1. Module 1 Intro

1.11. Page 2

Lesson 2: Page 2

Module 1—Energy Flow and the Cycling of Matter

 

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Begin this lesson by reading page 16 of your textbook up to and including the left side of page 18. This information reviews what you have previously learned about feeding relationships in ecosystems. Organisms can be identified in many ways, such as through feeding relationships, and organisms can be organized into trophic levels. These levels also indicate the amount of energy available to organisms.

 

Self Check Self-Check


SC 1. Answer question 14 on page 16 of the textbook.


SC 2. Answer questions 15 and 16 on page 18 of the textbook.

 

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Self Check Self-Check Answers

 

SC 1.

  1. The first trophic level contains producers. The secondary trophic level contains primary consumers, while the third level is made up of secondary consumers. Tertiary consumers are in the fourth level, and the fifth trophic level is composed of quaternary consumers.

SC 2.

  1. Less energy is transferred from one trophic level to the next trophic level because from 80 to 95 percent of chemical energy is transferred to waste products and to the environment as heat during cellular respiration. This is summarized as the “rule of 10,” which means that approximately 10 percent of the initial energy at one trophic level will transfer to the next, a different trophic level.

  2. Food chains are limited in length because eventually the available transferable energy dwindles to nothing. An example is that 100 kJ energy −> 10 kJ energy −> 1 kJ energy −> 0.1 kJ energy, and so on.

 

Read Read


Continue reading from pages 18 to 24 in your textbook. Be sure to take note of the many different diagrams. These diagrams are a visual way of organizing and presenting the transfer of energy from one trophic level to another trophic level by showing biomass, the available energy, or the numbers of organisms. After these readings you will be asked to compare and contrast these diagrams and to use math to show energy flow through trophic levels.

 

Self Check Self-Check

 

Feeding Relationships

 

SC 3. How would you label this diagram? Scroll over each picture to see if you chose the correct terminology.

 



Virtual Ecosystem

 

SC 4. If you understand food chains, trophic levels, and the classification of producers and consumers, then you can skip this activity. If you are having difficulty, you should check this virtual laboratory.

 

Carefully read the questions and the procedure for the laboratory.

 

SC 5. Answer question 18 from page 24 of the textbook.

 

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Self Check Self-Check Answers

 

SC 5.

  1. An energy pyramid cannot be inverted. An energy pyramid shows the reduction in energy amounts at each trophic level rather than numbers of organisms or biomass. Energy is interpreted the same way by scientists, whereas biomass is not. There are no exceptions as to how energy is interpreted. Energy will ALWAYS be less as you move up through the trophic levels

 

Try This Try This

 

TR 1. In this activity you will construct, test, and compare two food chains. The first will be a northern food chain and the other will be a forest food chain. To access this activity you will need to do a web search. In your Internet search engine, type in the keyword “ecokids.” Choose the “.ca” website. Using the Ecokids website search bar, type in the keywords “chain reaction.” Choose the first activity that appears in your search, or access “Chain Reaction—Build a Food Chain.”

 

To support this comparison, access this interactive activity. While it provides a simple explanation of food chains, it does model the effect of losing trophic levels in a food chain. This is valuable in identifying the differences between the arctic and the forest food chains.

 

Record your answer and save it to your course folder.