A freshwater pond has high biodiversity. One species of water snail, which is eaten by some fish, declines.
Why is the pond likely to remain stable after the snail population declines?
Fish can feed on other species when the snail population is small.
Each snail has more offspring when many other species live in the pond.
Fish need less food when a pond contains a greater variety of species.
The snail depends on the fish, so fewer snails do not affect the fish.
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.