1. Guru charan kumar
IB ESS
2013
SYSTEMS & MODEL WORKSHEET 2
Figure 1 shows energy flow through a food chain.
Figure 1
primary producers
–
900 kcal m 2 yr–1
(a)
(i)
cattle
256 kcal m–2 yr–1
human
6.6 kcal m–2 yr–1
Calculate the percentage energy loss to humans from the initial input of
900 kcal m–2 yr–1.
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(2)
(ii)
Explain why farming systems based on crop production are more energy
efficient than harvesting from the sea.
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(2)
(iii)
Suggest two ways in which energy may be lost from the system.
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(2)
(b)
(i)
Suggest three reasons why livestock (cattle, goats, sheep, etc.) form a part of
most farming systems.
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2. Guru charan kumar
IB ESS
2013
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(3)
(ii)
Figure 2 shows a systems diagram for a farm. Annotate the diagram to show
two inputs and two outputs, and their possible environmental impacts.
Figure 2
INPUTS
Input
Impact
Input
Impact
OUTPUTS
Output
Impact
Output
Impact
(4)
(Total 13 marks)