Name ______________________________________ per _____ date ___________
 Food Chain – A food chain is the series of organisms in a line to show feeding relationships (energy
and matter transfer). Energy flows through an ecosystem in one direction- from producers to
consumers. The stability of an ecosystem depends on the presence of producers, since they convert
sunlight into energy the whole ecosystem can use- stored in organic molecules (sugars, starch,
glucose). A food chain begins with an organism that can photosynthesize to gain energy (producer),
which is then eaten by an organism as their source of energy (primary consumer). The arrow means
‘energy transfer’ i.e. is eaten by, and shows the direction of matter and energy flow along the food
chain. A significant amount of energy is lost every time energy is transferred, but we will discuss this
later. Decomposers are essential to every ecosystem as well but not shown in a food chain (more on
them later too).
 Trophic level: Each different ‘link’ in a food chain is a trophic level, Producers are the first trophic level
and each level after that is less and less energy efficient.
Example of a Food Chain
Grass (Producer) Grasshopper (primary Consumer)  Kookaburra (secondary consumer)
Questions
In the food chains below, identify the producer, the primary consumer and the secondary consumer,
write this on the line below each organism.
1.
GRASS ----------- SHEEP ---------
_______________
________________
COYOTE
_______________
2. PHYTOPLANKTON ---------- PRAWN (shrimp) -------- TUNA
_______________
_________________
___________________
3. Now list your own food chain (producer  primary consumer  secondary consumer 
tertiary consumer?) in each of the following biomes (use any organisms you believe to live there, try to
be specific and accurate as you can):
(a) Desert
(b) Rainforest
(c) Coral reef (Marine)
_____
(d) Chaparral _______________________________________
(e) Tundra _________________________________________
(f) Temperate deciduous forest _________________________
(g) Grassland ________________________________________
(h) Taiga ____________________________________________
(i) Freshwater stream ___________________________________
dragonfly larva
mussel
caddisfly larva
small fish
zooplankton
snail
phytoplankton
2. (a) From the food web above, write down 2 different food chains:
______________________________________
Name ______________________________________ per _____ date ___________
(b) Name the producer ____________________
(c) Name the primary consumers
(d) Name the secondary consumers
(e) Name the tertiary consumer
(f) Are any organisms in more than one trophic level? If so, which ones and in which trophic
levels are they?
(g) Explain how the organisms would be affected if the snail population died out.
Heron
Pelican
Large fish
Crab
Zooplankton
Phytoplankton
Small fish
Prawn
Mud whelk
Eel grass
3. (a) From the food web above, write down 2 different food chains:
_________________________________________
(b) Name the producer
(c) Name the primary consumers
(d) Name the secondary consumers
(e) Name the tertiary consumer
(f) Are any organisms in more than one trophic level? If so, which ones and in which trophic levels are
they?
(g) What would happen to the food web if a marina being built destroyed the eel grass area?
(h) What effect would overfishing of crabs, both male and female, have on the other organisms?
(I) Boat anti-rotting paint contains lead- the heavy toxic element which biologically accumulates along a
food chain in the same way as does mercury and DDT. Which organism would suffer the greatest effect
if large quantities of anti-rotting paint were released into the waterways? _____________________
Explain: