Unit 2: Ecosystems and Ecology

Topic 2.1: Species, Populations Questions

Practice 20 exam-style questions for IB ESS Topic 2.1. Review the question stems below, then unlock the full Question Bank to access markschemes, model answers, and AI grading.

1list2 marks
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List four abiotic factors that can affect the distribution of organisms in an ecosystem.
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2distinguish2 marks
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Distinguish between an organism and a species.
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3outline2 marks
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Outline the steps involved in using a dichotomous key to identify an organism.
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4distinguish2 marks
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Distinguish between abiotic and biotic factors, giving one example of each.
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5define1 mark
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Define the term sustainability in the context of environmental systems.
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6identify4 marks
The graph shows changes in two populations (A and B) over time in an ecosystem.
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7define1 mark
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Define the term resilience in the context of environmental systems.
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8state2 marks
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State the rules for writing a binomial name and provide an example.
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9state2 marks
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State four observable physical features that could be used to identify plant species in the field.
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10distinguish2 marks
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Distinguish between a population and a species, using wolves as an example.
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11define1 mark
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Define the term open system.
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12calculate5 marks
The graph shows population changes in snowshoe hares and lynx over a 16-year period.
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13define1 mark
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Define the term limiting factor.
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14define1 mark
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Define the term carrying capacity.
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15define1 mark
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Define the term community in environmental systems and societies.
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16define4 marks
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Define the term ecosystem and distinguish between biotic and abiotic components, giving examples of each.
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17state1 mark
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State one characteristic of a keystone species in an ecosystem.
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18define1 mark
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Define the term species.
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19define1 mark
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Define the term ecosystem in environmental systems and societies.
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20define1 mark
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Define the term dichotomous key.
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