Food chains, food webs and energy transfers
This Topic is About...
- I will learn how to draw food chains.
- I will find out what food webs are and how food chains fit inside them.
- I will understand how food webs show who eats whom in nature.
- I will discover where energy comes from in food chains and food webs.
- I will explore how energy moves from one living thing to another.
Get ready to explore how energy flows through life!
Key Words
- accurate
- food chain
- food web
- represent
Tap to Learn the Meanings!
- accurate: Correct and true, with no mistakes.
- food chain: A line that shows who eats whom in nature.
- food web: A group of food chains linked together in an ecosystem.
- represent: To show or stand for something else.
Great job learning new science words!
Understanding Food Chains
Afood chain is a diagram that shows the order in which animals eat plants and other animals to get energy. A food chain is made up of pictures and/or words to show or represent the plants and animals, with arrows linking them. The arrows show the direction in which the food moves. Food contains energy, so the arrows also show the direction in which the energy is transferred.
Producers and Consumers
Food chains always contain a producer and at least one consumer. The order of living things in a food chain is always:
The Energy Flow: $\text{producer} \rightarrow \text{consumer}$
How Energy Moves
Energy is always transferred from the producer to the consumer because the consumer eats the producer. Most food chains have more than one consumer.
What Are Food Webs?
Do you eat only one kind of food? Most living things don’t eat just one food. For example, a frog will eat worms, flies, beetles, and other insects. Some large frogs will eat small snakes, mice, baby turtles, and even smaller frogs. This means that most animals are part of more than one food chain.
How Food Chains Connect
These different food chains link together to form a food web. Food webs are a more realistic or accurate way to show how energy is transferred between living things. A food web shows the different food chains that a living thing can be part of in its habitat.
Example: Rainforest Food Web
Look at the picture of a food web from the rainforests in Indonesia. It shows how animals and plants are linked by what they eat and how energy flows between them.
Think like a Scientist
Task: Explain a food web and draw food chains
Instructions: Look at the food web and answer these questions.
How am I doing?
Answer ‘Very well’, ‘Quite well’ or ‘I need help’ to these questions:
- How well can I identify producers and different consumers in a food web?
- How well can I identify and draw the food chains in a food web?
- How well can I explain the way a food chain or food web helps us to understand feeding relationships in nature?
👀 show answer
- Example answers:
- Producers: palm shoot, fig, jack fruit.
- Herbivores: fruit bat, spotted deer, orangutan.
- Carnivores: tiger, python, hawk.
- Omnivore: orangutan.
- The orangutan eats figs, jack fruit, and palm shoots.
- The tiger and python eat the orangutan.
- Food webs show how energy moves through many food chains that link together.
Great thinking! You’re learning to see how everything in nature is connected. 🌿
Energy Transfers in Food Chains
Energy is transferred from one living thing to another in a food chain. Producers get their energy from the Sun and use it to make food. That food becomes the source of energy for the herbivores that eat the plants, and the herbivores then become the source of energy for the carnivores that eat them.
Where the Energy Goes
Not all the energy in a consumer’s food is passed on to the next link. For a herbivore, some energy is used to stay alive and move, some is stored in its body, and some is released to the surroundings as heat. When a carnivore eats the herbivore, it only receives the energy stored in the herbivore’s body; the rest is lost from the food chain.
Less Energy at Each Link
Because energy is lost at each step of a food chain or food web, the amount transferred to the next link becomes smaller and smaller.
QUESTIONS
1. Where does the energy in a food chain or food web come from?
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2. How do producers use this energy?
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3. How is the energy in a producer transferred to a consumer?
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4. How does a consumer, such as a hawk, depend on producers?
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5a. What happens to the amount of energy as it is transferred through a food chain?
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5b. Say why this happens.