Activity Name

Objectives

To understand the way energy flows in an ecosystem
To explore the connections between different cycles and processes in an ecosystem

Method

Time

Materials

Steps

Watch the following videos on food chain

Discussion questions

When we say food web, what comes to your mind? Why do you think it is called food web?
What are the implications of laws of thermodynamics on how much energy is transferred in a food chain?
Can you think why there are few consumers and large number of producers? What happens when a consumer eats a producer?
In the local ecosystem, provide examples of each of these categories in your area – producer, consumer and decomposer?
For this web to work properly, what is needed?
What is energy flow? How does it flow – from small organisms to large or large organisms to small? Why do you think so? What elements do you observe in the ecosystem that give you this idea?
Is the tiger 'bad' because it ate the goats? Why is the tiger eating the goat?

Notes(optional)

The laws of thermodynamics we saw earlier govern the processes in a food chain also. For example, the first law tells us that an organism can only use the energy it receieves whereas the second law tells us that not all of the energy received by an organism can be used – some of it will be lost as heat. At each level of the food chain, the amount of energy that gets transferred to the next trophic level is only a portion of the energy present in the lower level. This fraction varies widely across ecosystems. When finally organisms die and decay they pass the materials of life in simple forms to other organisms (nutrient flow). This energy flow is not cyclic – continuously less and less energy is available. So then, how do ecosystems continue? They depend on an external source of energy called the Sun. If the Sun's energy is not available in usable form, life on Earth may not be possible any longer.

Toer energy activity 9

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