Researchers grew two groups of young plants in identical conditions. In one group, one transport tissue formed much less lignin than usual.
The same force was applied to each stem. The researchers then measured the transport tubes and analysed the upper leaves.
| Plant group | Mean internal diameter of transport tubes after the force was applied / µm | Mean increase in mass of mineral ions in the upper leaves during 12 hours / mg |
|---|---|---|
| Usual amount of lignin | 30 | 5.6 |
| Much less lignin | 12 | 2.1 |
Calculate the percentage decrease in the mean internal diameter of the transport tubes in the plants with much less lignin.
Name the transport tissue affected. Explain why less lignin caused the smaller increase in the mass of mineral ions in the upper leaves.
74 exam-style questions on AQA GCSE Biology 2.3 Plant tissues, organs and systems, covering 2.3.1 Plant tissues and 2.3.2 Plant organ system. Each one has a worked solution and a mark scheme showing where the marks go.