Edexcel GCSE Biology

Sampling & quadrats

Edexcel GCSE Biology revision on Sampling & quadrats. Aligned to the Pearson Edexcel GCSE Biology 1BI0 specification. This bank has 5 practice questions on this topic.

Sample questions (3 of 5)

  1. Question 1

    Why must a researcher use random sampling when investigating the distribution of daisies across a large field?

    • A) To ensure the sample is representative
    • B) To remove all possible bias from data
    • C) To increase the total area covered
    • D) To count every plant in the field
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    Answer: To ensure the sample is representative

    If a researcher chooses where to place quadrats, they might unconsciously pick spots with more daisies, leading to biased results. Random sampling ensures that every part of the habitat has an equal chance of being selected, which is essential for obtaining a representative estimate of the total population.

  2. Question 2

    Which technique is most appropriate for measuring the change in vegetation across a sand dune where an environmental gradient exists?

    • A) Systematic transect sampling
    • B) Random quadrat placement
    • C) Capture-recapture method
    • D) Point frame observation
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    Answer: Systematic transect sampling

    When an abiotic factor like light or moisture changes across a habitat, a transect line is used to record data at regular intervals. This systematic approach allows biologists to correlate specific environmental changes with shifts in plant or animal distribution, unlike random sampling which would mask these patterns.

  3. Question 3

    What is the primary purpose of using a quadrat frame when estimating the population of non-motile organisms?

    • A) To create a known sampling area
    • B) To trap the organisms inside
    • C) To improve total plant growth
    • D) To exclude all dead material
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    Answer: To create a known sampling area

    A quadrat defines a specific, measurable area, such as 0.25 square metres. By counting the organisms within this known area, scientists can calculate the mean density and then use this to estimate the total population across the entire habitat.

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2 more questions on Sampling & quadrats — plus mistakes tracking and spaced repetition across the whole Biology spec.

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