Name:
Pre Mac-Mods
1. In the food chain shown above, which organism is the primary producer?
2. Which organism occupies the third trophic level?
3. What is the name for the diagram below? What does the diagram show?
4. Fill in the ecological pyramid using the organisms from the diagram in #3.
Name:
Food Chains and Food Webs:
Examples from a salt marsh
Directions: Follow along in class to complete this worksheet.
Food Chains
1. A
is the simplest path that energy can take through an ecosystem.
2. Each level in the transfer of energy through an ecosystem is called a
3. Energy enters the ecosystem from the
.
4. Draw an example of a food chain using organisms found in a salt marsh:
5. Label the different trophic levels in food chain you just drew.
6. In general, the first trophic level of any food chain will consist of
the second trophic level will consist of
higher, trophic level will consist of
7. A
, and the third, or any
.
is a consumer that decomposes organic material and returns the
nutrients to the soil, water, and air making the nutrients available to other organisms.
Food Webs
1. A
represents many interconnected food chains describing the
various paths that energy takes through an ecosystem.
The energy available in an ecosystem can be illustrated with a food web diagram. As a class we are
going to create a food web diagram of the salt marsh ecosystem.
2. Draw an example of a food web diagram of a salt marsh ecosystem.
3. What happens when humans become involved and severely disrupt the flow of energy through an
ecosystem?
4. What can be done to prevent this problem?
Ecological Pyramids
1. Similar to food chains,
show how energy flows through ecosystems.
a. The base of the pyramid contains the
.
b. The second level of a pyramid contains the
.
c. The third, and any higher, level of a pyramid contains the
2. Pyramids can be used to show relative amounts of
.
,
, or
of organisms at each trophic level in an ecosystem.
a. In an energy pyramid, only about
% of the energy available is used by organisms.
The rest of the energy is lost to the environment.
b. In a number pyramid, the total numbers of individual organisms tend to
as you go up the trophic levels.
c. In a biomass pyramid, since the number or organisms at each trophic level is reduces, the
biomass at each level is
as well.
3. Fill in the following ecological pyramid using examples from the salt marsh ecosystem.
Name:
Post Mac-Mods
1. What is the name for the diagram shown above? What does it show?
2. How many trophic levels are shown in the diagram above?
3. In the food web shown above, which organism is the apex predator (the one that never gets eaten)?
4. In the food web shown above, what does a leopard seal eat?
5. According to an energy pyramid, approximately how much energy does each trophic level get from the
level below?