A new predator is introduced to an island.
The predator eats a small species of bird.
The birds feed on insects, and the insects feed on plants.
After a few years, the number of plants on the island decreases.
Which statement explains the decrease in the number of plants?
The predator eats the plants, so there is less food left for the insects.
Fewer birds eat the insects, so more insects survive and feed on the plants.
Fewer birds compete with the plants for light, so the plants grow less well.
More insects pollinate the plants, so the plants grow too quickly and die.
111 exam-style questions on OCR GCSE Biology 4.1 Ecosystems, covering 4.1.1 Cycling of materials in ecosystems, 4.1.2 Microorganisms in cycling materials, 4.1.3 The carbon and water cycles, 4.1.4 Factors affecting decomposition, 4.1.5 Levels of organisation in an ecosystem, 4.1.6 Abiotic and biotic factors affecting communities, 4.1.7 Interdependence and competition, 4.1.8 Trophic levels, 4.1.9 Pyramids of biomass, and 4.1.10 Efficiency of biomass transfers. Each one has a worked solution and a mark scheme showing where the marks go.