Food Webs and Energy Flow
Start Here
This is a paper science activity. You will read a little, look at a picture, and answer questions with a pencil. You do not need a computer or any supplies. Work by yourself and do your best. If a question is hard, skip it and come back. You may read the words out loud to yourself.
Start Notice & Wonder 5 min
Think about a grassy meadow with animals living in it.
1In a meadow you might see grass, a grasshopper, a mouse, a hawk, and an owl. Write one thing you notice about what eats what.
2Write one thing you wonder. Start with the words "I wonder…"
Build Read the Science 5–10 min
How energy moves in a food web
Every living thing needs energy to grow and move. In a meadow, that energy starts with the Sun.
- Producers make their own food using sunlight. Plants like grass are producers. They are the start of the food.
- Consumers cannot make their own food, so they eat other living things. A grasshopper, a mouse, and a hawk are consumers.
- Decomposers break down dead plants and animals and put nutrients back into the soil. A mushroom and an earthworm are decomposers.
A food web is a picture that shows what eats what. In a food web we draw arrows. An arrow means "energy goes to." The arrow points from the thing that is eaten to the thing that eats it.
grass → grasshopper means "energy goes from the grass to the grasshopper that eats it."
Tip: the arrow always points the same way the energy travels — toward the eater.
Word Bank
- producer
- a living thing that makes its own food from sunlight, like a plant.
- consumer
- a living thing that eats other living things for energy.
- decomposer
- a living thing that breaks down dead plants and animals.
- energy
- what a living thing needs to grow and move.
- food web
- a picture with arrows that shows what eats what.
3Look at Figure 1. The arrow from grass to grasshopper means the energy goes which way? Fill in the blank: energy goes from the ______________ to the ______________.
Apply Use the Food Web 20 min
Use Figure 1 on the page before to answer these questions.
4Label each living thing. Write P for producer, C for consumer, or D for decomposer.
____ a) Grass
____ b) Grasshopper
____ c) Mouse
____ d) Hawk
____ e) Mushroom
5Trace one energy path. Follow the arrows to write one food chain that is inside the web. Start with the Sun and use three more living things. Write them in order with arrows.
Sun → ____________ → ____________ → ____________
6What if? Imagine all the grass in the meadow dries up and is gone. What do you think happens to the grasshopper? Use the food web to explain why.
7Observation or inference? An observation is something you see. An inference is an idea you figure out. Write O or I for each.
____ a) In the food web there is an arrow from the mouse to the hawk.
____ b) The hawk gets some of its energy from the mouse.
____ c) The mushroom grows on the dead mouse.
Explain Claim–Evidence–Reasoning 5–10 min
Question 8. A sickness makes all the mice in the meadow disappear. Predict what happens to the hawk. Use the food web as your evidence.
Sentence starters you may use: "I think the hawk will…" · "In the food web I see an arrow from…" · "This will happen because…"
Close ACE Wrap-Up 5 min
In your own words, what does an arrow in a food web mean?
Point to one producer and one consumer in Figure 1. Write their names.
Where does the energy in this whole food web first come from?
Continue Early Finisher optional · ~15 min
Add a new living thing to the web. On the back of this page, draw a rabbit and add it to the meadow food web. Draw the arrows that show its energy. Think: What does the rabbit eat? and What might eat the rabbit? Remember, each arrow points toward the eater. Label the rabbit as a producer, consumer, or decomposer.