Food Chains to Food Webs

This lesson was prepared For OCS Biology Class

by Linda Moore

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All of the energy for the life processes of living things originates from the sun.

The Sun is important because it warms the Earth. More importantly, the sun provides the energy that green plants use to produce food. Plants use

some of the food they produce. Animals cannot use the sun to make food in the same way that plants can. How do animals get their energy?

Animals (consumers) get energy when they eat plants (producers) and other animals.

A food chain organizes living things by where they get their food.

Remember this food chain?

A food chain is like a path on a map. If you follow the arrows, you can figure out the path

each organism takes to get its energy. The arrows show who gets eaten by whom.

But, there’s a problem with food chains.

There’s a lot more to the story of eating and being eaten!

How can we tell more of the story?

In nature, living things move around and eat more than one kind of food. So, we need a way of looking at more than one food chain at a time. A diagram that has more than one food chain at the same

time is called a food web. You know what a web looks like. Imagine

following a line on the web to the middle and back. Now, imagine following a line around the web and coming back to the starting point. There are many paths.Food webs also have many paths. Each path is called a food chain. Now, let’s use this information to look at a food web.

Ta Da!A Food Web

• How Just like you did on the spider web, trace one path at a time with your finger on yourworksheet. Start with the plant (producer). Follow the arrows to figure out who gets eaten by whom. Then, go back to the producer and follow a different path to get to the eagle. Each path is one food chain. How many different food chains can you find in this food web?

Let’s look at the food web one food chain at the time. Trace each food chain starting on the right side of the food web.

Hint: All of the food chains end up at the eagle!Would highlighting them help?

1. plant 1st level rabbit 2nd level eagle2. plant 1st level bluebird 2nd level eagle3. plant 1st level snail 2nd level bluebird 3rd level eagle1. plant 1st level caterpillar2nd levelbluebird3rd level eagle2. plant 1st level caterpillar2nd level lizard3rd level eagle

Trace them again until you are sure you can find all five of the food chains in this food web. After practicing, fill in the worksheet for

all five food chains that make up this food web. Put the producer and each consumer in its place on the worksheet.

The End

Congratulations!

You have completed the Food Web Lesson!

I’m very proud of you!