Four potato tubers each produced one young shoot. The tubers were positioned so that each shoot was horizontal and were then kept in darkness.
After 24 hours, the shoots had curved upwards. The angle through which each shoot curved was measured.
| Shoot | Angle through which the shoot curved |
|---|---|
| 1 | 28∘28^\circ28∘ |
| 2 | 34∘34^\circ34∘ |
| 3 | 25∘25^\circ25∘ |
| 4 | 33∘33^\circ33∘ |
Tests showed that more auxin was present on the lower side of each shoot.
Calculate the mean angle through which a shoot curved.
State why the shoots were kept in darkness.
Explain how the unequal distribution of auxin caused each shoot to curve upwards.
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.