Fremont Magnet Elementary

Back to 4th Grade Science

Food Chains

Standard 2a Students know plants are the primary source of matter and energy entering most food chains

Standard 2b Students know producers and consumers (herbivores, carnivores, omnivores, and decomposers) are related in food chains and food webs and may compete with each other for resources in an ecosystem
 

1. Review

Last week you learned how plants and animals help each other survive.

 

Which animal is most likely to disperse the seeds found in berries?

  caterpillar
  bee
 
bird

For which of the following do many plants depend on animals?
 

  photosynthesis
 
shelter
 
seed dispersal

 

2. What is a food chain?

Every living organism needs energy to live.  Plants get their energy from the Sun, some animals get their energy from eating plants, and other animals get energy from eating other animals. A food chain is a way of organizing living things by what they eat.  It shows who's eating who.  The arrows in a food chain show the flow of energy.

 

Everything in the food chain is either a producer or a consumer.

To find out what a producer and consumer are click here and do the Revisewise activity.

Here is a brainpop movie about food chains

3. Types of consumers

Now you know that food chains begin with plants (producers).  Plants are a primary source in food chains; that means they are at the beginning of the food chain.  Anything that eats  plant or animals is called a consumer.

There are 3 types of consumers

  • herbivore
     
  • carnivore
          
  • omnivore
           

Think Time...

Which do you think has the best chance of surviving during tough times?

  herbivore
 
carnivore
  omnivore

 

4. Animal and Plant Survival

If something on the food chain disappears it causes a problem for all the other animals on the food chain. 

For example, if the grass dies because there isn't enough rain then the deer won't have enough food to eat.  If the deer starve, then the carnivores that eat them will also go hungry.
If birds disappear, then the insects that they normally eat will increase.  The insects will then eat too much of the plant life, causing a shortage of food for other plant eaters.

   

Click here to try it

Here is pond you can play with

 

Think Time...

This is a food web.  Like a food chain, it shows the flow of energy.  It starts with a primary source, a producer.  It shows two consumers that eat the producer, the mouse and the grasshopper.

If all the snakes were eaten, which animal will most quickly be threatened by starvation?

If all the snakes were eaten, which animal population would most likely increase?

Build a food web

5. Now try this

Which of the following organisms could be the primary source of energy for a food chain?

  earthworm
  green algae
 
ladybug

 

Which category best describes an animal that only eats plants?
 

  producer
 
herbivore
  carnivore

Which of the following defines an omnivore?

  a special kind of carnivore
  a producer that eats meat
 
a consumer of plants and animals

 

Which of the following describes what a food chain shows?

  how animals move about in their community
  which foods in a community grow the best
 
how energy travels in a community

 

 

Here are some fun food chain activities to try

Harcourt Fun With Food Chains

Food Webs

Pictures of herbivores, carnivores, and omnivores