| Date | November 2018 | Marks available | 2 | Reference code | 18N.1.SL.TZ0.3 |
| Level | Standard Level | Paper | Paper 1 | Time zone | Time zone 0 |
| Command term | Identify | Question number | 3 | Adapted from | N/A |
Question
Figure 6: Simplified Algonquin Provincial Park food web
The resource booklet provides information on Algonquin Provincial Park in Canada. Use the resource booklet and your own studies to answer the following.
With reference to Figure 6, draw a food chain that includes four trophic levels.
Identify two ways that human activity in Algonquin Provincial Park may affect the food web.
Markscheme
This question requires “Resource Booklet - Nov 2018 SL paper 1”, available under the "your tests" tab > supplemental materials.
Award [1] for 4 named species correctly identified as being in the same food chain and [1] for arrows going in the correct direction.
For example:
spruce/maple tree → woodland jumping mouse → red fox → Algonquin wolf
spruce/maple → snowshoe hare → red fox → Algonquin wolf
spruce/maple → fairy moth → grey jay → northern saw whet owl.
Do not accept just “trees/vegetation”.
Do not credit arrows if more than one set of arrows given eg illustrating waste/respiration.
This question requires “Resource Booklet - Nov 2018 SL paper 1”, available under the "your tests" tab > supplemental materials.
hunting/trapping/fishing removes species from the food chain / hunting of beavers/moose reduces food availability to predators such as wolves/bears;
logging (forest management) removes species from food chain;
trampling (from tourist)/development of tourism facilities could reduce food source/first trophic level;
introduced species, eg cats/dogs, add additional predators or prey;
removal of dams may lead to loss of pond species eg bullhead lily/dragonfly/bullfrogs/pearl dace reducing food source for other species;
protection of wolves increases wolf numbers, thereby increasing predation on beaver/moose/hare etc. reducing herbivore numbers.
Note: For credit the human activity must be explicitly linked to effect on the food web.
Do not credit if activity is only linked to habitat loss.
Do not accept “deforestation/agriculture or only “pollution”.
Accept other reasonable responses.
Examiners report
This question was answered well with most candidates correctly identifying 4 species and drawing arrows in the correct direction within the food chain. Drawings/sketches of the species are irrelevant and therefore candidates should not use valuable time in the exam doing this. Marks were most commonly lost for arrows pointing in the wrong direction and a few students confused a food chain with a food web or a trophic pyramid.
The majority of candidates only achieved one mark for this question. A common error was to discuss human activities for which there was no evidence within the resource booklet e.g. deforestation or agriculture. In addition, many answers were too vague and did not link the human activity to the effect on the food chain.
Syllabus sections
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14N.2.SL.TZ0.3a:
Distinguish between a pyramid of numbers and a pyramid of productivity.
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17N.2.SL.TZ0.7a:
Outline how soil can be viewed as an ecosystem.
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17N.2.SL.TZ0.4a:
Describe the role of primary producers in ecosystems.
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19N.1.SL.TZ0.2e:
Suggest why the St Lawrence River beluga whale population has not recovered despite being given protected status in 1983.
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14M.1.SL.TZ0.1a.i:
State the source of energy for this ecosystem.
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16M.1.SL.TZ0.1e.i:
State its trophic level in the ecosystem.
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19M.1.SL.TZ0.7:
Explain two ways in which mangroves improve the water quality for primary producers within marine ecosystems.
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18N.1.SL.TZ0.3a:
With reference to Figure 6, draw a food chain that includes four trophic levels.
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18M.2.SL.TZ0.5b:
Suggest the procedures needed to collect data for the construction of a pyramid of numbers for the following food chain:
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17N.1.SL.TZ0.7:
To what extent might Iceland be viewed as a role model for sustainability by other countries?
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19N.1.SL.TZ0.2d:
With reference to Figure 8, explain why the beluga whale is more at risk from toxic pollutants, such as heavy metals and persistent organic pollutants (POPs), than most other organisms in its food web.
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19M.1.SL.TZ0.8:
With reference to Figure 5, describe how loss of a coral reef ecosystem could impact a neighbouring seagrass community.
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19N.1.SL.TZ0.3b:
With reference to Figure 9(a), outline how the round goby both positively and negatively affects the St Lawrence River ecosystem.
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16M.2.SL.TZ0.1c.iii:
Identify four factors that would affect the primary productivity of forest plantations in the Copperbelt Province.
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18N.1.SL.TZ0.10a:
With reference to Figure 7(a), outline one reason why there are more beaver remains in wolf faeces during summer.
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17N.1.SL.TZ0.5c:
Identify two reasons why the future size of the Atlantic puffin population is difficult to predict.
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18M.2.SL.TZ0.4b:
Explain how a community of trees in a woodland may be considered a system.
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19N.1.SL.TZ0.2a:
Using Figure 6(c), identify a food chain in the St Lawrence River ecosystem that has five trophic levels.
- 17N.1.SL.TZ0.5a.ii: Identify one argument against humans hunting puffins.
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14M.1.SL.TZ0.4d:
Explain how the use of non-biodegradable pesticides on farmland may affect the human food chain.
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19M.2.SL.TZ0.1d:
Outline two ways in which the food web is likely to change as a result of succession.
- 18N.2.SL.TZ0.4c: Using examples, discuss whether habitat conservation is more successful than a species-based...
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17M.2.SL.TZ0.1d:
With reference to the concepts of bioaccumulation and biomagnification, outline how the concentration of DDT has changed along the food chain.
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16M.2.SL.TZ0.1d.i:
With reference to Figure 7, state the most common ecosystem in Zambia.
- 18N.1.SL.TZ0.1: Identify one ecosystem in Algonquin Provincial Park.
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17M.2.SL.TZ0.1b:
State the trophic level labelled X in Figure 1.
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19N.1.SL.TZ0.1d:
Outline why estuaries are highly productive ecosystems.
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17N.1.SL.TZ0.5b:
With reference to Figure 8(c) state the impact that an increase in the mackerel population might have on the Atlantic puffin population.
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14N.1.SL.TZ0.2b:
Elephants eat a variety of vegetation: grasses, shrubs, leaves and small tree seedlings. Describe the impact on a grassland ecosystem of the main large herbivore being removed.
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16N.2.SL.TZ0.4a:
Outline why top carnivores are vulnerable to non-biodegradable toxins.
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14N.2.SL.TZ0.4b:
Explain the transfer of energy through an ecosystem. Support your explanation with a labelled diagram.
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16N.1.SL.TZ0.4c:
Describe how the second law of thermodynamics operates in relation to the transfer of energy within the Silver Springs ecosystem.
- 18M.2.SL.TZ0.3a: Identify one producer in the system illustrated in Figure 3.
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16N.1.SL.TZ0.4d:
Distinguish between a pyramid of numbers and a pyramid of productivity.
