Scientists record the organisms in the same area of a coral reef at two different times.
Which result shows that biodiversity has decreased?
A new species of crab is recorded, although two species of fish become less common.
Every species is still present, although the seaweed now covers less of the reef.
Several species are no longer present, although some remaining species become more numerous.
Every species is still present, although sewage from a nearby town is now found in the water.
84 exam-style questions on AQA GCSE Biology 7.3 Biodiversity and the effect of human interaction on ecosystems, covering 7.3.1 Biodiversity, 7.3.2 Waste management, 7.3.3 Land use, 7.3.4 Deforestation, 7.3.5 Global warming, and 7.3.6 Maintaining biodiversity. Each one has a worked solution and a mark scheme showing where the marks go.