Students’ Learning Outcomes
· Define producers, consumers and decomposers and explain their importance in food chain.
· Make a simple food chain to show relationship among producers, consumers and decomposers.
Information for Teachers
· Plants are called producers because they are able to produce food (glucose) from carbon dioxide and water in the presence of sun light.
· Animals can’t make their own food so they must eat plants or other animals. That’s why they called consumers.
· Consumers can be divided into three groups;
v Animals that eat only plants are called herbivores or consumer-I e.g. rabbit, sheep, goat, cow etc.
v Animals that eat other animals (herbivores) are called carnivores or consumer-II e.g. lion, leopard etc.
v Animals that eat other animals (carnivores) are called consumers-III e.g. snake, hawk etc.
· Animals feed on dead body of plants and animals and after decomposition convert them into simpler compound, are called decomposers e.g. bacteria and fungi.
· A food chain is the sequence of “who eats whom” in an environment e.g.
· Arrows represents the energy flow in a food chain.
· If one part of a food chain alerts, the whole food chain is affected. For example, if a disease suddenly wiped out butterfly caterpillars, it would affect owls, eagles and many other animals.
Grass———-butterfly Caterpillar ———-Owl————Eagle
Material / Resources
Pictures of animals and plants, charts of food chain, papers, textbook
Worm up Activity
· Ask questions relevant to the topic:
v From where do we get our food?
v Why do we need food?
v What do plants and animals get their food?
v From where do animals get their food?
v From where do plants get their food?
v How we, animals and plants are related to each other?
· To make food chain, draw relation among plants, animals and man e.g.
Plants ————— Cow —————–Man
Development
Activity 1
· Demonstrate some examples of simple food chains.
· Introduce the concept of plants as producers i.e. organisms that make their own food through photosynthesis.
· Introduce the concept of animals as consumers i.e. organisms that eat producers or other consumers.
· Explain the role of decomposers in all food chains.
· Ask students to make a food chain by making a sequence of the following organisms. The students will also mention the producer and the consumers.
Activity 2
· Introduce a complex food chain i.e. with more than one consumer. Categorize the consumers as consumer- I, II, III and so on.Activity 3
· Reinforce the learning of food chain through the following role-play:
v Write the word producer, herbivore, carnivore-I, carnivore-II and carnivore-III on a separate paper.
v Give one paper to each student.
v Whatever the paper says, that becomes the student’s role in the food chain.
v Paste the paper to their backs.
v Herbivore tries to catch the producer. When a producer gets tagged the two students link arms.
v Carnivore-I tries to catch the herbivore and when he / she is successful, they link arms.
v Carnivore-II tries to catch the carnivore –I and when he / she is successful, they link arms.
v Similarly, carnivore-III tries to catch the carnivore-II and when he is successful, they link arms.
· Ask students to draw the developed food chain on paper.
Sum up / Conclusion
· Each living thing, whether it is a plant or animal, depends on nutrients and energy to survive.
· Food chain tells us how the food is passed from organism to organism.
· All food chains start with plants that make their own food. These are called producers.
· Next come organisms that eat plants. These organisms are called consumer-I and we know that they are herbivores.
· Then come the animals that eat herbivores. These are called consumer-II and we know that they are carnivores.
· In all food chains; when any organism dies, it is eaten and broken down by decomposers. Some bacteria and fungi are decomposers.
Assessment
Activity 1
· Ask students to make corrections in the following food chain
Activity 2
· Make a table on the board and ask students to copy the table on their note books.
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Consumer-II
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Organism that feeds on plants
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Consumer-I
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Order in which food passes from one living thing to another
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Producer
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Break down the dead body of animals and plants
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Food chain
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Living organism that is capable of manufacturing its food
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Decomposer
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Organism that eats animals
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Activity 3
· Ask students to make a correct sequence of plants and animals in the following activities (or the similar ones). If pictures are not available, write the names of these organisms on the board.
Follow up
· Ask students to complete the food chains by filling in the blank boxes with the correct consumers or producers given in the underneath food chains.
Food chain 1:
Grasshopper, Grass, Hawk, Snake, Rat
Food chain 2:
Birds, Cat, Snail, Grass algae
Food chain 3:
Grass, Fox, Rabbit, Bear
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Types of organisms
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Food chain 1
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Food chain 2
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Food chain 3
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Producer
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Consumer –I
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Consumer-II
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Consumer-III
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Ask the students to separate different food chains in the following diagram.
