Food Chains and Food Webs

What You'll Learn

Food webs show the complex feeding relationships in an ecosystem. Unlike a simple food chain, a food web shows that most organisms eat more than one type of food.

Key Words

producer
consumer
decomposer

Materials Needed

cups
water
plastic wrap
ruler
magnifying glass
paper towels

Safety First

Do not taste any materials.
Wear safety goggles when mixing liquids.
Wash hands after handling materials.

Steps

Step 1 — Read

Review the background information on Thermodynamics before starting.

Step 2 — Do

Set up a composting experiment: place food scraps in one sealed bag and leaves in another. Observe decomposition over two weeks and record changes.

Step 3 — Observe

Look for patterns in your observations.

Step 4 — Record

Make a graph or chart showing your results.

Check Your Understanding

Question 1

1 of 3

What is the main source of energy for most food chains?