Food Webs and Energy Flow

Overview

This is a self-contained, no-technology substitute packet for Grade 4. Working alone with a pencil, students explore a meadow food web. They learn that energy starts with the Sun, that producers (plants) make their own food, consumers eat other living things, and decomposers break down dead things. They read that a food-web arrow means "energy goes to" and points toward the eater. Then they label each organism, trace a food chain, predict what happens when one living thing is removed, and write a short evidence-based explanation. There are no lab materials and no hazards — it is a paper investigation.

Accessible version of the student activity

The full student activity is reproduced below in plain, screen-reader-friendly HTML. It reflows on phones and at 200% zoom. Write your answers on the printed packet.

Start (5 minutes) — Notice & Wonder

1. In a meadow you might see grass, a grasshopper, a mouse, a hawk, and an owl. Write one thing you notice about what eats what.
2. Write one thing you wonder. Start with the words "I wonder…".

Build (5–10 minutes) — Read the science

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. 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; a mushroom and an earthworm are decomposers.

A food web is a picture that shows what eats what, using arrows. An arrow means "energy goes to." The arrow points from the thing that is eaten to the thing that eats it. For example, grass → grasshopper means energy goes from the grass to the grasshopper that eats it. 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.

• Sun → grass — the grass uses the Sun's energy to make its food.
• grass → grasshopper — the grasshopper eats the grass.
• grass → mouse — the mouse eats the grass.
• grasshopper → mouse — the mouse eats the grasshopper.
• grasshopper → hawk — the hawk eats the grasshopper.
• mouse → hawk — the hawk eats the mouse.
• mouse → owl — the owl eats the mouse.
• mouse → mushroom — when the mouse dies, the mushroom breaks it down.

3. Look at Figure 1. The arrow from grass to grasshopper means energy goes which way? Fill in: energy goes from the ______ to the ______.

Apply (20 minutes) — Use the food web

4. Label each living thing: write P for producer, C for consumer, or D for decomposer — for grass, grasshopper, mouse, hawk, and mushroom.
5. Trace one energy path. Follow the arrows to write one food chain inside the web, starting with the Sun and using three more living things, in order with arrows: Sun → ______ → ______ → ______.
6. What if all the grass dries up and is gone? What happens to the grasshopper? Use the food web to explain why.
7. Observation or inference — write O (something you see) or I (an idea you figure out):
   • 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 (5–10 minutes) — Claim, Evidence, Reasoning

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 (5 minutes) — ACE

• Articulate: in your own words, what does an arrow in a food web mean?
• Connect: point to one producer and one consumer in Figure 1; write their names.
• Extend: where does the energy in this whole food web first come from?

Continue (optional, ~15 minutes) — Early finisher

Add a rabbit to the meadow food web. Draw the arrows that show its energy: what does the rabbit eat, and what might eat the rabbit? Each arrow points toward the eater. Label the rabbit as a producer, consumer, or decomposer.

Turn in

Hand in the whole packet with your name, class, and date, with questions 1–8 and the ACE box answered. Include the optional drawing if you did it.