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GCSE Biology · key term
A square frame of known area used to sample plants or slow-moving organisms.
Used by AQA, Edexcel and OCR
Specification 4.7.2.1 · Paper 2
A square frame used to sample organisms within a known area.
Revise: Sampling Techniques and Species AbundanceA quadrat is a square frame of known area. It is useful for plants and other organisms that stay in place while they are counted. To sample a field without choosing favoured spots, place two tape measures at right angles along its edges to make a coordinate grid.
Specification 9.5, 9.6 · Paper 2
For a population estimate, use the area of one quadrat and the total habitat area in the same units.
Random coordinates reduce bias; placing quadrats only where the species is easy to see does not.
When describing a method, state where the transect is placed, that quadrats are positioned at regular measured intervals, what is recorded in each quadrat and which abiotic factor is measured at the same positions.
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A square frame of known area used to sample organisms, especially plants or slow-moving organisms, within a habitat.
A quadrat marks out a small, known area so that the organisms inside it can be sampled consistently. It is most suitable for plants and other organisms that do not move away while being counted.
A frame enclosing a known area in which organisms can be counted or their coverage measured.
Specification B6.1a, PAG 3 · Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
A square frame placed on the ground to define a known area in which organisms can be counted or their cover estimated.
Revise: Field investigationA quadrat is a frame of known area, useful for plants and other organisms that stay in place. First mark out the survey area and identify the species to be counted, using an identification key if needed. Place two measuring tapes at right angles along the edges of the area.
Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
A square frame used to sample plants or slow-moving animals in a known area.
Revise: Field InvestigationsA quadrat is a square frame with a known area. To estimate abundance across a fairly uniform area, mark out its boundaries and choose several quadrat positions using random coordinates. Place the same quadrat at each position and count the target species inside it.
A square frame of known area used to sample organisms within its boundaries.
A frame that marks out a known area in which organisms can be counted or their cover estimated.