Questions Energy Flow Pyramids
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MAY 2014 YEAR 11 PRE-DIPLOMA BIOLOGY Ecological Pyramids Answer the following questions by writing the answers after the questions. 1. a) What kind of ecological pyramid is depicted in the above diagram? a. A pyramid of Numbers? Yes b. A pyramid of Energy? No c. A pyramid of Biomass? No b) Describe the shape of this ecological pyramid. Why doesn’t this pyramid collapse even though there are fewer organisms at the first trophic level than at the second trophic level? Because the oak is big enough to support so many caterpillars, the oak has enough energy to sustain 2000 caterpillars. c) What happens to the energy stored in each trophic level as one moves up through the levels in the pyramid? The energy decreases because the energy has already been used with other organism in the lower trophic levels. 1
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Transcript of Questions Energy Flow Pyramids
MAY 2014 YEAR 11 PRE-DIPLOMA BIOLOGY
Ecological PyramidsAnswer the following questions by writing the answers after the questions.
1.
a) What kind of ecological pyramid is depicted in the above diagram?
a. A pyramid of Numbers?
Yes
b. A pyramid of Energy?
No
c. A pyramid of Biomass?
No
b) Describe the shape of this ecological pyramid. Why doesn’t this pyramid collapse even though there are fewer organisms at the first trophic level than at the second trophic level?
Because the oak is big enough to support so many caterpillars, the oak has enough energy to sustain 2000 caterpillars.
c) What happens to the energy stored in each trophic level as one moves up through the levels in the pyramid?
The energy decreases because the energy has already been used with other organism in the lower trophic levels.
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MAY 2014 YEAR 11 PRE-DIPLOMA BIOLOGY
2.
a) (i) What kind of ecological pyramid is depicted in the above diagram? A pyramid of biomass
(ii) Provide an explanation to justify your answer to (i) above.
The pyramid has numbers of mass per meters square which shows us that is a pyramid of biomass.
b) Describe two complications that can arise when biologists use a pyramid of biomass.
1. Because of water in the organism they have to be killed and dried so they can record their measurements.
2. As the organisms have to be killed and only small samples can be tested , and may not be representative.
3. A grassland ecosystem in Alberta receives 1500 kJ of sunlight. One food chain in this community is depicted as follows:
grass grasshoppers blackbirds hawks
a) Draw an ecological pyramid that illustrates the transfer of energy in this community. Using the rule of 10, determine the amount of energy that is stored at each trophic level. Include all relevant labels.
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MAY 2014 YEAR 11 PRE-DIPLOMA BIOLOGY
b) A farmer sets up a buffalo farm in this ecosystem. Over time, the buffalo greatly reduce the grass biomass in the community. Explain how the introduction of this new species could affect the amount of energy transferred within the food chain that is shown above.
The buffalo will decrease the amount of grass by half, which will decrease the source of energy for all other trophic level by half too. The grasshoppers for example will receive only 75 kilojoules instead of 150kilojoules which is half. All the other trophic levels will also receive only half of what they usually receive. This can lead to a decrease on species at a next trophic level.
Hawk 1.kKJ
H
Black birds 15KJ
Grasshoppers 150KJ
Grass 1500kj
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