A conservation group estimates the number of flowering heather plants in a heathland measuring 1200 m2. They use a random number generator to choose coordinates for five quadrats, each with an area of 2 m2. The numbers of flowering heather plants counted are shown in the table.
| Quadrat | Number of flowering heather plants |
|---|---|
| 1 | 11 |
| 2 | 15 |
| 3 | 12 |
| 4 | 14 |
| 5 | 13 |
Explain how choosing the quadrat coordinates in this way reduces selection bias.
Calculate the estimated number of flowering heather plants in the heathland.
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.