Grade: Grade 3 Subject: Science Unit: Ecosystems SAT: ProblemSolving+DataAnalysis ACT: Science

Food Chains

Every living thing needs energy to survive. But where does that energy come from? Let's explore how energy moves through nature in something called a food chain!

What is a Food Chain?

🔗 A Food Chain Shows How Energy Moves!

A food chain is like a path that shows how energy travels from one living thing to another. It starts with the sun and moves through plants and animals!

Think about what you ate for breakfast. Maybe you had cereal with milk. The milk came from a cow, and the cow ate grass. The grass grew using energy from the sun! That's a food chain in action!

A Simple Food Chain

☀️ Sun
🌱 Grass
🐰 Rabbit
🦊 Fox

The arrow means "is eaten by" or "gives energy to"

Remember: Every food chain starts with energy from the sun! Plants use sunlight to make their own food through a process called photosynthesis.

Living Things in a Food Chain

Every living thing in a food chain has a special job. Let's learn about the three main roles!

🌿

Producers

Producers make their own food using energy from the sun. They are always at the beginning of a food chain!

Examples:

🌱 Grass, 🌻 Flowers, 🌲 Trees, 🌿 Bushes, 🌾 Wheat, 🥬 Lettuce

🐾

Consumers

Consumers cannot make their own food. They must eat other living things to get energy!

Examples:

🐰 Rabbits, 🦊 Foxes, 🐛 Caterpillars, 🦅 Eagles, 🐟 Fish, 🧒 People!

🍄

Decomposers

Decomposers break down dead plants and animals. They recycle nutrients back into the soil!

Examples:

🍄 Mushrooms, 🪱 Worms, 🦠 Bacteria, 🐌 Some snails

Types of Consumers

Not all consumers eat the same things! Scientists group consumers by what they eat.

🥬 Herbivores - Plant Eaters

Herbivores only eat plants. They are called primary consumers because they eat producers directly.

🐰 Rabbits eat grass | 🐛 Caterpillars eat leaves | 🐄 Cows eat hay | 🦌 Deer eat berries

🥩 Carnivores - Meat Eaters

Carnivores eat other animals. They can be secondary consumers (eat herbivores) or tertiary consumers (eat other carnivores).

🦊 Foxes eat rabbits | 🦅 Eagles eat mice | 🦁 Lions eat zebras | 🦈 Sharks eat fish

🥗 Omnivores - Plant AND Meat Eaters

Omnivores eat both plants and animals. This gives them more food choices!

🐻 Bears eat berries and fish | 🧒 Humans eat vegetables and meat | 🐷 Pigs eat plants and bugs

🌟 Fun Fact!

The word "herbivore" comes from Latin words meaning "plant eater." "Carnivore" means "meat eater," and "omnivore" means "everything eater!"

Energy Flow in Food Chains

⚡ Energy Travels Up the Food Chain!

Energy starts with the sun, moves to plants, then to animals that eat plants, and then to animals that eat those animals!

Here's something important: not ALL the energy passes from one level to the next. At each step, some energy is used up!

⚡ How Energy Decreases

Animals use energy to move, breathe, and stay warm. Only about 10% of energy passes to the next level!

☀️ Sun
100%
🌱 Producers
100%
🐰 Herbivores
10%
🦊 Carnivores
1%
This is why: There are usually more plants than herbivores, and more herbivores than carnivores. Each level needs LOTS of the level below to get enough energy!

Food Chain Examples

Let's look at some food chains from different places around the world!

🌲 Forest Food Chain

☀️ Sun
🌰 Acorn
🐿️ Squirrel
🦅 Hawk

🌊 Ocean Food Chain

☀️ Sun
🌿 Seaweed
🐟 Small Fish
🦈 Shark

🏜️ Desert Food Chain

☀️ Sun
🌵 Cactus
🐁 Mouse
🐍 Snake
🦅 Eagle

🌾 Grassland Food Chain

☀️ Sun
🌾 Grass
🦗 Grasshopper
🐸 Frog
🐍 Snake

Build Your Own Food Chain!

Now it's your turn! Click on organisms to add them to the food chain in the correct order. Remember: start with a producer!

🔨 Food Chain Builder

Producer
Herbivore
Carnivore

Practice Problems

Test your knowledge about food chains! Click the correct answer.

Question 1

What do we call living things that make their own food using sunlight?

Question 2

In the food chain: Grass → Rabbit → Fox, what is the rabbit?

Question 3

What do decomposers do?

Question 4

Where does ALL the energy in a food chain originally come from?

Question 5

An animal that eats BOTH plants and meat is called a:

Question 6

Which of these is a producer?

Matching Game

Match each organism to its role in the food chain! Click one item from each column to make a match.

🎯 Match the Organism to Its Role

🌱 Grass
🐰 Rabbit
🦊 Fox
🍄 Mushroom
Carnivore
Producer
Decomposer
Herbivore

Check Your Understanding

Why are there usually more plants than herbivores in an ecosystem?

What would happen if all the producers in a food chain died?

Put these in the correct food chain order:

🦅 Hawk, 🌱 Grass, 🐁 Mouse

What We Learned

🔗

Food Chains

Show how energy moves from one living thing to another.

🌿

Producers

Make their own food using energy from the sun.

🐾

Consumers

Must eat other living things to get energy.

🍄

Decomposers

Break down dead things and recycle nutrients.

☀️

Energy Source

All energy in food chains comes from the sun!

Energy Flow

Energy decreases at each level of the food chain.

Key Vocabulary: Food chain, producer, consumer, decomposer, herbivore, carnivore, omnivore, energy, photosynthesis

Next Steps

  • Look for food chains in your backyard or local park!
  • Think about what food chains include the food you eat
  • Draw your own food chains with different animals
  • Learn about food webs - when multiple food chains connect!
  • When ready, move on to learn about Ecosystem Balance!