KS3 SCIENCE
Curriculum link: Interactions and
Interdependencies (Relationships in an
ecosystem)
FOOD CHAINS AND WEBS LESSON PLAN
Introduce students to food webs and food chains using the wildlife of Galapagos for illustration. This section
explains how energy transfers through ecosystems as a result of consumption.
Resources required: Species photo cards, Food Web handout, online interactive, Food Chain handout
1. FIRE STARTER
Recap key words such as: producer, primary
consumer, secondary consumer and apex predator.
Using the ‘species photo cards’ and ‘food web handout’,
ask students to match the key words to the relevant
organisms. Ask students to order the species cards
to show which species consume which other
species, or ‘who eats who?’
2. GAINING GROUND
Explain that energy is transferred through an
ecosystem by consumption. Introduce food chains
and food webs as a way of visualising this transfer.
Be sure to emphasise the direction in which energy
flows, and therefore the direction in which the
arrows point. Students can then work through the
online interactive on the Discovering Galapagos
website.
3. MAKING WAVES
Present students with population pyramids based both
on numbers and biomass. Ask students to describe and
explain the differences between the two pyramids.
Encourage them to discuss the loss of energy and
biomass that occurs along the food chain.
4. FUTURE FOCUS
Individually, students should fill in the ‘food chain
handout’. They should also choose 10 species
mentioned on Discovering Galapagos, which they
should then use to create their own annotated food
web of Galapagos.
A RESOURCE BROUGHT TO YOU BY THE GALAPAGOS CONSERVATION TRUST (REGISTERED CHARITY NO. 1043470) AND THE ROYAL GEOGRAPHICAL SOCIETY (WITH IBG)
LEARNING OBJECTIVES
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To know that energy is transferred up the
trophic levels through consumption.
To understand how food chains and food
webs can illustrate energy transfer
between species.
To appreciate that energy transfer
between trophic levels involves loss of
energy and decrease of biomass.
STUDENTS’ OUTCOMES
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To give examples of the different habitat
zones found in Galapagos.
To explain how food chains and food webs
illustrate the transfer of energy between
species.
To discuss the decreasing biomass of the
higher trophic levels. Students should
refer to population numbers.