1. Feeding relationships
Food chains
We will be talking about the transfer of energy through an ecosystem- food chain
Rabbit, fox & grass
To probe student prior knowledge of food chains, before displaying the “grass, rabbit, fox” picture, I would ask students to arrange the words “rabbit, fox and grass” into a food chain. I would then ask the class which way the arrows should go by getting them to vote by pointing either left of right. This would indicate their current knowledge and if they already know which way the arrows should face and what they mean.

2. Source of energy The original source of all energy is the sun
Green plants and algae produce food
They are called producers
Producers produce their own food from non-living substances such as light.
What is the name of the
process where plants get
energy from the sun?
Our source of energy?
Ask- “What is the process where plants obtain energy from the sun?”

3. Flow of Energy Energy only moves in one direction within the food
chain.
The links within the food chain are known as ‘trophic levels’
Organisms that can’t produce their own food are know as consumers.

4. Flow of Energy
Producers are green plants and algae – eg. grass First order consumers- herbivores- eg. grass hoppers Second order consumers – carnivores- eg. toad Third order consumers are carnivores – eg. snake *it is possible for an animal to belong to more than one group.
Ask- “What is a herbivore?” Organisms that eat only plants
“What is a carnivore?” Organisms that eat only meat of other animals
“What is an omnivore?” Organisms that eat animals and plants.

5. Flow of Energy Food Pyramid Where do producers gain their energy?
When consumers eat producers, this energy is passed up the food chain.
Some of this energy is lost at each stage (eg. heat, wastes). This means that not all the energy from the sun reaches the top consumer
If energy is lost at each level, how does energy reach the top consumer?

6. Rabbits which are eaten by Owls
Food chain: a flow of energy in a habitat
Grass is eaten by
Rabbits which are eaten by
Owls
Owl
Grass
Rabbit
Quiz students about direction of arrows before displaying them.
The arrows show the direction of energy flow.

7. Flow of Energy Examples of food chains Owl, mouse, grass & snake
Leaves, frog, slug & heron
Plant, bird, spider, cat & ants
With these examples, I would get students to arrange the organisms into a food chain, add arrows between trophic levels and get students to label each organism as producers, 1st order consumer, 2nd order consumer or 3rd order consumer.

8. Pondweed small fish Heron Insect larvae
Using these picture prompts, I would ask students to help me order these organisms on the board. Same again, putting in arrows and labeling the organisms as producers & consumers etc.
small fish
Heron
Insect larvae

9. Insect larvae Minnow (little fish) Pondweed Heron
e.g.

10. Food webs Sometimes we need to join a number of food chains together.
This is when many animals eat more than one kind of food.
-What does the hawk eat?
-Which animals are the herbivores?
-Are these 1st, 2nd or 3rd line consumers?

11. How many food chains are there now?
Weasel
Plant
matter
Shrew
Owl
Rabbit
Grass
Worm
Snail
Hedgehog
Fox
Write down as many food chains you can find within
this web. What do you start with in a food chain?

12. Shrew Weasel Fox Grass Shrew Weasel Fox Shrew Owl Shrew Owl Grass
Plant
matter
Shrew
Weasel
Fox
Grass
Shrew
Weasel
Fox
Plant
matter
Shrew
Owl
Shrew
Owl
Grass
Plant
matter
Hedgehog
Fox
Worm
Plant
matter
Hedgehog
Fox
Snail
Rabbit
Fox
Grass
Grass
Rabbit
Fox

13. Decomposers
Decomposers break down and recycle matter within their ecosystem, so that plants can reuse the nutrients.
Decomposers return nutrients from dead plants and animals into the soil  plants.
Examples: bacteria, fungi & worms.

14. Detritivores
Detritivores eat small particles of dead plant and animal matter. They also eat animal waste products. Detritivores include: worms, insect larvae, snails and some crustaceans.