1. Module 1 Intro

1.10. Lesson 2 Intro

Lesson 2

Module 1—Energy Flow and the Cycling of Matter

Lesson 2—Energy Flow Through Trophic Levels and the Cycling of Matter

 

Get Focused

 

This graphic shows a cartoon version of an aquatic food chain. A large fish with big teeth chases a medium-sized fish which, in turn, appears ready to eat a small fish.

© Tomas Bercic/iStockphoto

Do you ever get the feeling that you are outnumbered? There are more plants, four-legged animals, and insects than there are of you. You get the picture. If you want to be philosophical about your presence in your own backyard, you are just one in a sea of thousands. But why are you outnumbered? Think about the complexity of your diet and what you know about energy flow. Hypothesize where you fit in terms of energy flow in the biosphere.

 

In Lesson 1 you learned that producers can use photosynthesis or chemosynthesis to fuel their life processes. Producers are the initial energy supplier for you, the consumer. You also reviewed cellular respiration and determined how it is used to access energy.

 

Of all the energy that Earth receives, Lesson 2 will focus on the small fraction of the Sun’s energy that is transferred from one organism to another within an ecosystem. You will study the flow of energy between producers and the various types of consumers. You will also find out how much energy is actually available from one trophic level to another within a food chain.

 

trophic level: describes the feeding level through which matter and energy are transferred; indicates an organism’s position in the food chain (e.g., producer, primary consumer, secondary consumer)


food chain: a diagram or model that uses a straight line to show how food (energy) transfers from producers to primary consumers to higher trophic levels

 

food web: a diagram or model that shows the connections among food chains (food/energy transfer) in an ecosystem

 

Consider the following essential questions as you complete this lesson:

  • How can you model the transfer of energy and matter between organisms?

  • How can you use math to explain the differences in energy flow in various ecosystem food chains?

Module 1: Lesson 2 Assignments

 

Your teacher-marked Module 1: Lesson 2 Assignment requires you to submit a response to the following:

  • “Investigation 1.B: Weave Your Own Food Web”

  • Choose ONE of the two Try This Thought Labs

  • TR 4

  • Discussion (if this is the discussion piece you decided would be for assessment)

You can access your Module 1: Lesson 2 Assignment. You can print off the assignment or save the download to your computer. Your answers can be saved on this document to your course folder.

 

You must decide what to do with the questions that are not marked by your teacher.

 

Remember that these questions provide you with the practice and feedback that you need to successfully complete this course. You may decide to respond to all the questions and place those answers in your course folder.