Trophic Levels

This lesson covers:

  1. The idea that trophic levels are just the different levels of a food chain
  2. The names of each trophic level e.g. 'producers', 'primary consumers' etc.
  3. The difference between 'herbivores', 'carnivores', and 'omnivores' 
  4. How detritivores break down dead organic matter and recycle nutrients 

What term is used for the stages in a food chain?

Trophic steps

Trophic levels

Feeding levels

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Diagram showing trophic levels with an owl at the top, followed by a snake, rabbits, and grass.

What is the name used to refer to the trophic level highlighted in the diagram above?

Producers 

Primary consumer 

Apex predator

Secondary consumer 

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Diagram showing trophic levels with a hawk, snake, rabbits, and grass.

What is the name used to refer to the trophic level highlighted in the diagram above?

Producers 

Secondary consumer 

Apex predator

Primary consumer 

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Diagram showing trophic levels with a hawk at the top, followed by a snake, rabbits, and grass.

What is the name used to refer to the trophic level highlighted in the diagram above?

Producers 

Secondary consumer 

Primary consumer 

Apex predator

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Which trophic level contains secondary consumers?

Trophic level 1

Trophic level 2

Trophic level 3

Trophic level 4

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What do the arrows in a food chain show?

The transfer of energy & biomass

Which organisms are dependent on which 

How many organisms are at each trophic level

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What is an omnivore?

An organism which eats both plants and animals

An organism which eats only plants 

An organism which eats only animals

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What is a herbivore?

An organism which eats both plants and animals

An organism which eats only animals

An organism which eats only plants 

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What is a carnivore?

An organism which eats only plants 

An organism which eats only animals

An organism which eats both plants and animals

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What must be true of a primary consumer?

It eats secondary consumers

It eats plants or algae

It eats meat and plants

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Why are food chains usually no longer than five or six trophic levels?

There are fewer prey than predators

The predators would have to be too large 

Only ~10% of the energy and biomass is transferred between each level

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What is a decomposer?

An organism that produces biomass using photosynthesis 

An organism that breaks down dead organisms 

An animal that is fed on by other animals 

An animal that feeds on other animals 

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Illustration showing decomposers including bacteria, fungi, and a cow eating grass.

Which of the following are often decomposers?

(Select all that apply)

Plants 

Animals

Fungi

Bacteria

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Small animals like worms and woodlice that help to break down organic matter into smaller pieces are known as: 

Predators 

Detritivores 

Producers 

Herbivores 

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