1
IB Environmental Systems and Societies
Grade 11
First Semester Examination
Name: ________________________
Print in Block Letters
Teacher: Mr. Wayne Rice
Total: _______ / 100
Percentage: _______ %
Instructions:
1) Please read all the questions carefully before answering.
2) If you do not know the answer to a question move onto the next question.
3) Answer all questions on the answer paper provided.
4) The use of calculators is allowed.
Section A:
Section B:
20 marks
80 marks
20 minutes
100 minutes
Total:
100 marks
120 minutes
2
Section A: Short-answer and data-based questions
1) Give one word or phrase or number for the following questions:
a) An assemblage of parts, and their relationships, forming a whole.
[1]
b) A system which exchanges matter and energy.
[1]
c) A stable ecosystem will be in . . . (i) . . . equilibrium, achieved largely through
mechanisms of . . . (ii) . . .feedback.
[2]
d) The amount of energy that is available to living things decreases as it is transformed
and passed along food chains.
[1]
Questions e, f, and g refer to the diagram below.
e) Provide the name for the organisms in the storage box labelled X.
[1]
f) The gain in energy or biomass per unit time after allowing for respiration losses.
[1]
g) What is the net productivity of the decomposers in kJ m-2 yr-1?
[1]
h) The graph below shows changes in the biomass, productivity and respiration of a
community during the process of forest succession.
During which stage is the mean net productivity the lowest?
[1]
i) The total quantity of organic matter produced by photosynthesis per unit area per unit
time is the…
[1]
3
j) A collection of ecosystems sharing similar climatic conditions.
[1]
k) What a species does in its environment, including its job and all its interactions.
[1]
l) A lion eats a zebra. What type of population interaction is this an example of?
[1]
m) A group of organisms of the same species living in a given area.
[1]
n) The maximum number of species that a given area can support.
[1]
o) What is a typical characteristic of a K-strategist?
[1]
p)
Lines I, II and III are survivorship curves for three different populations in an ecosystem.
Which row best describes the nature of the three populations? (K-strategists, R-strategists,
Intermediate strategists)
[3]
q) A stable community of organisms produced as a result of ecological succession.
[1]
Section A: 20 marks
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Section B: Longer Questions
2) Explain what is meant by steady state equilibrium.
[2]
3) Draw a diagram representing the positive feedback mechanism of global warming with
regards to its effects on altered water vapour levels.
[5]
4) a) Draw a flow and storage (systems) diagram for the water cycle based on the
information found in the table below. Remember to make storage boxes and flow arrow
widths correspondent to the proportions of these volumes.
[8]
Storages
Snow and ice
Groundwater
Lakes and rivers
Oceans
Atmosphere
Soil
Flows
Precipitation over oceans
Precipitation over land
Ice melt
Surface run-off
Evapotranspiration from land
Evaporation from sea
Water volume (km3 x 103)
27 000
9 000
250
1350 000
13
35 000
385
110
2
40
70
425
b) Provide two examples of transformations and two examples of transfers from your
diagram in your answer to 4a).
[4]
5) In a short paragraph discuss sustainable living in the context of synergy.
[6]
6) Study the ecological pyramid below and answer the questions below.
a) Distinguish between the terms predator and parasite.
[2]
b) (i) State the name of the type of diagram shown above.
(ii) Suggest why there are often more organisms at the third trophic level than at the
second trophic level in a food chain containing parasites.
c) Explain why the energy available to the predators in a food chain is much less than
that fixed by the producers.
[1]
[2]
[3]
5
7) The diagram below shows inputs and outputs of water associated with a lake system in
units of 106 m3 yr−1.
a) Assuming the system is in steady state equilibrium, calculate X.
[2]
b) State whether the lake is an open, closed or isolated system. Give a reason for your
answer.
[2]
c) Suggest how an increase in mean global temperatures might affect the flows shown in
the diagram.
[2]
8) The diagram below shows the relative size of some energy flows between four types of
organisms in a small pond, over one year.
What is the gross productivity of the primary consumers?
[2]
9) Biomes are largely determined by their prevailing climatic conditions. From the graph
below identify the biomes most likely to be found in the given climatic conditions ( I, II, III,
IV).
[4]
10) The following questions refer to marine ecosystems.
a) Name an organism which exists at each of the following trophic levels
i) Producer
ii) Herbivore
iii) Carnivore
[3]
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10) b) Choose one of the organisms named in 10(a) above, and explain how a named abiotic
factor and a named biotic factor might influence the abundance of that organism.
[4]
11) The figure below represents a pyramid of biomass for a food chain in an aquatic
ecosystem.
a) Suggest two reasons why the biomass of fish may be greater than the biomass of
zooplankton.
[2]
b) The productivity: biomass ratio (P:B) represents the annual net productivity per unit of
biomass. For example, from the P:B ratios given below it can be seen that each gram of fish
biomass produces 2.2 g of new biomass annually.
Using the data in (a) and the P:B ratios below, calculate the productivity for each trophic
level and plot a pyramid of productivity on the axes below.
[6]
i) Fish
ii) Zooplankton
iii) Phytoplankton
c) State the two factors that would need to be measured in order to estimate the gross
productivity of the fish population in g m-2 yr-1.
[2]
12) The area graph below shows the change in the total above-ground dry weight plant
biomass in an ecosystem as it undergoes succession. The example given is the development
of forest following the retreat of a glacier in Alaska. The graph also shows the proportion of
the total biomass made up by different species of tree: willow, alder, spruce and hemlock
(Tsuga).
Question 12 continues on the next page.
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a) Define the term succession.
b) Define the term biomass.
c) State and explain the changes in the total biomass shown in the graph.
d) Using the graph, identify the two most important species in the climax stage of this
succession.
e) Using the graph, identify the most important species in the pioneer stage of this
succession.
[1]
[1]
[4]
[2]
[1]
13) The graph below shows the change in the population of water fleas (a small aquatic
invertebrate) over a 14 day period at three different temperatures.
a) Compare the carrying capacity at 19°C and 24°C.
[2]
b) State one factor, other than temperature, that might influence the rate of population
growth of an organism.
[2]
c) Explain why it is difficult to give a precise value for a country’s carrying capacity for a
human population.
[2]
14) Describe and explain, with examples, how diversity and productivity differ in pioneer
and climax communities.
[7]
15) What is an Environmental Impact Assessment (EIA) and why is it important?
[2]
Section B Total: 80
Total: 100 marks