Modern agricultural systems rely heavily on elite monocultures of crop plants, such as highly uniform, high-yielding varieties of modern bread wheat (Triticum aestivum).
Explain, with reference to selective breeding, why it is crucial for plant breeders to conserve and maintain viable populations of wild ancestral wheat relatives and traditional landraces.
22 exam-style questions on OCR A A Level Biology Classification and evolution. Each one has a worked solution and a mark scheme showing where the marks go.