AQA · GCSE · Biology
Course version: 8461 · Version from Sept 2018
All food chains begin with a producer which synthesises molecules.
Full specification wording
Levels of organisation: All food chains begin with a producer which synthesises molecules.
A producer is an organism that makes its own organic nutrients, usually by photosynthesis.
Checked against the AQA 8461 specification (opens in a new tab) on .
- Point 3 of 12
- 4 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
A producer is an organism that makes its own organic nutrients, usually by photosynthesis. Producers synthesise molecules such as glucose from carbon dioxide and water using light energy, and they build these molecules into carbohydrates, proteins and lipids that form their biomass. Because producers do not need to eat other organisms to obtain carbon, they occupy the first trophic level of every food chain. Consumers obtain their carbon and energy by eating producers or other consumers, so all food chains depend on the molecules synthesised by producers. In a few ecosystems, chemosynthetic bacteria act as producers, but the principle is the same: the first organism in the chain makes its own organic molecules.
What earns the marks
- A producer is an organism that synthesises its own organic molecules, usually by photosynthesis.
- Producers use carbon dioxide, water and light energy to make glucose and other biological molecules.
- Producers occupy the first trophic level of a food chain.
- Consumers depend on the molecules made by producers because they cannot make their own organic nutrients in the same way.
- Some producers, such as chemosynthetic bacteria, synthesise molecules without light, but they still form the base of their food chain.
Common mistakes and how to put them right
Thinking the producer is always the largest organism.
Put it right: Producers are defined by how they obtain nutrients, not by size.
Saying producers take in food from the soil.
Put it right: Producers synthesise organic molecules, although they do absorb water and mineral ions from the soil.
Forgetting that the arrow from a producer points to the consumer that eats it.
Put it right: The arrow shows the direction of energy transfer, from producer to consumer.
Exam tips
- Name the producer in a given food chain and state that it synthesises molecules by photosynthesis.
- Use the phrase 'first trophic level' when identifying the position of the producer.
- If a food chain is shown, check that it starts with a producer before describing the consumers.
Try the lesson
The start of the Levels of organisation: All food chains begin with a producer which synthesises molecules. lesson, made from checked teaching notes for this specification point.
Have a go first
Which type of organism always forms the first stage of a food chain?
Listen
A producer is an organism that makes its own organic nutrients, usually by photosynthesis. Producers synthesise molecules such as glucose from carbon dioxide and water using light energy, and they build these molecules into carbohydrates, proteins and lipids that form their biomass. Because producers do not need to eat other organisms to obtain carbon, they occupy the first trophic level of every food chain. Consumers obtain their carbon and energy by eating producers or other consumers, so all food chains depend on the molecules synthesised by producers. In a few ecosystems, chemosynthetic bacteria act as producers, but the principle is the same: the first organism in the chain makes its own organic molecules. A strong answer earns marks for these points. A producer is an organism that synthesises its own organic molecules, usually by photosynthesis. Producers use carbon dioxide, water and light energy to make glucose and other biological molecules. Producers occupy the first trophic level of a food chain. Consumers depend on the molecules made by producers because they cannot make their own organic nutrients in the same way. A common slip: Thinking the producer is always the largest organism. Instead, producers are defined by how they obtain nutrients, not by size. Exam tip: Name the producer in a given food chain and state that it synthesises molecules by photosynthesis.
See it
Key words
Say what each word means before you turn the card.
Producer
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Photosynthesis
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First trophic level
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Consumers
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See every definition
- Producer
- An organism that makes its own organic nutrients, usually by photosynthesis, and synthesises molecules such as glucose.
- Photosynthesis
- The process by which producers synthesise molecules such as glucose from carbon dioxide and water using light energy.
- First trophic level
- The position occupied by producers in every food chain because they do not need to eat other organisms to obtain carbon.
- Consumers
- Organisms that obtain their carbon and energy by eating producers or other consumers, so all food chains depend on the molecules synthesised by producers.
Label the diagram
Some boxes have lost their names. Pick the right name for each number.
1Box 1
2Box 2
3Box 3
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