.
Common Mistakes To Avoid
- A misconception that is often seen is that there is a build up of biomass along a food chain.
3 Quick Questions (With Answers)
1. Explain the scientific idea in this lesson using two key points.
All food chains start with a producer that makes the biomass that is transferred to consumers in higher trophic levels. Not all biomass from a trophic level is passed to the next one (due to respiration, uneaten parts, egestion, excretion).
2. Define this scientific word and use it in context. 'producer'
A producer is an organism that makes its own food. Include the word in a full scientific explanation, not as a single label.
3. Correct this common scientific misunderstanding.
Mistake: A misconception that is often seen is that there is a build up of biomass along a food chain. Correction: The lesson outlines how biomass is actually lost between trophic levels through life processes.
More Lessons In This Unit
- Benefits and challenges of maintaining biodiversity Study Guide
- Climate change and biodiversity: changes in the distribution of organisms Study Guide
- Climate change and biodiversity: forests and oceans Study Guide
- Examples of human interactions with ecosystems, including fish farming Study Guide
- Examples of human interactions with ecosystems, including use of peat Study Guide
- Factors affecting human food security, and possible solutions Study Guide
- Negative human interactions with ecosystems and impacts on biodiversity Study Guide
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