New
New
Year 8

Pyramids of number

I can create and interpret pyramids of number to show the size of a population at each trophic level.

New
New
Year 8

Pyramids of number

I can create and interpret pyramids of number to show the size of a population at each trophic level.

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Lesson details

Key learning points

  1. Food chains show the feeding relationships between organisms and the flow of energy through a habitat.
  2. The number of organisms at each trophic level in a food chain can be used to create a pyramid of number.
  3. Pyramids of number use scaled bars to represent the number of organisms.
  4. Pyramids of number have the producer at the bottom.

Common misconception

Pupils often think that the size of organisms has to increase at each trophic level within a food chain diagram.

The lesson addresses the misconception through exemplification. There is coverage of inverted pyramid of number to show that some producers are larger organisms that are eaten by smaller organisms.

Keywords

  • Trophic level - A trophic level is the position of an organism in a food chain diagram.

  • Pyramid of number - A pyramid of number is a diagram which shows the total number of organisms at each trophic level in a food chain diagram.

  • Herbivore - An animal that only eats plants (producers) is called a herbivore.

  • Carnivore - An animal that eats other animals (consumers) is called a carnivore.

  • Omnivore - An animal that eats both plants (producers) and other animals (consumers) is called an omnivore.

Pupils can be given populations of organisms within a food chain diagram and use the information to draw pyramid of number diagrams for themselves.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Which organism is the producer in this food chain?
An image in a quiz
Correct answer: cabbage
greenfly
ladybird
Q2.
Where do producers get their energy from?
Correct Answer: The Sun, Sun, the sun
Q3.
Match the word to its description.
Correct Answer:herbivore,organisms who only eat plant material

organisms who only eat plant material

Correct Answer:carnivore,organisms that consume other animals

organisms that consume other animals

Correct Answer:omnivore,organisms that eat both plant and animal material

organisms that eat both plant and animal material

Q4.
Match the word to its description.
Correct Answer:predator,animals that hunt and eat what they catch

animals that hunt and eat what they catch

Correct Answer:prey,animals that are hunted and eaten

animals that are hunted and eaten

Q5.
How many prey are there in this food chain?
An image in a quiz
one
Correct answer: two
three
four
Q6.
How many predators are there in this food chain?
An image in a quiz
one
Correct answer: two
three
four
Q6 UYSEG

6 Questions

Q1.
What does a food chain show?
how many organisms are in a habitat
Correct answer: feeding relationships
how much biomass there is in each habitat
Correct answer: the flow of energy in a habitat
Q2.
What is each level in a food chain called?
An image in a quiz
Correct Answer: trophic, trophic level
Q3.
Match the organism to its description.
An image in a quiz
Correct Answer:apex predator,shark

shark

Correct Answer:producer,phytoplankton

phytoplankton

Correct Answer:primary consumer,zooplankton

zooplankton

Correct Answer:tertiary consumer,squid

squid

Correct Answer:secondary consumer,shrimp

shrimp

Q4.
Which organism is the producer in this pyramid of number?
An image in a quiz
a
b
c
Correct answer: d
Q5.
Who is right?
Sam: Pyramids of number are always perfectly pyramid shaped.
Correct answer: Lucas: Pyramids can be inverted because they don't consider organism size.
Izzy: There are always more organisms at the start of the food chain.
Laura: Pyramids of number can't be inverted because they consider organism size.
Q6.
How many grass plants are there in this pyramid of number?
An image in a quiz
7 000
16 000
Correct answer: 14 000