This resource is designed to help GCSE pupils study quadrats. It is suitable for learners studying AQA and OCR science specifications. It can be used to support learning when investigating ecosystems. It is impractical to count all of the organisms in a population such as a field or lawn, as a result, biologists sample a small area to estimate the size of a population. One of these methods uses a quadrat. This resource can be used independently or as an aid to practical investigations that learners may complete using quadrats. Your download will include worksheets that are differentiated for ability. This will cover the random placement of quadrats for a fair test, opportunities to calculate the mean and estimate the number of daisies buttercups in an field. This can be completed as a whole class, or set as an individual task. Answers to the worksheet are not included as the first task is to randomly place quadrats on the diagram provided and so no one answer will be correct for every learner. Also included is an exam question along with a mark scheme.