A root lies horizontally in the dark. Auxin builds up on the lower side of the root and the root then bends downwards. Which statement explains this?
Auxin inhibits cell elongation, so the lower side grows more slowly
Auxin inhibits cell elongation, so the upper side grows more slowly
Auxin increases cell elongation, so the lower side grows more quickly
Auxin increases cell elongation, so the upper side grows more quickly
59 exam-style questions on AQA GCSE Biology 5.4 Plant hormones, covering 5.4.1 Control and coordination and 5.4.2 Use of plant hormones (HT only). Each one has a worked solution and a mark scheme showing where the marks go.