Students estimate plant abundance on a sand dune using quadrats at regular intervals along one belt transect. A second group samples the same dune using many random coordinates over the whole area.
Which statement best compares what these methods can show?
Both methods directly show that one abiotic factor causes changes in abundance.
The transect shows change with distance; random sampling estimates overall abundance.
Random sampling shows change with distance; the transect estimates every population exactly.
Both methods directly count every individual throughout the whole dune ecosystem.
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.