A native dune flower produces seeds only when an insect carries pollen between two plants. An introduced creeping plant spread across the dunes and competed with the flower for light and space. By the time the creeping plant was removed, few dune flowers remained.
Light intensity, soil moisture and pollinating-insect numbers had returned to their earlier levels. Pollinating insects usually moved no more than 25 m between flower visits, while every surviving dune flower was at least 90 m from another survivor. The number of dune flowers continued to fall.
What is the most likely reason that the flower population continued to decline?
The surviving flowers received too few mineral ions from the soil to produce seeds.
The surviving flowers had too few insects visiting them to obtain enough food.
Separation greatly reduced the chance of pollinating insects carrying pollen between surviving dune flowers.
Competition with the creeping plant left surviving flowers with too little space to grow.
82 exam-style questions on AQA GCSE Biology 7.1 Adaptations, interdependence and competition, covering 7.1.1 Communities, 7.1.2 Abiotic factors, 7.1.3 Biotic factors, and 7.1.4 Adaptations. Each one has a worked solution and a mark scheme showing where the marks go.