A germinating acorn was positioned so that its young root grew horizontally through damp compost. It was kept in darkness. After 18 hours, the root had curved downwards.
Cells were measured in the growing region just behind the root tip.
| Side of the root | Mean cell length in μm\mu\text{m}μm |
|---|---|
| upper side | 72 |
| lower side | 48 |
Explain how the pattern of cell lengths shown in the table developed.
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.