Download Pond Food Chain/Web Activity

Biology Life in a Pond Food Chain/ Web Activity
DO NOT WRITE ON THIS SHEET. RETURN AT THE END OF THE PERIOD.
Background
Communities are groups of organisms (populations) that maintain persistent associations with each other. The
members of a typical community include plants, animals, and other organisms that are biologically interdependent
through predation, parasitism, and symbiosis. The structure of a biotic community is largely characterized by the
trophic (feeding) relationships among its member species. These relationships are often represented simplistically
as a food chain. Each link in the food chain represents a trophic level encompassing either producers or
consumers.
In most communities, green plants are the dominant producers. They represent the first level in a typical food
chain. Plants capture kinetic energy from sunlight and, through the process of photosynthesis, manufacture
organic molecules (e.g. simple sugars) from carbon dioxide and water. The captured energy is "stored" in the
chemical bonds of these molecules. Most of the stored energy is used by plants for their own survival and
growth, some is lost as heat, and only a small amount (10%) passes on to consumers when the plant is eaten, or
to decomposers when the plant dies. Primary consumers occupy the second level of a food chain. These
animals, often called herbivores, survive by feeding exclusively on plants or plant products. Any remaining
levels in the food chain are occupied by secondary or tertiary carnivores (predators or parasites of other
carnivores). Since energy becomes limiting at the uppermost trophic levels, there are seldom more than four or
five links in a terrestrial food chain.
Procedure
1. Complete questions #1-3 on the worksheet using the image of the food web provided.
2. Cut apart the pictures with the pictures of different organisms into cards.
3. Separate the cards into the different categories (producers, primary, secondary, and tertiary consumers) and
record the organisms on the student worksheet.
4. In the three blank cards, write three additional organisms that would fit into your food chains.
5. Create four food chains of varying length using the cards provided. Record your food chains on the worksheet.
6. Lay out two of your food chains from #5 starting with producers on the left with the consumers spread across
the page to right.
7. Glue the cards onto the piece of paper and draw arrows to show the direction of energy flow. (Arrows always
point in the direction from prey to predator)
8. Once you have glued your food chains, create a food web by connecting the two chains: draw arrows to each
of the organisms that have a feeding relationship with each other. (You must use at least 10 of the cards,
including the 3 with stars)
9. Complete all sections of the lab report.
Adapted from: T. Trimpe 2006
http://sciencespot.net
Name_____________________________________
Biology Life in a Pond Food Chain/ Web Lab Report
Use the food web to complete questions 1 and 2.
1. List the organisms that are the producers.
2. Identify all of the organisms in the food chain by writing the following letter/numbers next to each
organism.
P - producer
1 - primary consumer
2 - secondary consumer
3 - tertiary consumer
3. What would happen to the limpet population if the mussels were to die out due to a disease?
4. How would the zooplankton be affected if the fish population were to increase?
5. How would the whelk population be affected if crabs were removed?
Food Chains
Cut apart the organism csrds and sort them into three categories: producers, consumers, and decomposers. Create
four food chains in the space below. Remember, the first trophic level must start with a producer, second level is
a primary consumer, third level is a secondary consumer, and the fourth level is a tertiary consumer. If there is a
fifth level (rare), they would be quartenary consumers.
trophic level
1
trophic level
2
trophic level
3
trophic level
4
trophic level
5
Food Web
Use at least 10 of the cards to create a food web to show the relationship between the organisms in a pond habitat.
You must use the three cards with the stars. After you have created the food web, glue the pieces onto a
separate sheet of paper and add arrows to show the feeding relationships.
Analysis Questions
1. What would happen to your food web if the aquatic plants died out because of pollution?
2. what would happen to your food web if the population of great blue heron was to double?
3. Asian carap consume zooplankton, which many fishes feed on in their jevenile stages, and have not known
predators. How would the introduction of an Asian carp affect your food web?