1. Starter Activity: On a show me board answer these questions: 1.What does a food chain always start with? 2.What does the arrow in a food chain represent? 3.How much energy is passed on to the next level in a food chain? 4.Give an example of how energy is lost at each stage in a food chain.

2. Pyramids of biomass, energy and number. Learning Intention: Show the biomass, energy and numbers of organisms within a food chain as a diagram. Success Criteria: Define ‘Pyramid of biomass’ and construct one from data about a food chain. Define ‘Pyramid of energy’ and construct one from data about a food chain. Define ‘Pyramid of number’ and construct one from data about a food chain.

3. Why aren’t food chains very long? This tiger is a top predator; the final level in a food chain. Energy is lost at all levels in food chains. Animals at the top of a long food chain would not get enough energy to survive. Most food chains only contain four or five species, why is this?

4. Food chains and pyramids What can pyramids show about energy transfer?

5. Pyramids of numbers only give an accurate impression of the flow of energy in a food chain if the organisms are of similar size. Measuring the biomass at each trophic level can give a more accurate picture. Pyramids of numbers are a way of representing food chains. What are the problems of representing food chains in pyramids of numbers? They record the number of organisms at each feeding level in a specified area. What are pyramids of numbers?

7. In a pyramid of numbers, the length of each bar represents the number of organisms at each feeding level in a specified area. As a single tree can support many organisms, this food chain produces an irregular pyramid. numbers Understanding pyramids of numbers

8. biomass Understanding pyramids of biomass In a pyramid of biomass, the length of each bar represents the volume of organic matter – biomass – at each feeding level in a specified area. At each trophic level, the volume of biomass and energy available is reduced, giving a pyramid shape. The units of measurement is g/m².

9. energy Understanding pyramids of energy In a pyramid of energy, the length of each bar represents the volume of energy available– at each feeding level in a specified area. At each trophic level, the volume of biomass and energy available is reduced, giving a pyramid shape. The units of measurement is KJ/m²/year.

10. Irregular Pyramids There are some exceptions to the classis pyramid shape. These pyramids are said to be irregular. Some food chains have a single large producer e.g. a tree. Another exception is when a parasite is the top carnivore in the food chain: Fleas Fox Rabbit Lettuce Draw and label the irregular pyramid of numbers for this food chain: Oak tree  greenfly  ladybird  blue tit Irregular pyramid of numbers with a parasite.

11. Pyramids Task Draw and label each type of pyramid for each food chain: 1.Oak tree  Caterpillar  Blackbird  Fox 2.Green algae  Water flea  Tadpole  Trout 3.Grass  Aphid  Ladybird  Robin 4. Lettuce  Vole  Fox  Fleas

13. Pyramids of biomass, energy and number. Learning Intention: Show the biomass, energy and numbers of organisms within a food chain as a diagram. Success Criteria: Define ‘Pyramid of biomass’ and construct one from data about a food chain. Define ‘Pyramid of energy’ and construct one from data about a food chain. Define ‘Pyramid of number’ and construct one from data about a food chain.