Measuring the World · Summer Term

Perimeter of 2D Shapes

Calculating the perimeter of various polygons and composite shapes.

About This Topic

Food chains and webs illustrate the complex interdependence of organisms within an ecosystem. Students learn how energy from the sun is captured by producers and passed through various levels of consumers. They also explore how changes in one part of a food web can have far-reaching consequences for the entire system.

This unit aligns with the National Curriculum targets for relationships in an ecosystem. It provides a foundation for understanding biodiversity, conservation, and the impact of human activity on the natural world. Mastering the concept of energy flow is essential for students to appreciate the delicate balance of life on Earth. Students grasp this concept faster through structured discussion and peer explanation, where they can model the impact of environmental changes.

Active Learning Ideas

Simulation Game: The Living Food Web

Students are assigned roles as different organisms in an ecosystem. They use balls of string to connect themselves to their food sources, creating a physical web. The teacher then 'removes' one organism to show the impact on the rest of the web.

⏱ 30 min·Whole Class

Generate mission

Inquiry Circle: Owl Pellet Dissection

Groups dissect owl pellets to identify the remains of prey. They use their findings to construct a food web for the owl's ecosystem and discuss the role of the owl as a top predator.

⏱ 60 min·Small Groups

Generate mission

Think-Pair-Share: The Vanishing Bee

Students are given a scenario where the bee population in an area has declined. They work in pairs to predict the impact on local food chains and human food supplies, then share their ideas with the class.

⏱ 20 min·Pairs

Generate mission

Watch Out for These Misconceptions

Common Misconception

The arrows in a food chain show what eats what.

What to Teach Instead

Clarify that the arrows represent the direction of energy flow, from the organism being eaten to the consumer. Using the phrase 'goes into the belly of' can help students remember the correct direction of the arrow.

Common Misconception

A change in one population only affects its direct predator or prey.

What to Teach Instead

Explain that ecosystems are highly interconnected, and a change in one species can have 'cascading' effects throughout the entire web. The string-web simulation is an excellent way to visualise these indirect connections.

Frequently Asked Questions

What is the difference between a food chain and a food web?

A food chain is a simple, linear sequence showing who eats whom in an ecosystem. A food web is a more complex and realistic model that shows the interconnected food chains within an entire community, reflecting that most organisms eat more than one type of food.

How do active learning strategies improve understanding of ecosystems?

Active learning, such as creating a 'Living Food Web' with string, makes the abstract concept of interdependence tangible. When students see how pulling on one string affects many others, they gain a much deeper understanding of the fragility and complexity of ecosystems than they would from a static diagram.

What is a producer in a food chain?

A producer is an organism, usually a green plant or algae, that makes its own food using energy from sunlight through the process of photosynthesis. Producers are the foundation of almost all food chains on Earth.

Why is energy lost at each level of a food chain?

Energy is lost at each level because organisms use it for life processes like movement, growth, and maintaining body temperature. Much of the energy is also lost to the surroundings as heat, which is why food chains rarely have more than four or five levels.

Browse curriculum by country

• Americas
• US
• CA
• MX
• CL
• CO
• BR

• Europe
• UK
• IE
• FR
• DE
• ES
• IT
• NL
• PT
• SE

• Asia & Pacific
• IN
• SG
• AU