1. Food Chains to Food Webs
This lesson was prepared
for Spring 2011 OCS Biology Class
by Linda Moore

2. T
All of the energy for the life processes of living things originates from the sun.
3. 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 cannotuse the sun to make food in the same way that plants can.How do animals get their energy?
4. Animals (consumers) get energy when they eat plants (producers) and other animals.
A food chain organizes living things by where they get their food.
5. 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.
6. But, theres a problem with food chains. Theres a lot more to the story of eating and being eaten!
7. How can we tell more of the story?
In nature, living things move around and eat more than one kind of food.So, weneed a way of looking at more than one food chain atatime. 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 aline 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, lets use this information to look at a food web.
8. Ta Da!A Food Web
How
Just like you did on the spider
web, trace one path at a time
with your finger on your
worksheet. 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?
9. Lets 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?
plant1st levelrabbit2nd leveleagle
plant1st level bluebird2nd level eagle
3.plant1st level snail2nd level bluebird3rd leveleagle
plant1st level caterpillar2nd levelbluebird3rd level eagle
plant1st level caterpillar2nd levellizard3rd leveleagle
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.
10. The End
11. Congratulations!
You have completed the Food Web Lesson!
Im very proud of you!