Unit 3: Interaction and Interdependence
Topic 3.8: Populations and Communities Questions
Practice 20 exam-style questions for IB Biology Topic 3.8. Review the question stems below, then unlock the full Question Bank to access markschemes, model answers, and AI grading.
1State1 mark
State what is meant by the term keystone species.
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State the interspecific relationship in which both species are harmed.
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Which interspecific relationship benefits BOTH species?
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State the sampling method used to estimate the population size of an animal that moves around its habitat.
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Which of the following is an ABIOTIC factor that can affect where a species lives?
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State whether competition between two species for the same food is an abiotic or a biotic factor.
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State what is meant by the carrying capacity of a habitat for a population.
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Which term means all the individuals of one species living in the same area at the same time?
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Which sampling method is most suitable for estimating the number of dandelion plants in a meadow?
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State the term for the process in which a plant releases a chemical that inhibits the growth of other plants nearby.
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An interaction between two species harms BOTH organisms.
Which interspecific relationship is this?
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At the carrying capacity, what is true of the birth rate and death rate of the population?
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State what is meant by ecological succession.
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A plant releases a chemical into the soil that inhibits the growth of other plants nearby.
What is the name of this process?
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Why do ecologists usually estimate a population's size from a sample instead of counting every individual?
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Which statement best describes what makes a species a keystone species?
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What does species richness measure in a community?
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State the meaning of the term species richness.
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Which term means the place (the type of environment) where a species or community normally lives?
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An ecologist wants to estimate the size of a population of fast-moving beetles.
Which sampling method is most suitable?
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