A plant in a pot was placed on a windowsill. The shoot grew towards the window and the root grew downwards into the soil.
Explain how auxin controls the direction of growth of the shoot and the direction of growth of the root of this plant.
105 exam-style questions on Edexcel GCSE Biology 6.3 Plant hormones, covering 6.3.1 Plant hormones and tropisms and 6.3.2 Commercial uses of plant hormones. Each one has a worked solution and a mark scheme showing where the marks go.