A class is estimating heather abundance across a large, level area of heathland. The area has no visible environmental gradient, and counting every heather plant would take too long.
How should the class position its quadrats to obtain a representative estimate of heather abundance across the area?
at coordinates chosen using a random number generator
only around the edge of the area, where access is easiest
at regular intervals along one straight line across the area
wherever each quadrat lands after being thrown
82 exam-style questions on Edexcel GCSE Biology 9.1 Ecosystems and interdependence, covering 9.1.1 Levels of organisation in ecosystems, 9.1.2 Abiotic and biotic factors, 9.1.3 Importance of interdependence, 9.1.4 Parasitism and mutualism, and 9.1.5 Determining number of organisms in an area. Each one has a worked solution and a mark scheme showing where the marks go.