Life Cycle - Natural Environment (3B)
Pre Lab 

  • Comparing how organisms obtain food. 
  • Defining characteristics of how organisms eat. 
  • carnivore
  • consumer
  • decomposer
  • herbivores
  • omnivore
  • producer
  • trophic level

Students determine trophic levels. 


Biomes have physical, as well as biological, characteristics that one must consider. The biological part of the system usually consists of four or five energy levels.  These are called trophic levels and are based on how far the original energy has come through the community.

The first level would be considered the producer level.  This is the part of the community that captures and stores solar energy in photosynthesis and releases oxygen.  The rest of the community is completely dependent upon this level.  The rest of the system are collectively called consumers, which are defined as "eating" their meals.

The second level would  consist of herbivores and can range in size from a small microorganism to an elephant.  Any organism that eats the producer is considered the second trophic level of the food chain.  

Carnivores are the third trophic level of the biological system.  The energy is now one more step removed from its original source.  There can be several trophic levels of carnivores.  A tiger can eat other smaller carnivores.  Some organisms, like man, are neither true carnivores nor herbivores, they care classified as omnivores, sometimes eating plant material and sometimes eating other animals.

Decomposers break down organic structures and substances, releasing compounds and elements back into the environments.  This group would constitute another trophic level.  

  1. Trophic levels help develop a flow of energy through any biological system.  Students can use the worksheet to develop their own levels of producers, decomposers, herbivores, and carnivores.  

  2. Read Working on a Food Chain and go over the vocabulary words.
  3. Instruct students to group the different organisms by cutting them out and sorting them into producers, decomposers, herbivores, and carnivores. 
  4. ANSWERS: Producers (3,8); Decomposers (1,6); Herbivores (7,9,10); Carnivores (2,4,5,11). 

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