Trophic levels: GCSE Biology
Producers and consumers, pyramids of biomass, transfer of biomass and efficiency
The short version
Trophic levels feed pyramids of biomass; roughly 10% of biomass is transferred, the rest is lost as waste and heat.
Key idea
Grade 2–3: The plant is at the bottom of the feeding list. Meat-eaters are higher up.
Grade 5–6: I can number 1 to 4 and use producer/consumer words.
Grade 9: I never reverse the arrows (they are not "who is scared"). I can say a food web has organisms in more than one level.
Go a bit deeper
Draw bars centred, producer at the bottom, labelled. Do not sketch a triangle and hope. If they give numbers, the widths must match the scale.
Grade 2–3: There is more plant-stuff than rabbit-stuff than fox-stuff.
Grade 5–6: I can draw a four-level pyramid with producer at the bottom.
Worked example
Worked example
Grade 2–3: The plant is at the bottom of the feeding list. Meat-eaters are higher up. Grade 5–6: I can number 1 to 4 and use producer/consumer words. Grade 9: I never reverse the arrows (they are not "who is scared"). I can say a food web has organisms in more than one level.
Lessons in this topic
- Trophic levels
- Pyramids of biomass
- Transfer of biomass
- Efficiency calculations
- Food production and efficiency
In the app each lesson is video (when we have a real YouTube id) then intro, learn and summary steps.
What the examiner wants
Construct or interpret biomass pyramids, calculate efficiency of transfer, and explain why eating plants feeds more people.
Try these questions
Cover the answers and have a go first. Worked solutions are underneath.
Trophic level 1 is always the
In grass → slug → thrush, the thrush is a
A pyramid of biomass is usually drawn using
Pyramids of numbers can invert because
Common mistakes
- Trophic level 1 is never the predator. If you start the chain with a fox you have already lost the pyramid.
- A pyramid of numbers is not a pyramid of biomass. One tree can feed thousands of insects - numbers invert; biomass usually does not.
- Do not write "energy disappears". Lost from the food chain means transferred to the environment, mostly as heat.
- Do not invert the fraction (taken in / transferred). That gives over 100% and is obviously wrong.
Answers and working
Frequently asked questions
Is GCSE Trophic levels on Combined Science and Triple?
Trophic levels is Triple-only Biology. Combined Science students can skip it.
Which exam board is this Trophic levels page for?
The ideas are board-agnostic for AQA, Edexcel, OCR, WJEC and CCEA. Paper lengths and question numbers differ — check your specification.
Is Trophic levels Foundation or Higher?
The core ideas appear on both tiers. Higher papers add extra application and some HT-only detail, marked in lessons with a Higher badge.
Learn, try, get feedback, fix the mistake
Open the stepped lesson, then the quiz with hints. Required-practical and calculation questions use the same method you will need in the paper.
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