Food Chains & Food Web By: Cammie’s Corner

All living things need food for energy. You have read that the energy for all living things comes from the sun. Plants use the sun’s energy to make their own food. But how do other living things get that energy? How do you get food energy from the sun?

Food Chains A food chain is a model that shows the path of energy as it flows form one living thing to the next.  A model is something that stands for something else.  Notice that the food chain below begins with grass. Like all plants, grasses are producers.  Remember that a producer is a living thing that makes its own food. All food chains begin with producers.

The grass in the food chain uses the energy of sunlight to make its owns food.  The grass uses some of the energy in the food. It stores the rest of the food in its leaves.  When the grasshopper eats the grass, energy in the leaves moves into the grasshopper’s body. The grasshopper uses some of that energy to hop and find food. It stores the rest of the energy from the grass in its body. A grasshopper is a consumer. Recall that a consumer gets energy by eating other living things. All animals are consumers

When the snake eat the grasshopper, the energy in the grasshopper moves into the snakes body.  The snake uses some of that energy to stay warm, find food and move. The snake stores the rest of that energy from the grasshopper in its body.  Then the eagle eats the snake. The eagle uses some of that energy from the snake and stores the rest in its body.

Food chains end with decomposers.  Recall that a decomposer is a living thing that gets energy by breaking down material from dead plants and animals.  In the food chain, bacteria are decomposers.  When the snake dies, bacteria use some of the energy stored in its body. The bacteria also add nutrients to the soil. Except for the grass, each living thing in this food chain gets energy from another organism. But all of the energy starts with the sun

Food Webs A food chain is a model.  It shows the flow of energy from one living thing to the next. But real life is much more complicated than a food chain.  For example, most consumers do not get energy from just one kind of organism. In an ecosystem, the plants and animals in several food chains link together to form a food web

In this food web, the caterpillar is not the only one that eats the grass. The rabbit eats the grass too.  The bird also eats grasshoppers.  The rabbit is eaten by the fox and hawk.  When any of these plants and animals dies, the fungi and bacteria break down and add nutrients to the soil.

Most ecosystems have many different kinds of producers. They also have many different kinds of consumers and decomposers. That is why food webs include different kinds of producers, consumers and decomposers.

Moving Energy Energy moves through food chains and webs.  Plants and other producers take in energy form the sun to make their own food.  Energy goes from producers to consumers. It goes from plants to small animals to bigger animals to the biggest animals

Humans are part of many food webs.  Suppose you ate chicken for dinner last night. The energy in the chicken moved from the corn that the chicken ate to the chicken and then you.  Energy is stored in the food you eat.

Each animal gets and stores only part of the energy from the plant or animal it eats.  Not all of the energy in plants and animals moves through a food web or chain.  Some of the energy gets used along the way.  Animals use energy to keep warm, move around, and grow.  After they die, energy also goes from producers, to consumers to decomposers.  Bacteria and other decomposers get energy from dead plants and animals.

Did you know? Tiny bubbles that come up from the bottom of the pond are bubbles of gas called methane. This gas is given off as waste by decomposer bacteria that live in the mud on the pond bottom

Discussion Question: Describe or draw a food chain that ends with you. Explain how energy moves through your food chain.