Students use random coordinates to place eight 0.25 m2 quadrats in an area of a school field. The area is 150 m2. They count the dandelion plants in each quadrat.
| Quadrat | Number of dandelion plants |
|---|---|
| 1 | 3 |
| 2 | 5 |
| 3 | 4 |
| 4 | 6 |
| 5 | 2 |
| 6 | 4 |
| 7 | 5 |
| 8 | 3 |
Estimate the number of dandelion plants in the whole area.
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.