Name
Date
Threads of Life
A food chain is a series of organisms woven together
according to the order in which they feed on one another. A
green plant is called a producer because it traps and stores
energy. An animal that eats plants is called a primary consumer.
That animal can get eaten by a secondary consumer, or an animal
that eats other animals. The animal at the top of the food chain is called
a tertiary consumer.
Directions: Look at the pyramid at the bottom of this page. Cut out each box along the
bold lines. Next, rearrange the boxes according to the appropriate group or level to which
each belongs—producer, primary consumer, secondary consumer, or tertiary consumer.
Glue your correctly organized pyramid onto another sheet of paper. Label each level, and
then use the new pyramid to answer the questions below.
1. This type of pyramid shows the trophic levels of an ecosystem. A trophic pyramid shows
how energy is transferred from one level to the next. Which trophic level of your pyramid
do you think has the most energy? ________ Least energy? ________ Explain your
answers. _______________________________________________________________
_______________________________________________________________________
2. The sun is a source of energy too. Is it a producer or a consumer? _________ Where
would you add it to the trophic pyramid? _______________________________________
3. In this trophic pyramid, which animal is the top predator? _________
4. The owl is a secondary consumer when it eats a _________. It is a tertiary consumer
when it eats a _________.
plants
weasel
mouse
mouse
berries
seeds
rabbit
flowers
grass
weasel
squirrel
©The Mailbox • www.themailboxcompanion.com • April/May 2008
marten
owl
Ecology: food chains, trophic pyramid
Answer Key for “Thread of Life”
Order of pictures may vary, but each should be in the appropriate level.
owl
weasel
mouse
berries
marten
squirrel
flowers
weasel
rabbit
plants
mouse
seeds
grass
Answers may vary. Accept reasonable responses.
1. The bottom level of producers is larger, so it must have the most energy. The top
level with the owl must have the least energy because it is the smallest level.
2. The sun is the source of all energy. If it were included in the trophic pyramid, it
would appear under the grass, plants, seeds, etc.
3. The owl is the top predator.
4. mouse, rabbit, or squirrel; weasel or marten
©The Mailbox • www.themailboxcompanion.com • April/May 2008