Food Chains and Food Webs

Learning Objectives

By the end of this unit, you will be able to understand and explain two methods for illustrating how living things obtain the matter and energy they require. Specifically, you will learn that food chains represent how matter and energy move from producers to consumers within an ecosystem, highlighting the transfer of a single type of food in each chain link. Additionally, you will grasp the concept of food webs, which demonstrate the interconnectedness of multiple food chains in an ecosystem, showcasing how these chains are interlinked and connected.

A close-up of a grasshopper eating a thick blade of grass.

Grasshoppers eat grass and other plants to get the necessary matter and energy to survive.

© Jitti Thammajinda/Dreamstime.com

Lesson Summary

In this lesson, you will learn about two ways of showing how living things get the matter and energy they need. Food chains show the movement of matter and energy from producers to consumers in an ecosystem, but they can show only one kind of food in each part of the chain. Food webs show how the food chains in an ecosystem are connected.

A food chain with arrows from grass to an insect to a mouse to a snake to a hawk, with arrows from each to mushrooms.

Think about how energy and matter move through this ecosystem.

© Lukaves/Dreamstime.com; Photo illustration Encyclopædia Britannica, Inc.

Key Concepts

1. Food chains depict the transfer of matter and energy from producers to consumers within an ecosystem.

2. Food webs consist of numerous interconnected food chains, illustrating the complex relationships among producers and consumers and their interdependencies for energy and matter.

3. All living things in an ecosystem are connected through food chains and food webs.

A diagram has arrows connecting organisms to their food sources.

This food web shows that many living things can get the matter and energy they need by eating more than one thing.

Encyclopædia Britannica, Inc.

Background

In an ecosystem, matter and energy keep all living things alive. Food chains are like maps showing how energy and matter are passed from plants to animals. Plants, called producers, use sunlight to make food through a process called photosynthesis. Animals called consumers, eat plants or other animals to get energy. Each step in a food chain shows how energy and matter are transferred from one living thing to another.

But ecosystems are more than just food chains. They are made up of many interconnected relationships. Food webs help us understand these connections better. A food web is like a big puzzle showing how different food chains are linked. It helps us see how producers and consumers depend on each other for energy and matter.

Food chains and food webs show us that everything in an ecosystem is connected. Energy and matter travel through a network of interactions, and each living thing has an important role. Producers, like plants, take in sunlight and turn it into food. Consumers rely on producers for their energy. Sometimes, consumers become food for other consumers, showing how everything is connected.

Understanding these connections helps us see how delicate and important ecosystems are. We must protect and care for these relationships to keep ecosystems healthy and balanced.

A diagram shows a shark eating tuna, which eats both mackerel and small fish. Mackerel also eat small fish.

This food web shows how matter and energy move through a marine ecosystem.

Expedition Learn

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