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Starter. Can you sort the cards in front of you into the correct definitions? When you think you have them in the correct order, add these definitions to the glossaries in the back of you books. A few key words…. Pyramids of Biomass Learning Objectives
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Starter Can you sort the cards in front of you into the correct definitions? When you think you have them in the correct order, add these definitions to the glossaries in the back of you books.
Pyramids of Biomass Learning Objectives Construct and interpret pyramids of biomass Describe how energy and mass is transferred along a food chain Explain why energy and biomass is reduced at successive stages in a food chain
Every living organism needs energy to survive – but where does it come from?
Radiation from the Sun (solar or light energy) is the main source of energy for all living things. The Sun’s light energy is captured and used by green plants and algae during photosynthesis, to make new biomass. Biomass is the dry mass of living material in an animal or plant.
Biomass is the mass of material in living organisms. Ultimately all biomass is built up using energy from the sun. Biomass is often measured as the dry mass of biological material in grams. The biomass made by plants is passed on through food chains or food webs. It goes into the animals that eat the plants. It then passes into the animals that eat other animals. In a food chain there are usually more producers than primary consumers, and more primary consumers than secondary consumers.
We can draw this as a Pyramid of Numbers. However the number of organisms at each leveldoes not accurately reflect what is happening to theBiomass.
A pyramid of biomass is a chart, drawn to scale, showing the biomass at each stage in a food chain. The bars become narrower as you reach the top. This pyramid of biomass is for the food chain: oak tree → caterpillar → blue tit → sparrowhawk Note that you do not need to draw the organisms. But you must draw your pyramid of biomass to scale. Each bar should be labelled with the name of the organism.
Construct your own Pyramid of Biomass: Count up the number of leaves. Each leaf weighs 5g.
Construct your own Pyramid of Biomass: Now count the number of aphids that can eat that amount of leaves in one day. Each Aphid weighs 1g
Now count the number of lady birds that can eat that amount of aphids in one day. Each Ladybird weighs 10g
Construct your own pyramid of biomass Plot a bar chart on graph paper that shows the biomass of each organism. Cut out each coloured bar and stick it into your book to create a scaled pyramid of biomass – starting with leaves at the bottom, then aphids, then lady birds at the top Answer these questions that interpret your pyramid: What percentage of the biomass of the leaves is passed on to the aphids? What percentage of the aphids is passed on to the ladybirds?
Count up the number of caterpillars. Each caterpillar weighs 10g.
Findings from our pyramids of biomass Q1. What is happening to the biomass as we go up the food chain? Q2. What is happening to the energy as we go up the food chain?
Findings from our pyramids of biomass The amount of material and energy contained in the biomass at each stage is less than it was at a previous stage. This is because some material and energy taken in is passed out as waste by the organism. A lot of the biomass eaten is used in respiration by the animal cells to release energy, and used for growth and movement.
Plenary The amounts of ______ and _______ contained in living things always gets less at each stage of a food _______ from ________ onwards. Biomass is lost as ________ products and used to release energy in _______. This is used for _______ and to control body __________. Only a small amount is used for _________. biomass temperature energy chain growth movement producers respiration waste
Plenary The amounts of biomass and energy contained in living things always gets less at each stage of a food chain, from producers onwards. Biomass is lost as waste products and used to release energy in respiration. This is used for movement and to control body temperature. Only a small amount is used for growth.
Pyramids of Biomass Learning Objectives Construct and interpret pyramids of biomass Describe how energy and mass is transferred along a food chain Explain why energy and biomass is reduced at successive stages in a food chain