Science - Combined - 0653 CIE

Food Chains And Food Webs

Overview

Every meal is a transfer of energy. Trace your dinner backwards and you always arrive at the same place: a green plant capturing sunlight. Food chains and food webs are the maps biologists use to follow that energy as it passes from one living thing to the next, and they reveal something surprising, that most of the energy is lost at every step.

In this lesson you will name the feeding roles, build and read food chains and webs, draw the three kinds of ecological pyramid, and explain why energy leaks away so fast that food chains almost never have more than five links. You will also see why eating plants directly feeds far more people than feeding those plants to animals first.

Objectives

  1. [Core] Describe a food chain as showing the transfer of energy from one organism to the next, beginning with a producer
  2. [Core] Construct and interpret simple food chains
  3. [Core] Describe a food web as a network of interconnected food chains and interpret food webs
  4. [Core] Describe a producer as an organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis

Lesson Note

Food chains are not just diagrams to memorise. They tell you what will happen to a whole community if one species is removed, why a top predator is always rare, and why it is more energy efficient for a growing human population to eat crops than meat. Examiners reliably ask you to read a food web, name organisms by their feeding role, and explain energy loss between trophic levels, so the reasoning here earns real marks.

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Lesson Evaluation

Congratulations on completing the lesson on Food Chains And Food Webs. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.

You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.

Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.

  1. In a food chain the arrows show the direction of: A. movement of animals B. transfer of energy C. loss of water D. the breeding season Answer: B
  2. Which organism always begins a food chain? A. a herbivore B. a carnivore C. a producer D. a decomposer Answer: C
  3. In the chain grass -> rabbit -> fox, the rabbit is the: A. producer B. primary consumer C. secondary consumer D. decomposer Answer: B
  4. On average, the percentage of energy passed from one trophic level to the next is about: A. 1% B. 10% C. 50% D. 90% Answer: B
  5. Food chains rarely have more than five trophic levels because: A. animals stop breeding B. too much energy is lost at each level C. producers run out of sunlight D. decomposers eat the top predators Answer: B

Available on the Green Bridge App

Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.

Full lesson notes with diagrams
AI-powered learning assistant
Study offline, anytime, anywhere
Available on Android, Windows, macOS, and Linux

Available on the Green Bridge App

Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.

Full lesson notes with diagrams
AI-powered learning assistant
Study offline, anytime, anywhere
Available on Android, Windows, macOS, and Linux

Practice Mock Questions

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