Life Cycle - Natural Environment (5B)
Pre Lab 

  • Comparing autotrophs and heterotrophs.
  • Defining a food web.
  • autotroph
  • consumer
  • food pyramid
  • heterotroph
  • producer
  • tropic level
  • worksheet
  • paper
  • scissors

Students make a diagram of consumers and producers. 


An ecosystem occurs when living animals, plants, and microbes form a community which includes producers and consumers.  Producers are those organisms that make their own food using sunlight, nutrients, and water.  Producers are autotrophs or organisms that utilize the sunlight and chlorophyll within the plant to produce energy for the plant to grow. Heterotrophs are those organisms on the food pyramid that eat producers.

Students have learned about coral and where they live.  Coral are consumers.  In some cases they depend on algae that grow within the coral for food in what is termed symbiotic relationships.  Coral are also debris feeders and rely upon whatever "falls" into their tentacles to be put in their stomachs.  The eating habits of coral are complicated.    

The food web concept is an extension of the food chain.  The food chain simply traces who eats whom within an ecosystem (a community of organisms interacting with one another and with their environment.  By itself, it doesn't give the whole picture of what is really going on in an ecosystem.  Many animals feed on several different types of food, humans eat several different kinds of plants and animals.  Because of these more complex eating patterns, different food chains intermix and form a "web-like" pattern called the food web. 

  1. Within the food web there are different tropic levels.  Students should cut out the pictures and glue a piece of paper into Producers, Primary Consumers, Secondary and Tertiary Consumer as in the diagram below.
  2. Tell the students that energy loss becomes greater as you go up the pyramid and the number of organisms becoming less in number as you go up. 
  3. Ask students what the difference between a carnivore and a top carnivore means.  A top carnivore could eat another organism that is also a carnivore.   A herbivore would be the producer.
  4. The answers are as follows:  Producers: 2,3,8; Primary consumers:5,6,10,11; Secondary Consumers: 1,4,9; Tertiary consumer: 7.


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